{he f . ld ith Pibrary

Prefented to

. The Cornell University, 1869, Peed
BY ee

Goldwin Smith, M. A. Oxons

ie Regius Profeflor of Hiftory in the
f Univerfity of Oxford.

 

 
ni iii

olin,anx
CORNELL
UNIVERSITY,

 

\ LIBRARY | y
TO

SIR WILLIAM FERGUSSON, Barr., F.R.S.

Fellow and Member of the Council of the Royal College of Surgeons, England ;
Surgeon and Professor of Surgery at King’s College, Hospital ; Surgeon Extraor-
dinary to Her Majesty the Queen; and Surgeon in Ordinary to His late Royal
Highness the Prince Consort; late Professor of Human Anatomy and Surgery
R.C.S. Eng., and Examiner on Surgery at the University of London,

This Work is Dediented,
BY THE AUTHOR, '

AS A TRIFLING MARK OF ADMIRATION AND RESPECT
FOR
HIS DISTINGUISHED TALENTS AND BRILLIANT ATTAINMENTS,
AND

IN PLEASING REMEMBRANCE

OF AN UNINTERRUPTED FRIENDSHIP OF TWENTY-SEVEN

YEARS.
LIGHT:

ITS INFLUENCE

ON LIFE AND HEALTH.

BY

FORBES WINSLOW, M_D.,

D.C.L. Oxon. (Hon.),
&c. &c.

LONDON:

LONGMANS, GREEN, READER, & DYER.
1867.
PREP A E,

Tue object of this work is to demonstrate
the inestimable value of light as an hygienic
agent, and to analytically examine its phy-
siological influence in the development of
vital phenomena as manifested in the
animal and vegetable kingdoms.

How impossible it is to exaggerate the
amount of blessing which flows from the

action of the sun, that

“ Great source of day, for ever pouring wide
From world to world the vital ocean round,”

not only on organic, but inorganic matter.
Deprived of its life-generating and health-

sustaining power, the whole of animated
vi Preface.

 

nature would be a sterile blank, and man, the
highest order of intelligent beings, become
blighted in mind and degenerated in body.

In the composition of this volume I
have been under the necessity of levying
contributions on the writings of established
physicists.

I lay no claim to original experimental
research, but desire only to be considered
as a wanderer on the vast shore of science,
picking up here rare shells, there valuable
pebbles, and then classifying them, with
the view of illustrating a branch of inquiry
of deep philosophical interest.

It is impossible to contemplate the facts
scattered through the following pages with-
out being solemnly impressed with a sense
of man’s deep obligation to God,—the Source

of all true Licut,—for thus beneficently
Preface. Vil

 

surrounding our planet by an influence so
pre-eminently conducive to the health and

happiness of the human race.*

CavenpisH Square, Lonpon,
April, 1867.

 

* A portion of the chapter on the “Lunar Ray” appeared
many years ago in a paper of my own, on “Lucid Intervals,”

published in the Psychological Journal.
TABLE OF CONTENTS.

PART I.
THE SOLAR-BEAM.

Origin of light, 1; Healthful and morbid effects of light
upon the animal and vegetable kingdom, 2; No vi-
tality or healthful structure without light, 4; “ Soiar-
air-bath” of the ancients, 4; Bodily deformities , crime,
and mental disease produced by darkness, 5; Health
of those who live in the country as compared with the
inhabitants of manufacturing towns, 7; The absence
of light on miners and colliers, 7; Diseases caused
by the absence of light, 8; Unhealthy condition of
those who labour by night and sleep by day, 9; Deep
mining at Geelong, 10; Development of children re-
tarded by working in mines, 113 Stunted forms ob-
served among the miners of Chimay, 12; Effects of
dampness and deficient nourishment viewed in con-
nexion with want of light, 13; Influence of light upon
animals, 14; Arrest of animal development, 15 ; Blind-
ness of fish caused by want of light, 17-19; Dis-
colouration of different races of men caused by solar
heat, 20 ; The brown skins of the natives of Lapland and
Contents.

 

Greenland, 21 ; White skins of negroes dwelling in the
forests, 22; Black colour contrasted with that of red
or olive negroes, 22; Black, white, and spotted
negroes, 23; Effect of food on_ the hair, 243
Complexions of intemperate persons, 24; Red In-
dians turned white, 25; Influence of the sun in
tropical climates, 26; Albinos of the torrid zone, 27 ;
fish of great oceanic depths, 27; Effect of the absence
of light on the women of the seraglio, 28 ; Statures of
different races of men, 29-31; Mental condition of the
Arabs, 33; Inhabitants of high latitudes possess su-
perior muscular force, 34; Northern countries more
favourable than southern to longevity, 34; Influence
of climate upon physical and mental organization, 36 ;
Effect of deep sea-water on vegetable and animal life,
373; The depth of the ocean, 38-41; Depth at which
solar light penetrates, 41; Temperature of the ocean,
42; Different colours of the sea, 44; Causes of the
varied tints of the sea, 45; Distribution of animal
life in the sea, 46; Classification of marine animals,
47; Microscopic shells found in deep sea deposit, 48 ;
Animal and vegetable life incompatible with certain
altitudes and depths, 50; Amount of pressure at
certain oceanic depths, 51-53 ; Tendency of plants to
follow light, 53; Plants and animals nurtured in dark-
ness altered in colour, 56; Animal and vegetable sub-
stances near the surface of the sea brilliantly coloured,
s9; Brilliant colours of animals and plants in the
tropics, 60; Action of light necessary for development
of vegetable colours, 63; Physiological influence of
Contents. Xi

 

light on the colour of plants, 64; A definite quantity
of heat required for development of plants, 64; Insect
life, 70-74; Chemical influence of light on certain
drugs, 74-77; Effect of light passing through dif-
ferent coloured media on the germination of plants,
78-81; Metals discovered in the solar beam by
the spectroscope, “ Fraunhofer’s lines,” 82-86; Dis-
eases caused by exposure to intense solar heat, 87.

PART II.
THE LUNAR-RAY.

Opinions of the ancients as to the influence of the moon,
89-97; Different parts of the body under planetary
influence, 97; The moon’s power in causing tidal
action, ror; Belief of Spaniards and West India
negroes that the sick always die at ebb-tide, 102;
Principal authorities in support of the theory of pla-
netary influence, 107-112; Drs. Orton and Balfour’s
view of the subject, 12, 113; Periodicity as exhibited
in the phenomena of life, 115-118 ; Historical analysis
of lunar influence, 121 ; Dr. Mead’s views of the in-
fluence of the moon upon the bodily health stated at
length, 120-136; Dr. Pitcairne’s case of lunar in-
fluence, 136; Mr. Cockburn’s singular case, 137;
Hemorrhage from the finger said to come on at the
fall of the moon, 138; Baglioi’s singular case, 139;
Remarkable case of lunar influence occurring to Mr,
Xil

Contents.

 

Ainsworth, 139; Van Helmont on the influence of the
moon on asthma, 139; Historical analysis of Dr.
Balfour’s treatise on the influence of the moon, 141-
146; Mr, Francis Day’s observations on the influence
of the moon at Madras, 147; Dr. Orton on the effect
of the moon on the diseases of tropical climates, and
on the weather, 152-154; Dr. Kennedy’s views on
the same subject, 154 ; Diemerbroeck on the influence
of the moon on the plague, 155; Dr. Lardner’s
opinion of the influence of the moon on the epidemic
fever of Italy in 1693,-158; Dr. James Johnson on
the effect of the moon on the diseases of the liver,
159; Dr. Scott on planetary influence in modifying
diseases of tropical climates, 160; Mr. Hutton on the
effects of the moon at Prince of Wales’s Island, 161,
162; Dr. Moseley on the effect of the varied phases
of the moon on hemorrhages of the lungs, 162-164;
Remarkable case illustrative of the fact, 16 ; Nicholas
Fontana on the influence of the moon on the fever that
occurred at Barrackpore in1777, 166; Dr. Millingen
on planetary influence, 168; Opinions of the Druids of
Gaul on the influence of the moon in vegetable produc-
tions, 170; The mistletoe gathered with a golden
knife when the moon was six days old, 170; The
verbena of the ancients supposed to be under plane-
tary influence, 171; Its medicinal and sacerdotal
virtues, 171 ; Effect of different phases of the moon on
the fructification of plants, 172; Instructions for
planting seeds according to the position of the moon,
173; The Lunar rays calorific, 177; Effect of moon-
Contents. Xiil

 

light on the thermometer, 177, 178; Sudden death and
coma caused by the moon’s light, 179; Effect of full
moon in causing diseases of the brain, 179; A stroke
of the moon, 180; Opinion of the Arabs as to the
morbid influence of the moon, 181; On the modus
operandi of the lunar light, 181 ; Distance of the earth
from the sun, 182; Velocity of planetary light as com-
pared with that of sound, 183; Humboldt’s remarks
on lunar distances, 185 ; Comparisons of the light of
sun and moon, 185; Michel and Euler on the same
subject, 186 ; Arago’s observations on the polariscope,
187; Uses of the polariscope, 188, 189; Sir David
Brewster on polarized light, 181-192; State of the
barometer at different phases of the moon, 193-195 3
The influence of the moon on the weather, 198.

 

PART III.

ON THE ALLEGED INFLUENCE OF THE
MOON ON THE INSANE.

“ Lucid intervals,” origin of the term, 199; Legal definition -
of the word “lunatic,” 199; Meaning ofthe phrase “lucid
interval,” 200, 201; M. D’Aguesseau’s analysis of the
term, 202, 203; Dramatic and poetic references to the
influence of the moon on the mind and passions, 204-
207 ; The phenomenon of periodicity viewed in relation
to insanity, 208; Illustrations on the subject from the
writings of Pinel, 208-210; Periodical attacks of
xiv Contents.

 

drunken madness, or dipsomania, 210, 211; The
periodicity expiained independently of lunar influence,
212, 213; Pinel’s explanation of the phenomenon,
213, 214; Bouillon and Saugage’s cases of lunar in-
fluence, 215; Celsus on the influence of the moon,
215, 216; Dr. Haslam’s opinion on the same subject,
217; Dr. Woodward on the influence of the moon
on the insane, 219-221; Effects of sol-lunar influence
on maniacal paroxysms, 222; Effect of the eclipse of
the sun in 1806 on the lunatics in Bethlehem Hospital,
223, 224; Daquin on the influence of the moon on
the insane, 225-228; Guislain’s opinion on the same
subject, 228; Effect of meteorological phenomena on
the insane, 229; Sleeplessness and agitation noticed
among the insane at the full of the moon, 230; Effect
of light and darkness on the illusions and hallucinations
of the insane, 231, 232; Influence of different colours
on the brain and mind, 234.

 

PART IV.
HYGIENE OF LIGHT.

Effect of the absence of light on the blood, heart, brain,
and muscles, 235-237; Sir David Brewster on the
blessings of light, 237; On the construction of build-
ings with the view to the admission of the maximum
degree of light, 237, 238; On’ the unhealthily-housed
populations of New York and Bethnal-green, 238, 239 ;
Contents. XV

 

The effect of the absence of light on the poor living in
courts, narrow streets, &c., 240; Sir David Brewster’s
suggestion for remedying this evil, 240, 241; On the
physical condition of the working classes of Edinburgh,
241, 242; Sir David Brewster on the value of light as
a hygienic agent to the poor, 242-246 ; Scorbutic affec-
tions caused by the absence of light, 246, 247; On the
exclusion of light from young infants and children, 247 ;
Rules for the treatment of children with reference to
their being exposed to the influence of light, 248, 249 ;
Dr. Andrew W ynter’s opinion on the subject, 249, 2513
Humboldt on the robust health of the Mexicans, Peru-
vians, Indians, &c., caused by their being freely exposed
to light, 251, 252; Dr. Bryson on the unhealthy condi-
tion of seamen confined in dark holds of ships, &c.,
2523; Judicious hygienic arrangements made for the
patients of the hospital of St. John, at Brussels, 255 ;
Importance of light to persons suffering from disease,
255,250; Florence Nightingale on the construction of
public hospitals, 257-259; The effect of darkness on
disease as observed in the hospital at St. Petersburg, 260 ;
Singular case of the same kind related by Baron
Dupuytren, 260, 261 ; Dr. Hammond on the impor-
tance of light to the sick, 262; The virulence of
cholera increased by the absence of light, 262, 2633
Injury caused by glaring light and sudden transition
from darkness to light, 263, 264; On disorders of the
vision caused by a prolonged exposure to intense light,
265-2723; The effect of snow and ice upon the eyes of
sheep, 272; Ditto on the Greek soldiers, as related by
Xvi Contents.

 

Xenophon, 273; The effect of the glare of brilliantly-
lighted rooms on the organ of vision, 273; Injuries
resulting to the eyes from artificial light, 274 ; Medical
instructions for the regulation of the different colours
of light, 275 ; On the probable effect of the vapour of
iron found in the sunlight by the spectrum on the
health of the body, 276-278 ; On the introduction of
metallic poisons into the body through the skin, 278.

APPENDIX . . « + » + + « « « Pages 279-301
ON

THE INFLUENCE OF LIGHT.

 

PART I.—THE SOLAR BEAM.

 

“Gop said, Let there be light: and there
was light.”* ‘These were the sublime words
of the Almighty, when, by an act of
Sovereign power, He willed into existence
“two great lights, the greater light to rule
the day, the lesser light to rule the night.”
The object of the following essay is to
consider in a philosophical, and I hope a

reverential spirit, the physiological and

 

* VN TD) WN oP —“ Be light! and light was.” —
Gen i. 3.
I
2 On the Sanatory and

 

pathological—the healthful and morbid—
effects upon the animal and vegetable king-
dom of that principle .which, at the fiat of
the wise and beneficent Creator, radiated
in all its original glory from the Heavenly
luminary, and when seen by Him was em-
phatically pronounced to be ‘‘ good.”

This subject has two aspects : of the life-
giving and benign effects of light I purpose
fully to speak. It is also my intention to
consider the baneful influences of the solar
beam and lunar ray, upon the vegetable
creation, vital force, physical and mental
development.

When speaking of the unalloyed hap-
piness in store for man in a purer, higher,
nobler, and beatified state of existence, an
inspired prophet places prominently in ad-

vance among the great blessings that will
Physiological Influence of Light. 3

 

be associated with our exemption from the
pernicious operation of those physical agents
which in this world are known (under cer-
tain conditions) to be obnoxious to our well-
being, the promise, that ‘‘the sun shall not
smite thee by day nor the moon by night.”*

After so solemn a declaration, need I
hesitate in approaching the consideration of
not only the sanatory but the morbid in-
fluence of the sun upon the human race ;
and need I offer any apology for analyti-
cally investigating the abnormal as well as
the zormal effects of lunar light on the
flora of creation, the material and mental
organization of man?

As it would be irrelevant for me to enter
into the discussion of the varied theories of

light that have been propounded, I proceed

 

* Psalm cxxi. 6.

B 2
4 On the Sanatory and-

 

at.once in the first place to.establish how
essential’ the solar: beam-is to the. preserva-
tion, of ‘the bodily:and: mental health, pro-
motion of longevity, beauty: of the’ physical:
form, serenity and’integrity of the mind.*
‘There can~be-no persistent vitality: nor -
healthfully developed bodily structure with-
out light. If-it. were. possible for a human
being to be placed: during.the natural term:

of his existence, in a position of : perfect:

 

*® From the earliest periods i in the history of Medicine,
solar heat was considered: to prolong human life. : “ Old
men,” says aici “are double their age in winter,
and younger in summer.” = In order to obtain the full
advantages of the light and heat of the sun, the ancients
had terraces built on the tops of their houses called
solaria, where they took what was termed their “ solar-
air-bath.” Speaking of his uncle, Pliny observes, “ Post
cibum estate si quid otii, jacebat in sole.” - Asthe sun rose,
disease, according to the views of the ancients, declined..
“Levato sole levatur morbus,” was a recognised medical
axiom in former times.
Physiological Influence of Light. 5

 

darkness, the physical tissues and. mental '
‘faculties would undergo serious modifica-
tions and degenerations.

Where ‘light is not permitted to per- |
meate, there are found, in the highest state
of manifestation, bodily deformities, intel-
lectual . deterioration,- crime, ‘disease, early
and often sudden death. A’ material, as
well as a moral and mental, etiolation or
‘blanching occurs when ‘the vital stimulus of
light is withdrawn. :

A vast body of evidence conclusively es-
tablishes the inestimable value of this agent
to the health of both body ‘and ‘mind.
Compare the bright, ruddy, happy faces
and buoyant spirits of those who reside in
the country and work in the open fields, and
upon whom the sun is generally shining,

with the pale phlegmatic faces, emaciated,
6 On the Sanatory and

 

stunted forms and nervous depression of
those whose vocation in life deprives them
of the health-giving and beneficial influence
of light. In order properly to test the
question, place side by side the robust,
sunny, rosy-cheeked and happy lass or lad
of the village with the pallid, sickly, melan-
choly girl or boy residing in one of our
‘manufacturing towns, who are pursuing
their vocation in a room or hermetically
sealed building, where darkness has obtained
an undue supremacy. Notice the difference
between the two classes of human beings!
It may be enunciated as an indisputable
fact, that all who live and pursue their
calling in situations where the minimum
degree of light is permitted to penetrate,
suffer seriously in bodily and mental health.

These pathological phenomena are prin-
Physiological Influence of Light. 7

 

cipally observed among those confined in —
dark mines and collieries, badly-constructed
houses containing but few windows, holds
of ships, factories, and in persons incar-
cerated in dungeons and buried for a con-
siderable length of time in prisons, as well
as the denizens of narrow streets, crowded
alleys, confined courts, garrets, or cellars,
where the blessed light of the sun has a
difficulty in penetrating.*

The total exclusion of the sun’s beams

 

29

* “T never shall forget,” says Dr, Hammond, “ the ap-
pearance presented by the sick of a regiment I inspected
about a year since in Western Virginia. They were
crowded into a small room, from which the light was
shut out by blinds of india-rubber cloth. Pale and ex-
sanguined ghost-like looking forms, they seemed to be
scarcely mortal. Convalescence was almost impossible ;
and doubtless many of them died, who, had they been
subjected to the operation of the simplest laws of nature,
would have recovered.” —“ Treatise on Hygiene,” Phila-

delphia, 1863, p. 209.
8 On the Sanatory and

 

from the. body induces the severer types of
chlorosis (green sickness) and other anemic
conditions depending upon an impoverished
and disordered state of the blood. Under
these circumstances, the face assumes a
death-like paleness, the membranes of
the eyes become bloodless, and the skin
shrunken and turned into a white greasy
waxy colour.

Associated with these symptoms there are
emaciation, muscular debility and degenera-
tion, oedematous conditions, dropsical effu-
sion, softening of the bones (‘ mollities
ossium”), general nervous excitability, mor-
bid irritability of the heart, loss of appetite,
tendency to syncope and hemorrhages,
consumption, physical deformity, stunted
growth, mental impairment and imbecility,

coupled with premature old age. The off-
Physiological Influence of Light. 9

 

spring of those so unhappily trained are
often deformed, weak, and puny, and are
disposed to scrofulous affections.

The wretchedly unhealthy condition of.
that portion of the working population of
this country who live and work in darkness
was satisfactorily proved at the Parliamentary
inquiry which took place on this subject
many years ago.*

Similar consequences are observed in all
those who labour by night and sleep by
day; such as bakers, police-constables,
compositors connected with the daily press,
whose occupation necessitates their employ-

ment during the greater part of the night.

 

* The light in the pent-up dwellings of large towns,
inhabited by the poor, is polarized light, it being always
only a reflected solar beam. The effect of the light and
atmosphere contained in such dwellings on the mind as
well as the body is as previously stated.
10 On the Sanatory and

 

The data collected by foreign writers
fully substantiate this truth. I refer par-
ticularly to the investigations made and
facts recorded in reference to the health of
the miners of Belgium, Hungary, and
France, as published by Drs. Ozanam,
Hoffinger, Hallé, and M. Dupectiaux.*
According to the observations of these dis-

tinguished authorities, the morbid changes

 

*T extract the following from the Geelong Advertiser.
It must be taken quantum valeat.— It is a curious fact,
connected with deep mining, that from the hours of
twelve at night till three in the morning the disturbing
influence in the bowels of the earth obtains increased
activity. At that time it is observed by miners that
water falls from places where none is observable during
the day. The volume in the wheel is perceptibly in-
creased, the atmosphere is charged with gases which often
prevent the lights from burning, and small particles of
earth and rock are observed to fall from the tops of the
drives. Whether this phenomenon is to be attributed
to the diurnal motion of the earth or other causes, it is
worthy of the attention of the curious.”
Physiological Influence of Light. #1

 

on body and mind which are consequent
upon the exclusion of light are singularly
significant and remarkable.

In numerous instances the general health
becomes vitiated, and the function of nu-
trition seriously interfered with. Not only
are specific diseases generated, but physical
as well as mental development arrested, In
many young girls and boys who are at an
early age consigned to a life of darkness in
mines, or in other places, puberty is either
never attained or is greatly retarded ; in
fact, the mind as well as body becomes
impaired in its growth, as the effect of
light being excluded from the human’
organism.

No doubt the damaged health of those
who are constantly working in dark mines
and collieries is not altogether attributable

to want of light, although observing and
12 On the Sanatory and

 

practical men have assigned this as one of
the principal reasons for the physical and
mental ailments to which this section of the
labouring classes is liable.

Fourcault affirms that .where life is pro-
longed: perhaps to the average term, the
evil effects of the want of. light are seen in
the stunted forms and: general ‘deteriora-
tion of the human race. It appears that
‘the inhabitants of. the arrondissement of
| Chimay, in Belgium, three thousand in
| number, are engaged ‘partly as ‘coal-miners
and partly as field-labourers.. The latter are
‘robust, and readily. supply their proper num-
! ber of recruits to the army ; while among the
. miners it is in most years impossible to find
a man who is not ineligible from bodily de-

formity or arrest of physical development.*

 

* Causes Generales des Maladies Chroniques. Paris,
1844+
Physiological Influence of Light. 13

 

In association with the want of light
should be considered the deleterious effects
of dampness, deficient nourishment, impure
air, over work, anxiety of mind, the inhala-
tion of noxious and poisonous gases, fine
dust, &c., upon:the general and specific
health of those exposed to the injurious
operation of these physical agents.

With these prefatory remarks I open the
subject. of light in its physiological and
morbid relations. I would, however, pre-
mise that it is not my object to discuss the
special astronomical phenomena of the solar
ray ; neither.do I propose to weigh the
relative value of the corpuscula, undulatory,
or other theories of light. I desire to
restrict my remarks to the direct influence
of this agent on vital manifestations, and to

refer to some of the more remarkable facts
14 On the Sanatory and

 

illustrative of the effects of the exclusion of
light on the bodily and mental health, and
on animal and vegetable life.

In the first place, I have to point out the
influence of light on the vital and physical
organization of different animals. Dr.
Edwards instituted a number of interesting
experiments with the view of ascertaining
the effect of light, independently of heat,
upon the structure and growth of animals,
particularly between the interval of concep-
tion, fecundation, and adult age.*

This physiologist placed some frog’s
spawn in water. The vessel containing it
was made impervious to light by being
covered with dark paper. A similar

experiment was tried in another vessel

 

* “On the Influence of Physical Agents on Life.” By
W. F. Edwards, M.D., F.R.S., 1832.
Physiological Influence of Light. Ty

 

\

which was transparent. The two vessels
were exposed to the same degree of
temperature, but the transparent one was
placed under the influence of the sun’s
rays. The eggs were developed in succes-
sion; of those in the dark none did well.
Unequivocal indications were observed of
the transformation of the embryo in a few
of the eggs. Dr. Edwards’ experiments
were confined to the batrachian family.
The absence of light did not necessarily
interfere with the development of these
reptiles. ‘Two tadpoles, out of twelve con-
fined in a tin box, pierced with small holes
for the change of water, and placed at the
depth of several feet in the Seine, under-

went the regular change of organic form.*

 

*“T have,” says Dr. Hammond, “ often repeated Dr.
Edwards’ experiments, and always with analogous results.
3
i

16 On the Sanatory and

 

It appears that the transformation of two
of the animals was retarded by the absence
of light. For the purpose of fully settling
this question, tadpoles were confined in two
large vessels, each containing ten litres of
water, both capable of admitting light ; one
of glass, but with a partition close to the
water, to prevent atmospheric respiration ;
the other open, in order to allow the
animals an opportunity of rising to the
surface, and inflating the lungs. Those who
were deprived of fresh air were later in
transforming themselves than the others,
but this delay was so short that the inter-

ference with the respiration appeared to be

 

 

On one occasion I prevented for 125 days the develop-
ment of a tadpole, by confining it in a vessel to which
the rays of light had no access. On placing it in a recep.
tacle open to light, the transformation was at once com-
menced, and was effected in fifteen days.”
Physiological Influence of Light. 17

 

too slight to produce any effect on vital
development. It was clear that the exclu-
sion of the light had a serious influence on
the transformation of the tadpoles plunged
in water.

Sir Humphrey Davy refers in one of his
most charming works to the arrest of de-
velopment that takes place in the Proteus
Anguinus consequent upon its exclusion
from light.*

In the grotto of the Madea. Re says,
at Adelsburg, in Illyria, many hundred feet
‘below the surface, are seen creatures like
slender fish, moving in the mud below the
water. These aré the protei: the animal
is of a fleshy whiteness, and transparent in

its natural state, but when exposed to light

 

* “Salmonia; or Consolations in Travel.”

Cc
18 On the Sanatory and

 

its skin gradually becomes of a darker
colour, and at last: gains an olive tint.
. Being abundantly furnished with teeth, it
is inferred that the animal is one of prey,
yet in its confined state it has never been
known to eat, and it has been kept alive for
many years by ‘occasionally changing the
water in which it was placed. They have
also been found at a place thirty miles dis-
‘tant from the cavern, thrown up by water
‘from some subterraneous cavity. In dry
seasons the protei are very seldom seen in
the lake of the Madalena, but after great
rains they are often abundant. Their
natural residence is an extensive subter-
raneous lake, from which in great floods
they are sometimes forced through the
crevices of the rocks into the place where

they are found.
Physiological Influence of Light. 19

 

These singular creatures Sir H. Davy
affirms have no organs of vision, but in
their place are two small dots which occupy
the position of eyes. It has not been ascer-
tained that they have any power of percep-
tion. The entire absence of colour, and
the imperfect development of their organs,
in at least their intermediate condition,
between those of a reptile and a fish, seem
to be the result of the absence of light.

Their exclusion from the solar beam is
well known to produce organic alterations
in the visual organs of animals, such as
atrophy of the optic nerve, or those por-
tions of the brain (the corpora quadri-
gemina) more immediately associated with
the sight. It is supposed that the blindness
observed among fish found in the dark
caves of the Tyrol and Kentucky arises from

ca
20 On the Sanatory and

 

the arrest in the development of the eyes as
the result of a constant deprivation of light.
In elaborating this subject I have to con-
sider the effect of solar light and heat in
discolouring the skin of different races of
men by producing minute injections of. the
capillary vessels on the surface of the body
and developing what physiologists term the
black pigment cells. These peculiarities,
however,’ are: not confined. to shades of
colour, degrees. of physical development,
stature, and power, but extend to the
animal passions as well as mental energy.
“Ts not,” asks Mr. Hunt, “ the short-lived
beauty of the oriental women to be attri-
buted to the influence of that sun
: © Shining on, shining on, by no shadow, made tender,”
which is known to give all the grandeur to.

the vegetable world of the east ?”
Physiological Influence of Light. 21

 

Black, brown, and copper-coloured skins
are observed among those who reside in
tropical climates in proportion to the inten-
sity of the solar light, and the degree to
which the body is exposed to its influence.

This discolouration of the.skin is not,
however, perceived among. those who live
in temperate and cold regions. ~

As we approach nearer to the pole the
skin assumes a browner cast.

This is evidenced among the Laplanders,
Esquimaux, and Greenlanders. In the arctic
regions there cannot be said to exist, in the
right acceptation of the term, any night.
Here a constant light prevails, if not from
the sun yet reflected from the snow and ice
or emitted by the aurora borealis. According
to Captain Ross the natives of these climes

suffer from the effects of intense light, and
22 On the Sanatory and

 

are subject to inflammation of the eyes and
blindness caused by cataract and paralysis of
the optic nerve. These diseases are not
confined to-the natives.

Even among the African negroes the
skin is observed to lose its intense black
colour, particularly in those whose occupa-
tion enables them to live for many months
of the year in the shades of the forest where
the sun’s rays, owing to the thickness of
the foliage and the size of the trees are
unable to penetrate.

It is said that the black colour of the
negro race is less permanent: in its character
than the red or olive tints. The children
of olive and copper-coloured parents, ac-
cording to the authority of Dr. Mason
Good, exhibit the parental hue from the
_ moment of birth, but in those of blacks it
Physiological Influence of Light. 23

 

is occasionally six, eight, or ten months;
before the dark pigment is fully secreted.
It frequently happens that the black pig-
ment cells are not matured even among.
negroes. Hence are observed in this .
race of men children with white skins or
bodies interspersed with only interrupted
lines of black patches. These are called
“spotted negroes.” “The black pigment has
been known during attacks of severe illness
to be entirely absorbed, and a white pigment
cell developed in its place, thus affording
a remarkable illustration of a dlack person
being suddenly bleached intoa white man! In
the ‘‘ Transactions of the Royal Society” is
an account of a woman whose left shoulder,
arm, and hand were as black as an African
negro’s, whilst all the rest of the skin was

perfectly white. This anomalous condition
24, On the Sanatory and

 

was said to have arisen from her mother
having during pregnancy ee her foot upon
a lobster !

No doubt the coarseness of the wool
of animals, and hair of human beings, as
well as the amount of colour developed in
their skin, is, to a degree, caused by
the nature’ of their food. Oils and
spirits are well known to disorder the liver,
and those who indulge to excess in these
articles of diet have generally an excess of
bile circulating in the blood. Intemperate
persons Hees vinous potations have
a sallow and olive-hued complexion. The
dark and dingy colour of the pigmy people,
who live in high northern latitudes, arises
principally from the fish and oils of a rancid
and often offensive character upon which

they mainly subsist. This kind of diet is
Physiological Influence of Light. 25

 

believed not only to affect the colour of the
skin, but to cause a diminution in the
stature of this race, in consequence of
their food being difficult of assimilation
and defective in nutrition.

Dr. Mason Good affirms that swine or
other animals fed on. madder root, or
gallium-verum (“ yellow-ladies’-bedstraw ”),
have the bones tinged of a deep red or
yellow colour. M. Huber, the celebrated
naturalist of Lausanne, was able, by the
quality of the food given, to convert what
is commonly, but improperly, called a
neuter into a queen bee. .

Trinocq, when speaking of the effects of |
light on the colour: of the body, affirms,
that among the Red Indians the skin that
is not exposed to the influence of the sun’s ©

|
rays is quite white; in other words, the |
26 On the Sanatory and

 

face, neck, and hands are dark, whilst the
limbs. which are covered by. clothing are of
an entirely different hue.

The same phenomena are observed in all
tropical climates. The white colour of
animals inhabiting the polar regions is attri-
butable to the absence of intense sunlight.

The changes referred to are clearly trace-
able to the direct influence.of the sun, and
are not exclusively caused: by.a high degree
of temperature. Persons who live in hot
and tropical climates and whose occupation
exposes them to great heat apart from the
solar beam coming into immediate contact
with the body, do not suffer from any

marked discolouration of the skin.*

 

* Gardeners who are occupied for the greater part of
the day in hot-houses, exposed to intense heat, are not
generally tanned.
Physiological Influence of Light. 297

 

Among the negroes of the torrid zone,
Albinos are seen; but these become scarce
near the equator. It is a commonly ob-
served fact that among fish, those parts of
the body not exposed to the free action
of light become of a pale hue, and are
sometimes quite white. This fact is no-
ticed among a certain species of flat-fish.
The axolotus pisciformis, syren lacertina,
and the ¢riton sittatus (fish that live at
great sea depths, and are consequently ex-
cluded from the light), have transparent ,
bodies.

Certain animals, whose natural hue is’
white, if bred and brought up in darkness, .
become completely altered in texture and
colour. The cockroach, in its normal state,
is intensely black. If this insect be taken at

an early stage of its existence and carefully
28 On the Sanatory and

 

reared in darkness, instead of assuming an
inky hue when it arrives at full growth,
it becomes nearly white. .

The larve of most insects that burrow
in the cavities of the earth, of plants, or of
animals, are: white from the same cause.
When confined under glasses that admit the

‘influence of solar light, they exchange their

-whiteness for a brownish hue. It is said
that Asiatic and African women confined to
the walls of their seraglios and ‘secluded

‘from the sun are as white as Europeans.

It is of deep philosophical interest to
consider in relation to the present subject,
not only the effect of climate, meteorolo-
gical changes, combined with the influence
of varied degrees of. light upon. the
general health, great. nervous centres,

and muscular development, but the modi-
Physiological Influence of Light. 29

 

fications which the physical force under-
goes from the same causes as far as the
growth, stature, and longevity of the inhabi-
tants of various countries are concerned.

Investigations have been made for the
purpose of ascertaining the effect of various
kinds of climate upon the stature of dif-
ferent nations. It has: been satisfactorily |
established that persons placed under the
same solar influences have not the same
stature; and, reciprocally the same stature is
found among people placed relatively to the
same influence under very different condi-.
tions. The subjoined facts in illustration
of this subject are quoted from M. Sanson-
Alphonse’s thesis on the influence of light:
and the development of health.

In the southern hemisphere the Papoes
of Vaigion, at 1° from the Equator, the
30 On the Sanatory and

 

Vankoros at 12°, the Bushmen mountaineers
at 30° (an Ethiopic race), who receive
the rays of the sun with great intensity
of light and heat, have a stature of
5 ft. 1 in., very little above that of people
who dwell in the northern hemisphere, the
Kamschatdales, the Tartars and the Esqui-
maux (a Mongol race), in latitude 60° to 70°
north, where only the oblique rays of the
sun reach them, people of whom the stature
is 4 ft. 3 in. to 4 ft. 7 in.

High stature is met with equally in very
different latitudes; thus in the southern:
hemisphere we find 5 ft. 10 in. to be the mean
height of the Caribs (an American race),
who inhabit regions situate between 1° and
8°, the natives of the “Iles Marquises”
at 10°, the inhabitants of the Navigator’s

Islands at. 14°. People whose countries
Physiological Influence of Light. 31

 

are very near each other differ considerably
in stature. Thus the Patagonians, of
whom the mean height is 5 ft. 10 in., are
only separated by the narrow straits of
Magellan from the inhabitants of Terra
del Fuego, of whom the stature is only
4 ft. 3 in.; thus the people of Sweden
and Finland join the Laplanders ; and the
New Hebrides, so near the Navigator’s
Islands, whose population have a very high
stature, are inhabited by a short and badly
made race.

People of the same stature dwell either
in maritime regions on the continents up to
a level sufficiently elevated above the sea.
Temperature has certainly more influence
upon stature than light.

The inhabitants of very cold regions,

whether situated near the poles or on the
32 On the Sanatory and

 

tops of mountains covered with snow, are
small.

Increase of stoutness is observed among
people who inhabit regions far from the
‘equator, and especially those in which there
is much moisture. It is there especially that
the marks of a lymphatic temperament are
apparent. Under the same zones, but on
more elevated plains, are seen men who
combine the greatest bodily development
with the maximum of muscular power.
They are of a sanguine temperament.

In ascending further above the level of
the sea and up to the regions of snow, the
men are small, but thick set.

As we approach the equator and elevated
regions the inhabitants are withered, with the
muscular system very moderately developed,

but endowed relatively with considerable
Physiological Influence of Light. 33

 

energy. Such are especially the Arabs.
Their constitutions present the character of
a nervo-bilious temperament.

Although the free life of savages may
be favourable to the regular development
of their forms, they do not acquire under
the influence of climate any remarkable
muscular power.

The natives of Timor, New Holland,
and Tasmania are very inferior to the
English sailors in trials of strength
(Péron).

The natives of America show the same!
inferiority of physical force. The negro’
race, who bear in the highest degree the

_impress of the effects of light, always ap-
pear, although individually not the most
active, the best suited for continued labour
under the light and heat of the sun.

D
34 On the Sanatory and

 

Within the limits of climate inhabited by
the negro race they appear to enjoy a very
strong constitution. The same observation
applies to the Arabs.

The inhabitants of high latitudes consume
much more food than those who dwell in
intertropical regions, and have more corpo-
real development. The superior muscular
force with which they are endowed is partly
explained by this great consumption of
food, by their habits of labour, and the
consequent increase in the volume of their
muscles.

Growth is more rapid in equatorial re-
gions, and puberty is reached earlier; but
the age for marriage ceases sooner. ‘There
are more examples of longevity among
the people of the north than among those

of the torrid zone and more southern
Physiological Influence of Light. 35

 

countries ; but some particular facts would
lead me to believe that these people would
also attain a very advanced age.*

It is not my intention to consider the °
ethnological view of this subject. That
the influence of solar heat materially modi-
fies the national character cannot for a
moment be doubted. Like plants and
animals man, the highest order of intelli-
gence obeys the laws regulating the world’s
zonal arrangements. According to climate,
degrees of temperature, &c., the human
race becomes passive, savage, doltish, or
intelligent. These affect his physiognomy,
dialect, and habits of life as well as his

mode of subsistence. When speaking of

 

* “De Vinfluence de la Lumiére sur le développe-
ment et la Sante.” Par M. Sanson-Alphonse. (Agrégé
de la Faculte de Médecine de Paris). Paris, 1852.

D2
36 On the Sanatory and

 

influences of climate as well as local positions

upon the physical and mental organization,

_ a recent writer observes, after glancing at

| man’s geographical position, —“ Here, active,

intelligent, and progressive; there, slug-

-gish, dull, and stationary: here, enjoying

the highest amenities of civilization ; there,
grovelling in a condition little elevated
above the brutes by which they are sur-
rounded. And not merely do they differ
in intellectual qualities, but in physical
organization, in mien and stature, in form
of head and expression of face, in colour of
skin, in strength and endurance, and, in
fine, in all those purely bodily qualities by
which one species of animal is distinguished

from another.” *

 

* @ Advanced State of Physical Geography,” by D.
Page. London, 1864.
Physiological Influence of Light. 37

 

I have now to refer to the influence of |
deep sea-water on vegetable and animal life
(“ flora” and “ fauna”’), so far as its stratum,
illustrates the effect of the exclusion of light
(under these circumstances) in modifying |
vital force, and in interfering with or arrest-
ing physical development.

It will, however, be necessary to consider
preliminarily in connexion with this subject
two important and interesting questions :
ist. What, according to well-ascertained
data, is the depth of the sea in various
portions of the globe? and. To what
extent solar light is known to penetrate the
ocean?

ist. It has been found, owing to the
irregularity in the form of its basin and a
variety of other causes, impossible to ascer-

tain with any degree of scientific exactness
38 On the Sanatory and

 

the mean depth of the ocean. In consequence
of the character of the tidal waves and cer-
_ tain undulatory movements which occur in
deep waters, four miles has been said by

some eminent physicists to be the maximum

extent to which the plummet has descended.*

 

* “The mean elevation of all the land-continents, and
islands, mountains, and plains has been estimated by Hum-
boldt at somewhat less than rooo feet; and the mean
depth of the ocean has been calculated by Laplace, from
tidal waves and kindred phenomena, to be at least 21,000
feet, or about four English miles. We know, however,
that a very large proportion of the ocean is comparatively
shallow, and not a tithe of this depth; and therefore, to
make up the mean, some other portions must be propor-
tionally deeper, and to the extent it may be of eight or
ten miles. Indeed, soundings (nodoubt open to question)
have been made in the South Atlantic, both by British and
American navigators, varying from 27,000 to 46,000 feet ;
and soundings, perfectly reliable, have been taken in the
North Atlantic, off the bank of Newfoundland, to the
depth of 25,000 feet ; while from calculations on the velo-
city of tidal waves, which are found to proceed according
Physiological Influence of Light. 39

 

Reliable authorities, however, affirm that
oceanic soundings have been taken at the
depth of five, eight, and even to the extent
of ten miles. There are numerous instances!
where twenty, thirty, forty, or even fifty
thousand feet of line have been played out
without giving distinct evidence of its
having reached the bottom of the sea. I
state this on the authority of Sir J.
Herschel. The average depth of the
Pacific (in consequence of its being abun-
dantly bestrewn with islands), is said to be
less than that of the Atlantic Ocean.

In 27° 26’ S. latitude and 170° 29’ W.
longitude, Sir James Rosse found the depth

 

to the depth of the channel, it has been estimated that the
extreme depths of the same ocean are about 50,000 feet,
or more than nine miles.”—(Advanced Text Book of
Physical Geography, by David Page, F.R.S.E.)
40 On the Sanatory and

 

of the sea to be 14,450 feet. About 450
miles west of the Cape of Good Hope, it
was 16,062 feet, or 323 feet more than the
height of Mont Blanc ; and goo miles from
St. Helena, a line of 27,000 feet did not
reach the bottom of the sea, a depth equal
to the height of some of the most elevated
peaks of the Himalaya. It is, however, sup-
posed that there are many parts of the ocean
still deeper. Speaking in general terms, the
depth of the Atlantic averages from three
to four miles. The “ Telegraphic Plateau,”
stretching from Cape Clear to Cape Race, a
distance of 1640 miles, is only about 11,000
or 12,000 feet in depth; the greater
depths (from 4 to 6 miles) have been
determined in the Indian and Southern
Oceans. The Arctic is of moderate depth,

and characterized by great irregularity and
Physiological Influence of Light. 41

 

diversity. The greatest ascertained depth
in the Mediterranean is about 13,000 feet ;
in the Red Sea, 6300 feet; Baltic, 840
feet ; Caribbean Sea, 14,000 feet; and in
the Gulf of Mexico, about 8000 feet.

and, The depth at which solar light ‘ee
believed to permeate the ocean is calculated
to be about 7oo feet.* The distance to
which the eye can penetrate the sea depends |
principally upon its transparency.f

In experimentalizing as to the depth of
the ocean, it has been suggested that inde-

 

* In connexion with this subject it is important to
notice the fact referred to by Sir J. Herschel, viz., that the
light which penetrates to a great depth in the sea, is very
different in its photo-chemical qualities from the solar
light of the surface. Again, in calculating the degree to
which the solar beam is seen to pierce the sea it will be
necessary to bear in mind the effect of various media
through which light passes on the refraction of its rays.

+ David Page.
42 On the Sanatory and

 

pendently of considering the transparency
of the water, we should test its phosphor-
escence, the face of the sky, whether clear or
cloudy ; the state of the sea, whether rough
or smooth ; the condition of the weather,
whether calm or windy.

The heat of the water should also be tried,
at various depths and hours of night and
day, in order to ascertain not only the maxi-
mum temperature and average depth of the
warmest stratum in the day, but the differ-
ence in its temperature and position by day

and by night.* These observations will

 

* Accurate calculations have been made as to the tem-
perature of the ocean. The results obtained clearly establish
that the lowest degrees of temperature are obtainable on
the surface of the water. About ten feet below the sur-
face the thermometer rises several degrees. Ninety degrees
is said by Mr. Agassiz (son of Professor Agassiz) to be
the ‘highest temperature he has known the ocean to
Physiological Influence of Light. 43

 

afford the data, also, for computing the
amount of solar heat that penetrates the
bosom of the sea, as well as the amount
that is radiated thence again. They will
reveal to us knowledge concerning its acti-.
nometry in other aspects. We shall learn
how absorption by, as well as radiation
from, the under strata is affected by a
rough sea, as when the waves are leaping
and tossing their white caps; and how by
its glassy surface, as when the winds are
hushed and the sea smooth.

Mrs. Somerville asserts, that in some:
parts of the Arctic Sea, shells are dis-
tinctly seen as low down as 80 fathoms ;
and among the West Indian Islands, at the

same depth of water the bed of the sea is as

 

attain. At very great depths of the ocean a uniform tem-
perature of about 393 degrees has been found. (D. Page.) _
44 On the Sanatory and

 

clear as if seen in air. At this great depth
shells, corals, and seaweeds of every hue
display to the eye of the observer the beau-
tiful prismatic tints of the rainbow.
' In connexion with this subject it is ot
“interest to consider the varied colour of the
_sea in different parts of the globe, for upon
‘this principally depends the depth at which
‘the sight can reach. Assuming as a well-
established fact that the waters of the ocean
derive their colour from animalcules of the
infusorial kind vegetable substances and
minute particles of matter, it may be affirmed
as facts recorded by all writers on Physical
Geography, that the sea is white in the
Gulf of Guinea, black around the Maldives,
vermilion off California (caused by the red
colour of the infusoria it contains), and

green in the Persian Gulf.
Physiological Influence of Light. 45

 

In the Arctic Sea the colour of the water
undergoes rapid transitions from ultrama-
rine to olive green ; from purity to opacity.
The green colour is said to be produced by
myriads of minute insects which devour one
another and are a prey to the whale. The
varied tints of the ocean in its shallow parts
depend to a degree upon the sea bed over
which it passes. A bottom of chalk or
white sand, produces an apple green colour ;
over yellow sand, a dark green; brown or
black over dark ground; and grey over
brown mud.*

Physicists have instituted a series of in-_
teresting experiments with a view of ascer-
taining by carefully executed deep sea

soundings, the maximum depth at which

 

* Physical Geography.
46 On the Sanatory and

 

various species of animals (marine molusca
and those belonging to the intervertebrate
class), as well as plants, are capable of
sustaining life.

With this object Professor Forbes was
engaged for a period of eighteen months in
the AZgean Sea, and on the coast of Asia
Minor, in sea bottom explorations by means
of the dredge. He has demonstrated by
actual observation that below the depth of
35 fathoms, the number of animals di-
minishes as we descend, until at the depth
of about 200 fathoms the ‘number of tes-
tacea was found to be only eight, and a
zero in the distribution of animal life was
indicated at probably about 300 fathoms.
Green fuci was not found below 55 fathoms,
and millepoza not deeper than tos fathoms.

Similar phenomena are observed in some
Physiological Influence of Light. 47

 

portions of the British Channel, viz., the
south coast of Cornwall.*
Professor Bailey of West Point, an emi-

nent American geographer, naturalist, and

 

* The following is the classification of marine animals
according to the zones of depth at which they live: —

ist. Littoral found between high and low water marks,
a species capable of living in air as well as water, such as
crustaceous animals, crabs, testacea shell-less animals which
close themselves up or seal themselves hermetically on the
rocks and remain dormant during the recess of the water.
Among these are found the petallas mytilli and littorinas
purpuras, and among the zoophytes the common sea
anemone.

and. The circumlittoral zone existing at 1g fathoms,

3rd, The median zone from 1g to go fathoms,

4th. The infra-median ; and

5th, the abyssal zone; the former from soto 100 fathoms,
the latter from thence to the lowest depths at which life is
possible.

Sir John Herschel says, when referring to this subject,
each of these zones is characterized by species which
belong to no other, and each passes into the other by the

intermixture of species common to several.
48 On the Sanatory and

 

microscopist, says in a letter to a brother phi-
losopher; ‘the bottom of the ocean at the
depth of more than 2 miles I hardly hoped
ever to have a chance of examining; but,
thanks to Brooke’s contrivance, we have it
(the deep sea deposit) clean and free from
grease, so that it can at once be put under
the microscope. I was delighted to find
that all these deep soundings are filled with
microscopic shells ; not a particle of sand or
gravel exists in them. They are chiefly
made up of perfect little calcareous shells
(“ foraminifera”), and contain also a num-
ber of silicious shells (‘‘ diatomacee”). It
is not probable that these animals lived at
the depths where these shells are found, but
I rather think that they inhabit the waters
near the surface, and when they die their

shells settle at the bottom.” Lieut. Brooke,
Physiological Influence of Light. 49

 

of the North Pacific Exploring Expedition,
procured specimens in the coral sea from
the bottom at the depth of 2150 fathoms.
These soundings yielded representatives of
most of the great groups of microscopic
organisms. Professor Ehrenberg, of Berlin,
found the deep sea specimens to consist
principally of calcareous carapaces, filled
with soft pulp or fleshy matter. In Dr.
Wallach’s ‘Notes on the Presence of
Animal life in the vast depths of the
Sea,” reference is made to the experiments
of Capt. Sir Leopold McClintock during
his survey in H.M. steamer the Buil-
dog, of the telegraphic route vid Green-
land. It is said this navigator brought up
from the bottom of the ocean living star
fish adhering to the deep sea line. Is this,
it is asked, conclusive proof of the existence

E
50 On the Sanatory and

 

of animal life in the depths of the ocean? It
is supposed that these living star fish took
hold of the line near the surface of the
water, and were not actually brought up
from the bottom of the sea.

The preceding facts conclusively establish
the intimate relation existing between each
solar beam, life and organization as far as
the sea is concerned. Speaking in general
“terms, it may be affirmed that animal and
vegetable vitality is incompatible with an
altitude of a few thousand feet above the sea
level on land, and a few thousand feet be-
neath it in the waters. Such is the line of
demarcation ‘between organic and inorganic
matter, life and sterility !

In connexion with this subject it is essen-
tial to consider the amount of pressure

which exists at great oceanic depths, for
Physiological Influence of Light. 51

 

upon this often depends the existence of

marine life. In the Arctic Sea the specific

gravity of the water is lessened on account

of the greater proportion of fresh fluid pro-
duced by the melting of the ice, the pres-

sure at the depth of a mile and a quarter

being 2809 pounds on a square inch of sur-

face. Capt. Scoresby confirms this fact.

He says in his “‘ Arctic Voyages” that the.,
wood of a boat suddenly dragged to a great |
depth by a whale, was found, when drawn
up, so saturated with water forced into its
pores, that it sank in water like a stone for’
a year afterwards. Even sea water is fe
duced in bulk from 20 to 19 solid inches at
the depth of 20 miles. The compression
that a whale can endure is wonderful.
Many species of fish are capable of sustain-
ing great pressure, as well as sudden

E2
52 On the Sanatory and

 

changes of pressure. Divers in the pearl-
fisheries exert great muscular strength, but
man cannot bear the increased pressure at
great depths, because his lungs are full of
air, nor can he endure the diminution of it
at great altitudes above the earth.*

“* According to experiments, water at the

depth of 1000 feet is compressed ;4,th of its

 

bulk ; and at this ratio the pressure at the
depth of one mile would be equivalent to
160 atmospheres, cr 2320lb. on the square
inch ; while at the depth of 4000 fathoms,
or about 44 miles, it would amount to 750
atmospheres! It is owing to this enormous
pressure that closed bottles sunk to great
depths have their corks always forced in;

and that pieces of oakwood carried down to

 

* Physical Geography, by Mary Somerville,
Physiological Influence of Light. 53

 

similar depths, have their fibres and pores so
compressed as to be afterwards incapable of
floating on the surface.”*

I proceed in the next place to notice the
direct as well as indirect influence of light |
on the vegetable kingdom, particularly in.
reference to the modifications effected in the,
colouring principle of plants, as a conse-_
quence of their exclusion from its opera- ,
tion ; but before doing so, I would briefly
refer to some interesting facts illustra-
tive of the tendency exhibited by certain
plants to follow light, from an apparently
instinctive consciousness of its being neces-
sary, if not to their existence, at least for
their well-being. This phenomenon is

beautifully shown by the following facts :—

 

* Physical Geography, by David Page, F.G.S., p. 121:
London, 1864.
54 On the Sanatory and

 

In the spring a potato was left behind in a
cellar where some tools had been kept during
the winter, and which had only a small
aperture at the upper part of one of its
| sides. The potato, which lay in the oppo-
| site corner, shot out a runner which first
| ran twenty feet along the ground, then
crept up along the wall, and so through the
opening by which light was admitted.*
The Chrysanthemum Peruvianum turns
continually towards the sun, and is said to
cover itself with dewy clouds which cool
and refresh the flower during the most

violent heat of the day.

 

* “ Natural History,” by Jesse.

As a general rule all plants bend towards the sun. Mr.
Hunt, however, found that light transmitted through
red fluid media had the effect of repelling plants from the
solar beam. This fact, he says, is not susceptible of expla-
nation.
Physiological Influence of Light. 55

 

Professor Henslow states that some com-
posite as. ‘* Hypocheris radicata” and
“ Apirgia autumnalis” are seen in meadows
where they abound, inclining their flowers
towards the quarter of the heavens in which
the sun is shining. Vaucher says the same phe-
nomena are observed in the Narcissusses and
in certain species of Melampyrum. Similar
phenomena have been observed in other
plants by Priestley, Sennebier, Theodore de
Saussure, Dumas, and Boussingault.

If a leafy shoot of any plant is bent down |
without injury so as to reverse the usual posi-
tion of the faces of the leaves, the latter will
twist upon their petioles and turn their upper |
surfaces to the light. Shoots of slender-
stemmed, quick-growing plants, such as jas-
mine, ampelopsis, &cc., when trained into a

dark recess, turn their growing point back-
56 On the Sanatory and

 

wards on the older part of the stem, also
twisting round to face the light. The in-
fluence of lateral light is distinctly seen in
the plants grown in rooms in front of the
windows, while the drawn-up condition of
closely packed trees is an equally evident
result of preponderating top light.*

The curious phenomena previously re-
ferred to regarding the alteration in the
colour of plants caused by the absence of
the solar beam are well known to all intel-
ligent gardeners and scientific horticulturists.
Plants, as well as animals, nurtured and
grown in perfect darkness, never acquire
their natural colour. The former become

white instead of green.t+

 

* “ Botany, Structural and Physiological.”—By Arthur
Henfrey, F.R.S., 1857.

“ Audi alteram partem.’ ‘The following facts appear in
Physiological Influence of Light. 57

 

This fact is observed in the efiolation or
blanching, as it is termed, of certain kinds

of vegetables, such as celery, seakale, endive,

&c. Their leaves deprived of the sun’s |

 

a slight degree to contradict the general law just enuncia-
ted. “The absence of light exercises a very great influ-
ence over the power possessed by food in increasing the
size of animals. Whatever arouses and excites the atten-

tion of the animal, and makes it restless, increases the |

natural waste of the different parts of the system, and

diminishes the tendency of food to enlarge the body. ,
To the rearers of poultry the rapidity with which

fowls fatten when kept in the dark is well known; and
direct experiment on other animals, whether by keeping.

them in the dark or by the cruel practice of sowing up —

their eyelids, as is adopted in India, have led to similar’
results. Absence of light, from whatever cause produced,)
seems to exercise a soothing and quieting influence on all
animals, increasing their disposition to take rest, making
less food necessary, and causing them to store up a greater
portion of what they eat, in the form of fat and muscle.”
—From a Paper on the “Scientific Principles involved in
the Feeding and Fattening of Stock,’ read by Ed. W.
Davey, M.B.M.R.I., at the Roy. Dub. Soc., April 14,

1859.
58 On the Sanatory and

 

rays do not attain their normal growth or
form, neither is the natural odour of such
‘plants fully developed. Professor Robinson,
descending into acoal mine, accidentally met
with a plant growing luxuriantly. Its form
and qualities were new to him. The sod on
which it grew was removed, potted and care-
fully attended to in his garden.* The etio-
lated plant languished and died ; but the roots
speedily threw out vigorous shoots which,
from the form of the leaves and their peculiar
odour, he readily recognised as tansey. He
repeated similar experiments upon other
plants, viz., lovage, carvi, and mint, with
analogous results.
| The data obtained from the study of
‘physical geography conclusively establish

ithat animal and vegetable substances near

 

* “ Encyclopedia Britannica,”
Physiological Influence of Light. 59

 

the surface of the sea are, in consequence of
their free exposure to light, brilliantly
coloured, and that they gradually lose the
brightness of their hues as they descend
into deep sea water, until the animals of the
lowest zone are found nearly colourless.
‘¢ Here,” says Mr. Hunt, “an everlasting
darkness prevails in the region of silence
and eternal death.”

The rich colour of seaweed found near
and on the surface of the water is owing to
its free exposure to light. The same may be
said of the lovely tints of some of the zoo-
phytes (acting) living in shallow waters,
particularly the sea anemone, which, under
the influence of the bright sun, is seen,
whilst adhering to the rocks, to expand
itself like the blossoms of a flower.

On the surface of the globe the influence’
60 On the Sanatory and

 

_of solar rays is shown in a marked manner.
‘The animals and plants of tropical climates
grow with a richness of colour, far exceed-
ing in beauty and brilliancy those of tem-
perate zones. The latter are less exuberant
in their growth, and are of a darker hue.
In the Arctic regions they are found nearly
colourless. The changes in vital develop-
ment which are observed as we approximate
towards the pole are believed to be governed
more by the isothermes than by the parallels
of latitude; in other words by the mean

amount of heat diffused.* ‘ Though vege-

 

* “ The strength of evidence appears to be in favour of
considering Light, Heat, and Actinism as three distinct
principles or powers, active in regulating the great pheno-
mena of Nature, In the sunbeam these powers are
balanced against each other, and thus are determined those
differences of climate which are not influenced by the phy-
sical conformation of the earth’s surface.”— Hunt.
Physiological Influence of Light. 61

 

tation may greatly differ,” says Dr. Draper,
‘Cin its luxuriance in different climates of
the globe, the manner of action of the light

is always the same. Nothing is gained

 

It has been proved by well-conducted observations, that
with variations of latitude there are variations in the rela-
tions of these three principles.

In the temperate regions of the earth the Actinic power
is active; as we advance to the Tropics, where Heat
increases, and,

“The sun shines for ever unchangeably bright ;”

the chemical power is weak. The photographic picture {
which could be taken in London in a second or two, could |
not be obtained within the Tropics in less then a quarter |
of an hour. It often happens, indeed, that prolonged |
exposure under a blazing sun is insufficient to produce |
any chemical change. Everything appears to favour the
view that the distribution of plants and animals on the
surface of the earth is regulated by the balance of physical
forces in the sunbeam.

In the Seasons we detect the same influences at work,
Actinism or chemical power is greatest in the Spring ; as
the bright Light of Summer advances, the power of the
Solar rays to produce any chemical change is diminished ;
62 On the Sanatory and

 

under the brilliancy of the tropical skies
beyond a shortening of the time required
for the accomplishment of a given amount
of work. No substances are there decom-
posed, even in the organism of plants,
which could not equally well be decomposed
by the feebler light of more temperate
climates, only in these it would demand
more time. The oils and other substances,
almost or quite free from oxygen, which
abound in the plants of the torrid zone, are
not exceptions to, but illustrations of, the
doctrine here set forth.”*

What is the modus operandi of solar light

 

and as we advance to Autumn, the peculiar Heat-rays
come more evidently into action."—Mr. Hunt, in the
« Popular Science Review,” July, 1862.

* “Human Physiology, Statical and Dynamical.”—
J. W. Draper, M.D., 1858, p. 462.
Physiological Influence of Light. 63

 

in altering if not altogether destroying the
chlorophyll, or, to use Dr. Hope’s term, the
chromogen or colouring principle of plants?
Do these changes depend, as Sir John Her-
schel suggests, on a “ chromatic analysis by
which the two distinct elements of colour
are separated by destroying the one and
leaving the other outstanding” ?
Chlorophyll is a substance similar to
wax in its nature, and is contained in the
deep cells or mesophyllum of leaves. It
depends upon the action of light for its
elaboration, and is intimately associated with
the phenomena of active vegetable life, has
a granular form, and is soluble in alcohol.*

As light decreases in the autumn the chloro-

* “ Chromogen ” is said to consist of two separate prin-
ciples, one of which forms a red compound with acids,
and the other yellow with alkalies. Dr. Hope attributes
64 On the Sanatory and

 

phyll in many cases diminishes. The
alteration is caused by the plant losing a
portion of its carbon. ‘Thus may be ex-
plained the changes that take place in the
evergreen and deciduous leaves, producing
what is commonly known by the autumnal
tints.*

The late Professor Lindley made many
interesting experiments with a view of
illustrating the physiological influence of

‘light on the colour of plants.f He esta-

 

the green colour produced by the latter to the mixture of
the yellow matter with the blue infusion.

* Balfour.

+ Every plant, from the time of its germination till the
close of its organic activity, requires for its full develop-
ment a definite quantity of heat. On this subject Schleiden
has made some inquiries, and has taken as his subject the
case of barley. He says “in Egypt, on the banks of the
Nile, barley is sown at the end of November, and harvested
at the end of February; the period of vegetation, there-
Physiological Influence of Light. 65

 

blished that the flowers of the hydrangea
become blue in a soil impregnated with
carbonate of iron, and that all the brilliant
spectacle of vegetable colours disappear
either in consequence of accidents or on the
approach of death. In connexion with this
subject it is curious to notice, he remarks,

that the discoloration of plants is often

 

fore, amounts to about go days, and the mean temperature
of this season is 69° 48! - In:Tuqueres, near to Cumbal,
under the equator, the time of ‘harvest the middle of No-
vember, the mean temperature of this vegetating season of
168 days is so° 12’. At Santa Fé de Bogota they num-
ber 122 days between seed time and harvest, with a mean
temperature of 57° 24’. If, now, the number of days is
multiplied by the figures of the mean temperature, we
obtain 6282 for Egypt, 843338 for Tuqueres, for Santa
Fé, 648948; therefore, as nearly the same number as the
uncertainty in the estimate of the days, the accurate mean
temperature, and the want of knowledge whether or
not the same kind of barley is cultivated in all the places,
will allow us to expect.

The general result as above detailed is thus generalized

F
66 On the Sanatory and

 

determined by the same agents, as in other
cases produce colour, and that certain
organs which have no colour whilst alive
when dead have a decided tint! If the
light be too powerful, a discoloration
takes place in the plant. Cultivators of
tulips with a knowledge of this fact place
their flowers under a tent in order to pre-
serve them from the effect of the direct

action of the sun, which is known to alter

 

by Dr. Draper: “ Every cultivated plant requires a cer-

tain quantity of heat for its development, but it is the same
thing whether this heat is distributed over a shorter or
longer space of time, so that certain limits are not ex-
ceeded ; for where the mean temperature sinks below

. 36° 24', or where it rises above 71° 36’, barley will no
longer ripen. Consequently, to define accurately the con-

ditions of temperature which a plant requires to maintain
it in a flourishing condition, we must state within what
limits its period of vegetation may vary, and what quan-
tity of heat it requires. This was first observed by Bous-
singault.”—“ Human Physiology.”
Physiological Influence of Light. 67

 

their colours. The organic series of plants
exhibit the same phenomenon.

Most aquatic plants, like human beings, |
are said to acquire in death a whitish hue. |
Seaweeds of a most brilliant hue or green
colour become white when they die. The |
same change is observed in the freshwater
confervez.

Although the parts of plants which
originally are white or black become more
or less coloured when exposed to the action
of light, yet organs, once coloured, do not
in reality lose their hues when kept in
darkness ; if they sometimes appear to do
so it is owing to this,—that if half developed
Ieaves are placed in the dark, they grow
larger, and the green matter which coloured
them, being diluted by water and spread

F 2
68 On the Sanatory and

 

over a greater space, appears to be paler
without being itself less coloured.*

When speaking of the influence of the
sun’s light on plants, Dr. Draper says:
‘Through this agent the decomposition of
carbonic acid is effected, and the plant
obtains from the air the carbon it requires,
out of which-its solid structures are for the
most part built. The rapidity with which
the reduction of the carbonic acid takes place
depends upon the brilliancy of the light,
and the amount of carbon thus obtained
upon that condition and the time of ex-
posure conjointly. The amount of light
received from the sun in any locality depends

in a general way, as does the heat, upon the

 

* On Botany, by Dr. Lindley.
Physiological Influence of Light. 69

 

latitudes, but in both cases a multitude of
disturbing agencies intervene. Variations
of moisture control the supply of light by
permitting a translucency, or establishing
its opposite, a cloudiness or murkiness of
the air. Other meteorological causes, as,
for example,. winds, by condensing or re-
moving moisture, act in like manner; so
also do astronomical conditions, especially
by influencing the relative length of the day
and night; for, as we advance towards the
pole, the summer sun is above the horizon
longer and longer. In Northern Europe, |
during the month of June, the sun never
sets, but remains all night, if night it can be -
called, above the horizon ; and, as Berzelius
well remarks, “ Under the influence of this
midnight sun of the North, the life of plants

runs through the same cycle of change in
40 On the Sanatory and

 

six weeks which it takes four or five months
to accomplish in beautiful Italy.”

In connexion with this subject it is of
great interest to consider not only the effect
of the sun on the colour of man, animals,
and plants, but its influence on the varied
phases of insect life. Their maximum
degree of vital manifestation as well as their

variety, richness of hue, &c., are found in

‘countries where the solar beam attains its

highest point of development.

The rate of increase of insect life, in pro-
ceeding from either pole to the equator, is
said to be very various in different longi-
tudes. Their numbers are small in both
the polar regions—more abundant in Tas-
mania and New South Wales—more so in
Southern and Western Africa, Columbia,

and a maximum in Brazil; but North
Physiological Influence of Light. 71

 

America has fewer species than Europe in
the same latitude; and Asia is compara-
tively poor in species, in proportion to its
great extent. The horrors of insect annoy-
ance in the swamps of the great rivers of
tropical America are vividly described by
Humboldt.

The air is one dense cloud of poisonous
insects to the height of twenty feet. In
Brazilthevivid colours and metallic brilliancy
of many of the beetles are extraordinary.

Among the more remarkable varieties of
insect life deserve special mention, ist, the
bees and ants. Of the former each country
has peculiar species; but it is singular that
the honey-bee of North America has been
introduced from Europe.

The ants, of which the species are almost

innumerable, are found chiefly in hot and
72 On the Sanatory and

 

dry climates, and are, perhaps, of all in-
sects, the most remarkable in their habits.
The termite of tropical Africa builds pyra-
midal nests ten or twelve feet in height,
hollowed into chambers of elaborate struc-
ture. The white ant of India devours
everything of animal and vegetable origin,
ascending by covered galleries (for they can-
not bear the light) to the sap of furniture,
beams, &c. But perhaps the most singular

species of all is that of the parasol ants

_of Trinidad in the West Indies, which walk

in long procession each carrying a cut leaf

over its head, as a parasol in the sun, and

these they deposit in holes ten or twelve

feet deep under ground apparently with no
other object than to form a comfortable nest
for a species of white snake, which is invari-

ably found coiled up among them on digging |
Physiological Influence of Light. 3

 

out the deposit.* The scorpion extends in‘
Europe to the north coasts of the Medi-
terranean, but is more abundant in Africa, '
both North and South, where its bite has :
the singular peculiarity, that, although ex- |
cessively painful on the first occasion of its
infliction, and even dangerous to life, the
constitution becomes hardened to it, the
suffering is less on every subsequent occa-
sion, and at length comes to be little re-
garded. Brazil produces a scorpion six
inches in length. ‘The locust, one of the
most formidable scourges in countries in- _
fested by it, migrates in such masses as to
darken the air for successive days, and when

driven into the sea is sometimes thrown up

 

* Mrs. Carmichael’s “Domestic Manners, &c. &c., in
the West Indies,” ii. 327.—Mary Somerville’s “ Physical
Geography,” from whose works these facts are quoted.
94 On the Sanatory and

 

as banks on the shore, poisoning the air by
their decomposition for many miles in
length. They are frequent in Syria and
Barbary, whence they occasionally migrate
to Italy, and during the summer of 1858
several species were taken in the coun-
try, and one or two in London. They
are even said to cross the Mozambique
Channel from the African Coast to Mada-
gascar.*

This section of my subject would be im-
perfectly elaborated if I were to omit all
reference to the marked effect produced by

_ the chemical influence of light in modi-

fying the active principle of certain medi-

cinal drugs.t| The phenomena referred to

 

* As quoted by Sir John Herschel: “Physical Geo-
graphy.”
{ Dr. Draper performed some interesting experiments
Physiological Influence of Light. 75

 

are of deep practical importance, not only
to the pharmaceutical chemist but to the
physician. If the powdered leaves of hem- |
lock, aconite, foxglove, or henbane, are ex-
posed for any length of time to a strong
light, their colour becomes changed, ‘‘ pass-|
ing,” says Mr. Hunt, “ slowly from a green
into a slaty grey, and ultimately into a dirty
yellow.” A decomposition also takes place,
by which the medicinal activity of the plant is’
seriously altered if not made altogether inert.|

Hence the importance of preserving the

previously mentioned pharmaceutical pre-

 

on the production of hydrochloric acid by the direct
union of chlorine and hydrogen under the influence of
light, both artificial and solar, and also on the decom-
position of peroxalate of iron, from which the carbonic
acid is readily disengaged, by which he established that
the primary condition essential for the chemical action of
light is the absorption of some of its rays.
76 On the Sanatory and

 

parations in well-covered bottles, thus care-
fully excluding them from the influence of
the sun’s rays.

By what chemical or physiological laws
are we to explain the curious facts referred
to by Mr. Hunt, when alluding to the
effect of light in modifying the potency of
some vegetable tinctures, and particular
| medicinal powders? Pulverized rhubarb
and ginger adhere with considerable firmness
to the sides of the bottles exposed to the
light, whereas the sides in shadow are left
clear. If camphor is kept in a bottle, crys-
tals will be formed on the sides of the glass
upon which the light falls. If that side is
turned from the light the crystals will be
gradually removed, and again be deposited
on those parts upon which the rays of light

first impinge.
Physiological Influence of Light. 77

 

Hydrocyanic acid is supposed to undergo |
decomposition if exposed to the action of |
light ; hence it is preserved in blue-coloured .
bottles.

Gum guaiacum is well known toturngreen
under the prolonged influence of the solar |
light. Dr. Wollaston took two specimens -
of paper coloured with a yellow solution of
this gum in alcohol, and exposed one of
them to air and sunshine, the other to air
in the dark. The former was turned per-
ceptibly green in five minutes, and the
change was complete in a few hours, while
the latter was not discoloured after the lapse
of many months.

In connexion with this subject, I have to
consider in detail the exceedingly interesting
experiments which have been made with a

view of ascertaining the modifications that
78 On the Sanatory and

 

take place in the vital and chemical influence
of light when passed through media of
_varied tints. Apart from the coloured rays
observed when the spectrum is subjected to
the effects of some absorbing medium, there
is an agent which is said to permeate the
glass or fluid, which has a decided thermic
influence. These phenomena are recorded
with philosophic exactness by Mr. Hunt.
. The following is a summary of the facts he
has conclusively established in relation to
this subject: the highest degree of tempera-
ture is not obtained behind red media, but a
yellow or orange tint ; in fact, the maximum
degree of temperature is found behind a
colourless fluid. Red glasses and fluids
absorb a larger quantity of the heat rays
\ than any others excepting black ones. The
‘effect of the rays of light passing through
Physiological Influence of Light. 79

 

different coloured media on the germination —
of plants has been beautifully illustrated. |

The following is the order in which the
colours stand, when viewed in relation to
their vital or germinating effects: 1, orange ;
2, red; 3, ruby; 4, yellow; 5, blue; 6,
green: “The roots of tulips,” says Mr. :
Hunt, “under the orange glass, developed
the cotyledons a week earlier than those
under the yellow, blue, or green glasses.
The greatest progress in germination was
made by the tulips under the yellow and
orange glasses ; but the leaves under each of
these were by no means healthy, particularly
under the yellow glass, but which had a
singular delicate appearance, being of a very
light green colour, and covered with a most
delicate white bloom.”

Under the influence of the colour pre-
80 On the Sanatory and
/

 

viously referred to, the leaf stalks of the
tulips shot up remarkably long, and were in
both cases white. Under the orange glass,
a small flower bud appeared in the plant ;
it, however, soon perished with the plant
itself. Under the yellow glass no buds
appeared, and the vitality of the plant soon
failed. ‘Tulips exposed to the influence of
light passing through ruby and red glasses
shot up in a single lobe. The duration of
the life of the plant did not extend over
three or four weeks, and it did not rise over
two or three inches above the soil. Under-
neath the green glass the plants grew slowly
but strongly. The stem was long, having a
small leaf at the end, not more than two-
thirds of an inch in diameter. The flower-
buds generated under these circumstances

never could be made to blossom, notwith-
Physiological Influence of Light. 81

 

standing the greatest care and attention was
bestowed upon them. The attempt to
develop the bud appeared to exhaust the
vitality of the plant, and it soon died.
Under blue glasses the roots germinated
less quickly than in the open ground, but
exhibited a greater degree of vitality. Some-
what similar phenomena were observed with
regard to the germination of seeds when
exposed to the influence of light passing
through various coloured media, solid or
fluid in their nature. Dr. Draper found
that under the influence of the bright sun
of Virginia, plants have grown well in the
light which has been made to permeate
through a considerable thickness of intense
yellow solution.

When vensideting the chemical and phy-!
siological influence of light it is impossible

G
82 On the Sanatory and

 

\ ; :
to overlook the important results obtained by

| Professors Bunsen and Kirchhoff by the aid
of the spectroscope, or analysis of the sun-
light by the prism. When this instrument
is applied to the investigation of a solar beam
it is found to be traversed by a number
of vertical dark lines, (‘* Fraunhofer’s lines,”

as they are designated.)* The sunlight is

 

* “Tn order to explain the occurrence of the dark lines
in the solar spectrum, we must assume that the solar
atmosphere incloses a luminous nucleus, producing a con-
tinuous spectrum, the brightness of which exceeds a
certain limit. The most probable supposition which can
be made respecting the Sun’s constitution is, that it con-
sists of a solid or liquid nucleus, heated to a temperature
of the brightest whiteness, surrounded by an atmosphere
of somewhat lower temperature. This supposition is
in accordance with Laplace’s celebrated nebular theory
respecting the formation of our planetary system. If
the matter, now concentrated in the several heavenly
bodies, existed in former times as an extended and con-
tinuous mass of vapour, by the contraction of which sun,
planets, and moons have been formed all these bodies
Physiological Influence of Light. 83

 

thus proved to contain various metals.
Among these are iron, nickel, sodium,
calcium, magnesium, chromium, and in small
quantities, barium, copper, and zinc. Gold,
silver, mercury, aluminium, cadmium, tin,
lead, antimony, arsenic, strontium, and
lithium are not, according to the experiments

of Professor Kirchhoff, found in the solar

 

must necessarily possess mainly the same constitution.
Geology teaches us that the earth once existed in a state
of fusion; and we are compelled to admit that the same
state of things has occurred in the other members of our
solar system. The amount of cooling which the various
heavenly bodies have undergone, in accordance with the
laws of radiation of heat, differs greatly, owing mainly
to difference in their masses. ‘Thus whilst the moon has
become cooler than the earth, the temperature of the
surface of the sun has not sunk below a white heat.
Our terrestrial atmosphere, in which now so few elements
are found, must have possessed, when the earth was in a
state of fusion, a much more complicated composition, as
it then contained all those substances which are volatile at
a white heat. The solar atmosphere at this present

G2
84 On the Sanatory and

 

atmosphere. It is supposed that the rays
of light which form the solar spectrum and
present the interesting phenomena previously
referred to have passed through the vapour
of iron, and have thus suffered the absorp.
tion which the vapour of iron must exert.

It has been maintained that these iron

 

time possesses a similar constitution. The idea that the
sun is an incandescent body is so old, that we find it
spoken of by the Greek philosophers. When the solar
spots were first discovered, Galileo described them as
being clouds floating in the gaseous atmosphere of the
sun, appearing to us as dark spots on the bright body of
the luminary. He says that if the earth were a self-
luminous body, and viewed from a distance, it would
present the same phenomena as we see in the sun.—
“Researches on the Solar Spectrum and the Spectra of
the Chemical Elements.” By G. Kirchhoff, Professor of
Physics in the University of Heidelberg. Translated by
Henry E. Roscoe, B.A., Professor of Chemistry, Owen’s
College, Manchester. London, 1862.
Physiological Influence of Light. 8&5

 

vapours are contained in the atmosphere of
the sun or in that of the earth. ‘It is
not easy to understand,” says Professor
Kirchhoff, ‘“ how our atmosphere can con-
tain such a quantity of iron vapour as would
produce the very distinct absorption lines
which are seen in the solar spectrum. This
supposition is rendered still less probable
by the fact that these lines do not appreci-
ably alter when the sun approaches the
horizon.

“Tt does not, on the other hand, seem at
all unlikely, owing to the high temperature
which we must suppose the sun’s atmo-
sphere to possess, that such vapours should
be present in it. Hence the observations
of the solar spectrum appear to prove the
presence of iron vapour in the solar atmo-

sphere with as great a degree of certainty as
86 On the Sanatory and

 

can be attained in any question of natural
science. *
_ The important results thus obtained re-
garding the properties of light by means of
the solar spectrum, will in all probability
tend greatly to elucidate the physical consti-
tution of the sun, the nebular theory respect-
ing the formation of the planetary system,
and the geological character of the earth;
but into the consideration of the various
hypotheses suggested to explain the pheno-
mena relating to these interesting philoso-
phical points, it would be foreign to my
purpose to enter.

When addressing myself to the hygienic
influence of light, I purpose again recurring

to Professor Bunsen and Kirchhoff’s dis-

 

* “Researches on the Solar Spectrum, &c.” By Pro-
fessor Kirchhoff.
Physiological Influence of Light. 87

 

covery, for the purpose of ascertaining to)
what extent the development of the red-|
blood cell and the iron found in the general,
circulation depend upon the mechanical or
chemical effect of the solar beam (contain-,
ing in its composition this metal) upon the
portions of the body exposed to its opera-
tion.

It is not my intention to analyse the’
morbid effects of solar light in the gene-
ration of specific diseases. I leave the
consideration of this portion of the sub-
ject in the able hands of Sir James Ranald |
Martin, and other well-known writers on
the Diseases of Tropical Climates.

That a prolonged exposure to the intense
rays of the sun injuriously affects the
health is generally admitted. Inflammation

and congestion of the brain; engorgement,
88 On the Sanatory and

 

inflammation, enlargement, and torpidity
of the liver; intermittent, remittent, gas-
tric, yellow, and congestive fevers ; dysen-
tery, and cholera, are among the principal
maladies incidental to a protracted residence
in the tropical zone.

Fatal attacks of what in India is termed

>

“heat apoplexy,” or ‘coup-de-soleil,” are
common in various parts of that country,
as the effect of an indiscreet exposure to

the vertical rays of the sun.
Physiological Influence of Light. 89

 

PART II.

THE LUNAR RAY.
I woutp refer briefly to the ancient opinions
respecting the influence of the moon.
From the earliest periods of antiquity,
the idea generally prevailed, not only that
the moon exercised a specific effect in
the production and modification of dis-
ease, mental and bodily, but played a pro-
minent and important part in the develop-
ment of the character of nations, and in
determining the destinies of the human
race. Amongst the ancients the moon
was viewed as an object of superstitious

regard. They held her in great religious
go On the Sanatory and

 

veneration, considering her influence supe-
rior even to that of the sun; in fact, they
worshipped her as a Deity. The new
moons, or the first days of the month, were
kept with great pomp and ceremony as
national festivals. ‘The people were obliged
to rest on those days. The feast of new
moons was a miniature of the feasts of the
prophets. Eclipses, whether of the sun or
moon, were looked upon as evidences of
Divine displeasure. The Greeks consulted
the different phases of the moon before con-
tracting marriage, and the full moon, or
the times of conjunction of sun and moon,
were considered the most favourable periods
for celebrating the ceremony, in conse-
quence of the impression that the reproduc-
tive functions were under lunar influence.

“‘ This connexion of the moon,” says Dr.

Laycock, ‘‘ with the measure of time seems
Physiological Influence of Light. 91

 

to have brought that planet into relation
with the religious rites of ancient nations,
as the Egyptians and Jews; and, also, to
have given origin (in part) to the mytho-
logical idea so extensively prevalent of a
lunar influence on marriage and child-bear-
ing. Even the barbarous Greenlanders, as
Egede informs us, believe in this super-
stitious notion. They absurdly imagine that

the moon visits their wives now and then; and

that staring long at it when at its full will

make.a maid pregnant! Amongst the ancient
nations the general idea was, that the lunar
influence varied according to the age of the
moon. Bubastis, the Egyptian Diana, was
not equally favourable to parturient females
and their offspring in her different phases.
Amongst the Jews the full moon was
believed to be lucky, and the other phases

disastrous.”
92 On the Sanatory and

 

“The full moon,” says the Rabbi Abra-
vanel, “is propitious to new-born children :
but if the child be born in the increase or
wane, the horns of that planet cause death ;
or, if it survive, it is generally guilty of
some enormous crime.” The Greeks and
Romans entertained a similar idea respect-
ing the lunar phases. The general opinion
seems to have been, that the moon was
propitious in proportion as its luminous
face was on the increase. The ancient
Greeks considered the day of the full
moon to be the best day for marriage.
Euripides makes Agamemnon answer,
when asked on what day he intends to

be married,
“ Orav Sednuns edtux}s EXOn KvKdos.” *

Hesiod asserted that the fourth day of

 

* “Iphigenia,” act v. 717.
Physiological Influence of Light. 93

 

the moon was propitious, but the eighteenth
was bad, especially to females. Aristotle
maintained that the bodies of animals were
cold in the decrease of the moon, and that
the blood and humours are then put in
motion, and to those revolutions he ascribes
the various derangements peculiar to women.

Lucilius, the Roman satirist, says that
oysters and echini fatten during lunar aug-
mentation, which also, according to Gellius,
enlarges the eyes of cats; and that onions
throw out their buds in the decrease of the
moon, and wither in her increase, which
induced the people of Pelusium to avoid
their use. Horace also notices the supe-
riority of shell-fish during the moon's in-
crease.

Pliny takes notice of the same fact. He
also adds that the streaks on the livers of
94 On the Sanatory and

 

rats answer to the days of the moon’s age;
- and that ants never work at the time of the
lunar changes. He also informs us that
the fourth day of the moon determines the
prevalent wind of the month, and con-
firms the opinion of Aristotle that earth-
quakes generally occur about the new moon.
Pliny asserts that the moon corrupts all
dead carcases exposed to its rays, and pro-
duces drowsiness and stupor in those who
sleep under her beams. He further con-
tends that the moon is nourished by rivers,
as the sun is fed by the sea. Galen asserted
that all animals who are born when the
moon is falciform, or at the half quarter,
are weak, feeble, and short-lived; whereas
those who come into the world during the

full moon are healthy, vigorous, and long-

lived,
Physiological Influence of Light. 95

 

Lord Bacon adopted the notion of the
ancients. He maintained that the moon de-
veloped heat, induced putrefaction, increased |
moisture, and excited the motion of the
spirits.* Van Helmont affirmed that a
wound inflicted during the period of moon- |
light is most difficult to heal, and boldly
asserted, that if a frog be washed clean and
tied to a stake under the rays of the moon
in a cold winter’s night, on the following
morning the body will be found dissolved’
into a gelatinous substance bearing the
shape of the reptile, and that coldness
alone, without the lunar action, will never
produce the same effect !

The Spartans considered the moon to

have great influence, and no motive could

 

* It is recorded that this great philosopher always had
a severe attack of syncope at the time of a lunar eclipse.
96 On the Sanatory and

 

induce them to enter upon an expedition,
or march against the enemy, until the full
of the moon. The Greeks and Romans
believed that the moon presided over child-
birth. The patricians of Rome wore the
ifigure of a crescent upon their shoes, to
| distinguish them from the inferior order of
‘men. The crescent was called /u/ula. Hero-
‘dotus records that when the Lacedemonians
visited Athens, after the battle of Marathon,
they waited until the moon had passed its
full before they continued their march.*
The ancient alchymists attempted to localize
planetary influences, maintaining that the
heart, which represented, according to their
physiological notions, the vital principle, was

under the special protection of the sux ; that

 

* Erato. xx.
Physiological Influence of Light. 97

 

the drain was regulated and controlled by the
moon ; that Fupiter presided over the Jungs,
Mars the liver, Saturn the spleen; that
Venus took the kidneys under her kind con-
trol, and Mercury sat in judgment upon the
reproductive functions. They were also of
opinion that the morning regulated the
blood, noon the bile, evening the atra-bile,
and night the cold phlegmatic constitution.
It will appear by the previously recorded
data that from the earliest periods in the
history of the world the idea of the phe-
nomena of organic life being subject to
planetary control, was popular amongst

enlightened and philosophic men.* The

 

* ¢ A knowledge of the ancient and popular belief in
Sidereal influence will enable us to explain many super- |
stitions in physic; the custom, for instance, of adminis. |

f

tering cathartic medicines at stated periods and seasons,
originated in an impression of their being more active at /

i

H
98 On the Sanatory and

 

following passage proves that the great

 

particular stages of the moon, or at certain conjunctions
of the planets; a remnant of this superstition still exists
to a considerable extent in Germany; and the practice of
bleeding at ‘spring and fall, so long observed in this
country, owed its existence to a similar belief. It was in
consequence of the same superstition that the metals were
first distinguished by the names and signs of the planets ;
and as the latter were supposed to hold dominion over
time, so were astrologers led to believe that some, more
than others, had an influence on certain days of the week;
and, moreover, that they could impart to the correspond-
ing metals considerable efficacy upon the particular days
which were devoted to them; from the same belief, some
bodies were only prepared on certain days in the year;
the celebrated earth of Lemnos was, as Galen describes,
periodically dug with great ceremony, and it continued
for many ages to be highly esteemed for its virtues; even
at this day, the pit in which the clay is found is annually
opened with solemn rites by the priests, on the 6th day
of August, six hours after sunrising, when a quantity is
taken out, washed, dried, and then sealed with the Grand
Signior’s seal, and sent to Constantinople. Formerly it
was death to open the pit or to seal the earth on any
other day in the year. In the botanical history of the
Middle Ages, as more especially developed in Macer’s
Physiobogical Influence of Light. 99

 

Roman satirist believed in lunar influ-

ences :-—

“Ut mala quem scabies aut morbus regius urguet,
Aut fanaticus error, et iracunda Diana,
Vesanum tetigisse timent fugiuntque poétam,
Qui sapiunt.”*

These notions have not been confined
to classical regions, ancient authorities,
or to the fanciful creations of the poet.
They have existed amongst barbarous, un-
civilized, and unlearned nations, who were
profoundly ignorant of the views pro-
pounded by the astrologers of old, or by

the medical writers, who had somewhat en-

 

Herbal, there was not a plant of medicinal use that was
not placed under the dominion of some planet, and must
neither be gathered nor applied but with observances that
savoured of the most absurd superstition, and which we
find were preserved as late as the seventeenth century by
the astrological herbarists, Turner, Culpepper, and Lovel.”
—Dr. Paris’s “‘ Pharmacologia.”

* Hor. “ Ars Poetica,”

H 2
100 On the Sanatory and

 

grafted the study of medicine upon that of
astrology and astronomy. In referring to
_the alliance which formerly obtained between
the two sciences, it has been well observed
| by an able writer and close observer of
: nature, “ that no judicious person can doubt
that the application of astrology to medi-
cine, though it was soon perverted and
debased till it became a mere craft, originated
in actual observations of the connexion be-
tween certain bodily affections and certain
times and seasons. Many, if not most, of
the mischievous systems in physics and
divinity have arisen from dim perception or
erroneous apprehensions of some important
truth, and not a few have originated in the
common error of drawing bold and hasty

inferences from weak premises.”*

 

* Southey.
Physiological Influence of Light. 10%

 

That the theory of planetary influence
should have been advocated in early times,
and have found zealous supporters, not only
amongst the illiterate, but amongst learned
and scholastic men, need not excite surprise
when we consider how easily susceptible of
demonstration is the fact of the moon’s
powerful effect in producing that regular
flux and reflux of the sea which we call
tides. Astronomers having admitted that
the moon was capable of producing this
physical effect upon the waters of the ocean,
it was not altogether unnatural that the
notion should become not only a generally
received, but a popular one, that the ebb
and flow of the tides had a material influence
over the bodily functions.. The Spaniards
imagine that all who die of chronic diseases

breathe their last during the ebb. Southey
102 On the Sanatory and

 

says, that amongst the wonders of the isles
and city of Cadiz, which the historian of
that city Suares de Salazar enumerates, one
is according to P. Labat, that the sick
never die there while the tide is rising or at
‘its height, but always during the ebb. He
restricts the notion to the isle of Leon, but
implies that the effect was there believed to
take place in diseases of all kinds acute as
well as chronic. ‘Him fever,” says the
Negro in the West Indies, “shall go when
the water come low; him always come not
when the tide high.” The popular notion
amongst the Negroes appears to be that
the ebb and flow of the tides are caused
by a “fever of the sea,” which rages for six
hours, and then intermits for as many more.

There exists in the writings of many

able, truthful, and conscientious men a
Physiological Influence of Light. 103

 

vast body of valuable and indisputable
evidence in support of the theory of plane-
tary influence. I subjoin the names of
the principal authorities on the subject :—
Ballonius, Ramazzini,* Joubertus,+ Joannes
Morellus,t Mead,§ Gemma,]|| Parzeus,q Dr.
Nicolas Fontana,** Dr. Cullen,++ Dr.
Balfour,tt Dr. James Lind,$§ Dr. Jack-

 

* De Constitutionibus trium sequentium annorum, 1692,
1693, 1694, in mutinense civitate et illius Ditione, Dis-
sertatio; which essay will be found in the first volume of
his Opera Omnia Medica et Physiologica.

+ On Epidemics. t{ On Putrid Fever.

§ De Imperio Solis et Lune in corpora humana et
Morbis inde oriundis,

|| On the Plague of 1575- { On the Plague.

** Osservazioni sopra le Malattie che attacano li Europei
nei Climi caldi, &c. Livorno, 1781.

tT First Lines.

tt Effects of Sol-Lunar Influence in Fevers. London,
1815: §§ On Putrid Fevers.
104 On the Sanatory and

 

son,* Dr, James M‘Grigor,t Dr. James Gil-
christ,t Dr. James Johnson,§ Dr. Liddell, ||
Dr. Diemerbroeck ;§ and ‘in our own imme-
diate epoch, Drs. Orton,** Radcliffe, and
Laycock on the periodicity connected with dis-
easeand associated with thevital phenomenatt
—Sir James Ranald Martin, C.B., F.R.S.,tt
Dr. Milligan,§§ William Ramsay,|||| Dr.

 

* Treatise on the Connexion of the New and Full
Moon with the Invasion and Relapse of Fevers.—London
Medical ournal for 1787. Also, his Treatise on the
Fever of Jamaica.

+ Medical Sketches of an Expedition to Egypt.

+ On the Diseases of India.

§ On the Diseases of Tropical Climates.

|| On the Diseases of Tropical Climates,

| On the Plague.

** On Cholera.

“ Vols. ii. and iti., Lancet, 1842-3.

~ On the Diseases of Tropical Climates, Second
Edition. .
§§ Curiosities of Medical Experience.
|||| Astrologia Restaurata. oe
. Physiological Influence of Light. 105

 

Prichard,* Arago,t and Dr. Lardner.{
Many of the great medical authorities of
antiquity were clearly of opinion that the
celestial bodies exercised a marked influence
upon the bodily and mental functions.
Dr. Haslam asserts that Hippocrates, whom |
he designates as a “ philosopher and correct
observer of natural phenomena,” did not
place any faith in the generally received
notion respecting the influence of the moon.
This is clearly an error. Hippocrates im-
bibed so strong a belief regarding the effects
of the celestial bodies upon the vital mani-
festations that he expressly recommends no
physician to be entrusted with the treatment
of disease who was ignorant of astronomical

science; and he expressly advises his son

 

* Analysis of.the Egyptian Mythology.
+ Meteorological Essays. . + On Lunar Influence.
106 On the Sanatory and

 

Thessalus, to study the science of numbers
and geometry, affirming that the “rising
and setting of the stars have great effect
upon the distempers.”*

The critical days, or crises as they were
termed, were said to correspond with the in-
terval between the moon’s principal phases.+
Galen adopted the Hippocratic notion,
Hence the lunar periods were said by him
to be connected with the exacerbation of
particular diseases.

The doctrine of lunar influence has de-
scended to modern times, and notwithstand-

ing a section of the scientific world has

 

* Epist. ad Thessalum de aére, aquis, et locis.

+ The crises which Hippocrates describes by the words
imperfecte judicabantur, were, according to Dr. Balfour,
nothing more than intermediate inter-lunar crises; and
those to which he applies the terms perfecte judicabantur,
were final inter-lunar crises.
Physiological Influence of Light. 104

 

altogether repudiated the idea, it has never-
theless found zealous advocates among
learned men. Writers of admitted judg-
ment and sagacity have been recognised in
the ranks of those who support this theory.
At the threshold of this important and
interesting inquiry it will be well to pause
and consider, why any number of men of
science should exhibit a disposition to dis-
countenance this notion of planetary in-
fluence? Dr. Orton endeavours to answer
the question.

“The difficulty of explaining lunar in-
fluence appears to be the great obstacle
which in modern times has stood in the way
of the belief of its existence and general
prevalence. The ancients, who less minutely
scrutinized the chain which connects effects

with remote causes, implicitly believed in
108 °° On the Sanatory and

 

the existence of this power, simply. be-
cause they saw the coincidence of its
effects and certain states of the heavenly
bodies, although they knew not that these
bodies in other respects exert a physical
influence on the earth. But since the’ pro-
gress of science has enabled men to trace
more distinctly the manner in which changes
arise from and produce other changes, this
empirical mode of reasoning has ceased to
be satisfactory ; and the improvement of
philosophy seems, in some instances, to have
actually operated as a barrier to its further
progress, by furnishing negative arguments
against the existence of causes which we are
unable to connect by any satisfactory theory
with their effects. Every occurrence in
Nature has been attempted to be accounted

for on rational and general principles,’ and
Physiological Influence of Light. 109

 

it has been found much easier to deny than
to explain the operation of the sol-lunar
power. If, however, these principles were
to be applied in all their extent to the other
branches of medicine, they would strike at
the very root of that imperfect science ; for
we know little more of the modus operandi
by which ipecacuanha produces vomiting,
or jalap produces purging, than we do of
that by which the new or full moon pro-
duces attacks of intermittent fever, of
mania, or epilepsy. We have the same
kind of evidence of the agency of both these
classes of causes; and after the proofs which.
have been adduced of sol-lunar influence, it
would be nearly as preposterous to deny its
existence—because we cannot account for it,
because it does not produce its effects on all

persons, or because the same occurrences
110 On the Sanatory and

 

- frequently arise without its agency, as it
would be to assert that a common dose of
ipecacuanha or jalap will not produce vomit-
ing or purging for precisely the same
reasons. It does not, nevertheless, appear
“to be impossible to make some approach to
the explanation of the nature of sol-lunar
influence on known principles. It is proved,
on the known laws of gravitation, that the
various situations of the moon necessarily
must have determinate effects on the
atmosphere. Observations have shown
that such is the case, and on these
data considerable progress has already been
made in the elucidation of this interesting
subject.

“It appears to be very evident that
sol-lunar influence is much more powerful

within the tropics than in other parts of the
Physiological Influence of Light. 111

 

world ; and this may in some degree account
for the little credit which it has met with;
for little information, in comparison to the
opportunities which are presented, has been
conveyed from these countries to the native
regions of philosophy. Dr. Balfour has
indeed been impressed with all the impor-
tance of his subject, and even more than all ;
his situation and experience were such as to
entitle his opinions to the highest attention,
and he has given them to the world in the
fullest manner; but he has failed in gaining
a complete credit, probably from the dog-
matical style which he has adopted, and
from his having fallen into the error which
is usually fatal to theorists—that of aiming

at too much.’”*

 

* Dr. Reginald Orton’s “Essay on the Epidemic
Cholera of India,” p. 202. 1831.
112 On the Sanatory and

 

Dr. Balfour’s treatise will form the basis
of some remarks when I come particularly
to analyse the facts recorded by the different
authorities relative to lunar influence in the
production of disease. There has, I think,
been a disposition to discourage of late years
any minute, special, and scientific investiga-
tion of the facts recorded by men of veracity,
on the presumption that the subject is alto-
gether fanciful, visionary, and utopian. If
the question has been seriously considered
with a view to elicit truth, has the inquiry
been calmly and dispassionately pursued,
and that, too, by competent observers,
possessed “of the preliminary amount. of
mathematical, astronomical, and meteoro-
logical science indispensably necessary. in
order to arrive at anything like a satisfactory

result or scientific conclusion? I much
Physiological Influence of Light. 113

 

doubt the fact. In general conversation on
the subject, the observation is often made,
“Oh, I have not overlooked the study of
the subject ; I have been careful to observe
whether the moon does really exercise any ;
influence in modifying the type of disease,
and have arrived at the conclusion that the :
notion is a puerile and fallacious one.”
But when the question is asked as to the
mode of investigation which has been adopted,
it will generally be found to have been loose
and unscientific. With undoubtedly a
sincere disposition to arrive at the truth, the
method adopted by the inquirer has not been
so sufficiently philosophic, logical, and exact
as to entitle it to the respect of learned men.
To establish the inconsistency displayed by
writers on the subject, Dr. Orton cites
passages from two standard works of

I
114 On the Sanatory and

 

scientific reference, relating to the subject
of lunar light, in which the authors deny
in toto its effects on the human organism.
“The hypothesis of planetary influence,”
says one of the authorities, ‘‘ has originated
and passed by with the age of astrology.”*

Another writer remarks that, ‘as the
most accurate and sensible barometer is not
affected by the various positions of the
‘moon, it is not thought likely that the
human body should be affected by them.”
“But in the following page,” says Dr.
Orton, “ the writer furnishes a body of
evidence to establish that the barometer has
been found to be very remarkably affected by
the various positions of the moon.” It is not

easy to reconcile such statements.

 

* Rees’ “ Encyclopedia.” “Encyclopedia Britannica.”
Physiological Influence of Light. 115

 

Before proceeding to analyse the facts
cited by the authorities previously referred
to, as illustrative of the influence of lunar
light in the production of bodily disease, I
would briefly direct attention to some of
the well-known data regarding periodicity, as
associated with the origin, progress, and type
of disease. The theory of lunar influence.
is in a great measure based upon this well-
established law. The doctrine of periodi-.
city, as exhibited in the phenomena of life,
is not altogether of modern origin.* The
ancients were too close and accurate stu-

dents and observers of nature to have

 

* Certain plants appear, in an inexplicable manner, to
be influenced by the law of periodicity as well as by light. |
Dr. Balfour, when referring to this subject, observes that a :
plant accustomed to flower in daylight at a certain time
will continue to expand its flowers at the wonted time, .

even when kept in a dark room. De Candolle made a,

12
116 On the Sanatory and

 

overlooked the fact. The phenomena of
menstruation were the subject of - particular
observation in all ages, and its singular and
well-marked periodical character was attri-
buted to the operation of causes acting
independently of those organic laws sup-
posed to regulate the special functions of
life. This periodicity is observed in a large
class of febrile affections, particularly in the
intermittent, remittent, and bilious fevers
of tropical climates, in the class of disease
termed zeuroses, in all spasmodic and con-
vulsive disorders, particularly in epilepsy

and its allied affections, in many forms of

 

series of experiments on the flowering of plants kept in
darkness and in a cellar lighted by lamps. He found that
the law of periodicity continued to operate for a consider-
able time, and that in artificial light some flowers opened,
while others, such as species of convolvulus, still followed
the clock hours in their opening and closing.
Physiological Influence of Light. 117

 

insanity, and in the diseases classed under |
the term exanthemata.

There is much in the recorded facts and
observations embodied in the valuable trea-
tises of Drs. Mead and Balfour,to strengthen :
the presumption that the periodicity re- |
ferred to arises directly or indirectly from sol-
lunar influences. Medical meteorology has
not yet assumed the character and position
of an exact and demonstrative science, and
although I would concede much to those
who have patiently considered this interest-
ing branch of philosophic inquiry, I am in
duty bound to pause before attributing too
much power to those external agents (active
I admit them to be) that are considered to
regulate and control the great principle of
life, either in its healthy or morbid mani-

festations. Can it not be demonstrated that
118 On the Sanatory and

 

the vital law regulating the phenomena of
menstruation acts independently of certain
external agencies? I repeat, is this fact not
susceptible of proof? Until we are satisfied
that this important uterine function 1s not
dependent upon a special organic law in-
herent in or acting specifically upon the
uterus itself, shall we not be travelling
beyond the limits of a safe and logical
induction, by assuming as an indisputable
and demonstrable fact, that the phenomena
to which I refer are the effect of lunar
conditions, or dependent upon certain
meteorological states of the atmosphere in-

duced by the physical aspects of the moon ?*

 

* These periodical discharges are said to be more pro-
fuse in countries near the equator than towards the poles.
Hippocrates notices this fact, and uses it to explain the
sterility of the women of Scythia.
 

Physiological Influence of Light. 119

I now proceed with the historical analysis
of the subject.

Dr. Mead’s treatise* appeared soon after
Sir Isaac Newton’s immortal discoveries
burst like a flood of dazzling light upon the
world. Dr. Mead occupied a high position
amongst the /iterati of Europe. His repu-
tation as a scholar, physician, man of
letters, and a lover and cultivator of science,
was universally established. He was the
intimate friend of Pope, Newton, and of
Halley. He stood high in the estimation
of foreign princes and kings, and the learned
and scientific men of all countries eagerly
sought his acquaintance, and felt honoured
by his friendship. It is recorded in his
biography that the King of Naples for-

 

“De Imperio Solis et Lune in corpora humana et
Morbis inde oriundis.”
120 On the Sanatory and

 

warded to Dr. Mead the two first volumes
of Signor Bajardi’s erudite work on the
antiquities of Herculaneum, paying him the
compliment of asking in return a complete
collection of his own works, and at the
same time inviting him to his palace, for
the purpose of showing him his valuable
collection of Herculaneum antiquities. Con-
sidering the position of Dr. Mead, every-
thing that fell from his pen was read with
avidity, and his observations on all subjects
were considered to be based upon a patient
and accurate study of the great book of

nature. His work, previously referred to,

'was read with universal interest; and al-

though it gave rise to much controversy, it
nevertheless commanded the respect of his
learned contemporaries. It was the first

modern treatise on the subject, and proceed-
Physiological Influence of Light. 121

 

ing from a physician of Mead’s reputation,
it at once formed the topic of general con-
versation and criticism. Such being the
character of the work, I proceed briefly to
analyse its contents.

Dr. Mead, in the prefatory part of his

i
i
{

treatise, dwells much upon the importance |

of a previous acquaintance with the mathe-
matical principles of natural philosophy, in
order fully to comprehend the subject of

lunar influences.

He then attempts to demonstrate, in the |

first place, that the sun and moon, in pro-
portion as they approach near the earth,

independently of their influence upon heat

and moisture, must, at certain times, mate-—

rially modify vital phenomena. The author,
in the second place, cites facts illustra-

tive of his theory, and then makes some

Z
1% On the Sanatory and

 

suggestions in reference to the practical
division of the subject.

Dr. Mead enters fully into the considera-
tion of the effect of the moon on the winds,
observing that the most boisterous seasons
of the year occur about the vernal and
autumnal equinox. It is a matter, he re-
marks, of common observation, that in the
calmest weather there is some breeze at
mid-day, at mid-night, and also at full sea
—that is, about the time the sun and moon
arrive at the meridian, either over or under
our hemisphere. Without entering more
minutely into analysis of Dr. Mead’s able
and ingenious essay, his theory of sol-lunar
_ influence may be thus briefly epitomized:
_—dAccording to Dr. Mead, the attraction of
the sun and moon being increased at the

 syzygies (new and full moon), and the
Physiological Influence of Light. 123

 

perigees (those situations in the moon’s
orbit in which she approaches nearest to the
earth), and the passages over the equator,
the weight of the atmosphere is consequently
diminished, and it is rendered mechanically
unfit for respiration, and for supporting the
due degree of pressure on the surface of the
body. Dr. Mead endeavours to establish,
on Newtonian principles that in all the
situations in which the sun and moon have
been found to produce their greatest effects
in raising the tides, rarefying and disturbing
the atmosphere, and in producing disease,
their joint attraction for the earth, or
certain parts of it is greatest; and, on the
contrary where these effects are least evi-
dent, that these attractions are least. Dr.
Mead maintains that the atmosphere is much

more under lunar attraction than the ocean,
124 On the Sanatory and

 

owing to its greater height, which removes
it further from the earth and nearer to the
moon. Dr. Mead supposes that the influ-
ence of the moon is most visible in low
conditions of vitality and in certain states of
disease, and its effects are said to be more
manifest on the nerve force than on theblood,
or any other of the animal fluids. I consider
' it, however, fair that Dr. Mead should, to
a certain extent, be the exponent of his own
views. I therefore make no apology for
quoting, i extenso, two important passages
from his treatise, having special reference
to his theory of lunar influence :-—

“It has been for a considerable time
established that our atmosphere is a thin
elastic fluid, one part of which gravitates
upon another, and whose pressure is com-

municated every way in a sphere to any

~
Physiological Influence of Light. 125

 

given part thereof. From hence it follows
that if by any external cause the gravity
of any one part should be diminished, the
more heavy air would rush in from all sides
around this part to restore the equilibrium
which must of necessity be preserved in
all fluids. Now this violent running in
“of the heavier air would certainly pro-
duce a wind, which is no more than a
strong motion of the air in some determined
direction. If, therefore, we can find any
general cause that would, at these stated
seasons which we have mentioned, diminish
the weight or pressure of the atmosphere,
we shall have the genuine reason of these
periodical winds, and the necessary conse-
quences thereof. The flux and reflux of
the sea was a phenomenon too visible, too

regular, and too much conducing to the
126 On the Sanatory and

 

subsistence of mankind, and all other
animals, to be neglected by those who
applied themselves to the study of nature.
However, all their attempts to explain this
admirable contrivance of infinite wisdom
were unsuccessful till Sir Isaac Newton
revealed to the world juster principles, and,
by a truer philosophy than was formerly
known, showed us how, by the united or
divided forces of the sun and moon, which
are increased and lessened by several circum-
stances, all the varieties of the tides are
accounted for. And since all the changes
we have enumerated in the atmosphere do
fall out at the same times when those
happen in the ocean, and likewise whereas
both the waters of the sea, and the air of
our earth, are fluids subject in a great mea-

sure to the same laws of motion, it is plain
Physiological Influence of Light. 127

 

that the rule of our great philosopher takes
place here—viz., that natural effects of the
same kind are to be attributed as much as
possible to the same causes.* What differ-
ence that known property of the air, which
is not in water, makes in the case, I shall
show anon. Setting aside the considera-
tion of that for the present, it is certain that,
as the sea is, so must our air, twice every
twenty-five hours, be raised upwards toa
-considerable height, by the attraction of the
moon coming to the meridian; so that,
instead of a spherical, it must form itself
‘into a spheroidal figure, whose longest
diameter, being produced, would pass
through the moon. That the like raising

must follow, as soon as the sun is in the

 

* Sir I. Newton’s “ Principia,” p. 387.
128 On the Sanatory and

 

meridian of any place either above or below
the horizon ; and that the moon’s power of
producing this effect exceeds that of the
sun in the proportion of four and a half to
one nearly. Moreover, that this elevation
is greatest upon the new and full moons,
because both sun and moon do then conspire
in their attraction ; least on the quarters, in
that they then are drawing different ways,
it is only the difference of their actions that
produces this effect; lastly, that this in-
tumescence will be of a middle degree at
the time between the quarters and new
and full moon. The different distances of
the moon in her perigeum and apogeum
likewise increase or diminish this power.
Besides, the sun’s lesser distance from the
earth in winter is the reason that the greatest

and least attraction of the air upwards more
Physiological Influence of Light. 129

 

frequently happens a little before the vernal
and the autumnal equinox. And in places
where the moon declines from the equator,
the attraction is greater and lesser alternately,
on account of the diurnal rotation of the
earth on its axis.

«¢ Whatever has been said on this head is
no more than applying what Sir Isaac
Newton has demonstrated of the sea to our
atmosphere ; and it is needless to show how
necesarily those appearances just now men-
tioned of winds, at the stated times, must
happen hereupon. It will be of more use
to consider the proportion of the forces of
the two luminaries upon the air to that
which they have upon the waters of our
globe, that it may the more plainly appear
what influence the alterations hereby made
must have upon the animal body.”

K
130 On the Sanatory and

 

Dr. Mead then proceeds to demonstrate
how much more powerfully the moon in-
fluences the atmosphere than the sea, and
that the tides in the air, from lunar attrac-
tion, are much greater than on those of the
ocean; and, after considering the effect of
certain unnatural states of the atmosphere
upon the barometer, and then the connexion
between certain states of the barometer and
special as well as epidemic diseases, he, in
the subjoined passage, further developes his
views as to the mechanical influence of cer-
tain conditions of the atmosphere on the
respiratory organs :—

“ It will not be difficult to show that these
changes in our atmosphere at high water, new
and full moon, the equinoxes, &c., must oc-
casion some alterations in all animal bodies,

and that from the following considerations :—
Physiological Influence of Light. 131

 

“ st.—All living creatures require air
of a determined gravity, to perform re-
spiration easily and with advantage, for it
is by its weight chiefly that this fluid in-
sinuates itself into the lungs. Now, the
gravity, as we have proved, being lessened
by these seasons, a smaller quantity
than usual will insinuate itself; and this
must be of smaller force to comminute
the blood and forward its passage
into the left ventricle of the heart,
whence a slower circulation ensues, and
the secretion of the nervous fluid is di-
minished.

“‘ ond.—This effect will be the more sure
in that the elasticity of the atmosphere
is likewise diminished. Air proper for re-
spiration must be, not only heavy, but also
elastic to a certain degree; for as this is by

K 2
1g On the Sanatory and

 

its weight forced into the cavity of the thorax
in inspiration, so the muscles of the thorax
and abdomen press it into the most minute
ramifications of the bronchia in expiration ;
where, the bending force being somewhat
taken off, and springy bodies, when un-
bended, exerting their power every way in
proportion to their pressures, the parts of
the air push against all the sides of the
vesicule and promote the passage of the
blood. Therefore, the same things which
cause any alterations in the property of the
air will more or less disturb the animal
motions. We have a convincing instance
of all this in those who go to the top of
high mountains ; for the air is there so pure
(as they call it)—that. is, thin—and wants so
much of its gravity and elasticity, that they

cannot take in a sufficierit quantity of it to
Physiological Influence of Light. 133

 

inflate the lungs, and therefore breathe with
great difficulty.

*3rd.—All the fluids in animals have ,
in them a mixture of elastic aura, whith |
when set at liberty, shows its energy, and |

n

|

the blood and spirits, the excess of which is |

causes those intestine motions we observe i

checked by the external ambient air, while
these juices are contained in their proper
vessels. Now, when the pressure of the
atmosphere upon the surface of our body is
diminished, the inward air in the vessels
must necessarily be enabled to exert its
force in proportion to the lessening of the
gravity and elasticity of the outward ; here-
upon the juices begin to ferment, change
the union and cohesion of their parts, and
stretch the vessels to such a degree as some-

times to burst the smallest of them. This
134 On the Sanatory and

 

is very plain in living creatures put into the
receiver exhausted by the air-pump, which
always first pant for breath, and then swell,
as the air is more and more drawn out;
their lungs at the same time contracting
themselves, and falling so together as to be
hardly discernible, especially in the lesser
animals.”*

Making due allowance for the obsolete
terms used by Dr. Mead, as well as for the
state of pathological and physiological science
of his epoch, the reader will be able to detect,
in the language which he adopts to enunciate
the theory of lunar influence, the germs of
some great truths, which have subsequently
been confirmed, in all quarters of the globe,
by appeals to the great book of nature.
Dr. Mead has undoubtedly laid himself

 

* < Esperienze dell’ Accademia del Cimento,” p. 118.
Physiological Influence of Light. 135

 

open to the charge of attempting to prove
too much; but are not all ardent and zeal-
ous cultivators of science exposed to the
same imputation ?

In the concluding part of the essay, Dr.
Mead details a number of facts that have
come under his own as well as the observa-
tion of his contemporaries, demonstrative of
lunar influence. Some of the cases cited
appear to have a somewhat fabulous origin ;
but making every allowance for some trifling
and natural exaggerations into which the
author has fallen in his zealous endeavours
to substantiate his pet theory, all who read
his essay must admit that it is to a great
extent based on a clear and accurate obser-
vation of facts, however loosely and inaccu-
rately they may have in a few instances,

been recorded. It will be interesting, whilst
136 On the Sanatory and

 

glancing at the literary history of this sub-
ject, to refer to some of Dr. Mead’s illustra-
| tions. Dr. Mead was physician to St.
- Thomas’s Hospital during the time of
Queen Anne’s wars with France, and whilst
occupying this honourable position, a great
number of wounded sailors were brought
into the hospital. He observed that the
moon’s influence was visible on most of the
men at that time under his care. He then cites
_acase, communicated to him by Dr. Pitcairne,
‘of a patient, thirty years of age, who was
subject to epistaxis, whose affection returned
every year in March and September—that
is, at the new moon near the vernal and
autumnal equinoxes. Dr. Pitcairne’s own
case is referred to as a remarkable fact
corroborative of lunar influence. In the

month of February, 1687, whilst at a country
Physiological Influence of Light. 137

 

seat near Edinburgh, he was seized, at nine
in the morning, the very hour of the new
moon, with a violent hemorrhage from the
nose, accompanied with severe syncope.
On the following day, on his return to
town, he found that the barometer was
lower at that very hour than either he or
his friend Dr. Gregory, who kept the
journal of the weather, had ever observed -
it; and that another friend of his, Mr.
Cockburn, professor of philosophy, had died
suddenly, at the same hour, from hemor-’
rhage from the lungs, and also that six of his’ ,
patients were seized, at the same time, with
various kinds of hemorrhages, all arising, e
was supposed, from the effect of lunar
influence on the condition of the barometer.
He refers to the case of a young man, of

delicate habit who brought on an attack of
138 On the Sanatory and

 

hemoptysis by making an effort beyond his
strength. The hemorrhage during eighteen
months regularly recurred at the full of the
moon. ‘Two remarkable instances, illus-
trative of the same fact, are recorded in the

‘* Philosophical Transactions.”* The first

_ is that of a young man who, from his child-

hood till the twenty-fifth year of his age, dis-

| charged a small quantity of blood from the

| corner of the thumb-nail of his left hand,

“every time the moon came to its full. The

other is the case of a patient, who from

‘the fifty-third to the fifty-fifth year of his
age, had a periodical evacuation of blood
‘from the extremity of the forefinger of
‘his right hand.

Baglivi cites the case of a student at

Rome who had a fistulous ulcer of the

 

* Nos, 171 and 172.
Physiological Influence of Light. 139

 

abdomen which appeared to have some
connexion with the colon. This discharged
so abundantly on the increase, and so little
on the decrease of the moon, that it served
him asa perfect index of the periods and
quadratures of that plunet. Nephritic
attacks, he says, frequently follow the
course of lunar attraction.

Tulpius relates that Mr. Ainsworth, an
English clergyman at Amsterdam, constantly
suffered from an attack of the gravel, ac-
companied with suppression of flatus, at the
full of the moon, which continued until she
had made some progress in waning. Van
Helmont mentions this influence of the
moon on asthma; and Sir John Fluyer, who,
from being personally afflicted with this
disease, had more occasion to attend to its

phenomena than most people, asserts that
140 On the Sanatory and

 

paroxysms of asthma are always most
severe at certain periods of the moon, and
commonly recur with the change. Still
more extraordinary effects are attributed to
the lunar influence. The celebrated Kerck-
ringius, in his Anatomical Observations,
mentions the case of a young lady who
became plump and handsome with the in-
crease of the moon, but who completely
changed with the decrease of that planet.
About the change, she became so disfigured
and haggard that she secluded herself from
all society for some days. Mead also refers
to a lady, whose countenance always de-
veloped itself with the increase of the moon,
so that the éclat of her charms always de-
pended upon that planet.

Having given the preceding sketch of

Dr.:Mead’s essay, I now proceed to analyse
Physiological Influence of Light. 141

 

Dr. Balfour's treatise, the second work of any
importance specially devoted to this subject.
Dr. Francis Balfour’s first dissertation
appeared in Calcutta, in 1784.* In 1790,
in a “ Treatise on Putrid Intestinal Re- |
mitting Fevers,” published at Edinburgh,
the periodical return of febrile paroxysms
and their coincidence with the periodical re-
volutions and remissions of sol-lunar power,
which constitutes the foundation and proof
of this theory, was investigated, described,
and illustrated by two different plates, ex-
hibiting a synoptical view of the whole
system. ‘The first part of that treatise is a
regular logical synthesis, arising from facts

observed and collected by himself to the

 

* “Treatise on the Influence of the Moon in Fevers.”
This was subsequently reprinted in England, and in-
serted in Dr. Duncan’s “ Medical Commentaries.”
142 On the Sanatory and

 

discovery of certain prevailing tendencies in
nature, and thence to axioms or general
laws. The second part is an analysis, in
which these axioms or laws are employed to
explain some of the most remarkable phe-
nomena of fevers. The third part is an
application of the principles of this theory
to form general rules for practice.

This physician appears to have devoted
great attention to the consideration of this
subtle and disputed point in science, and,
with a view to its satisfactory elucidation
placed himself in communication with all
the medical men of note resident in our
Indian presidencies, eliciting from them the
result of their observations on the subject.
Dr. Balfour maintains, that every type of

fever prevalent in India is, in a remarkable
Physiological Influence of Light. 143

 

manner, affected by the revolutions of the
moon. Whiutever may be the form of
fever, he says that he has invariably ob-
served that its first attack is on one of the
three days which immediately precede or
follow the full or the change of the moon, so
that the connexion which prevailed between
the attack of the disease and the moon at
or during the time referred to, was most
remarkable. Relapses in cases of fever are
also said frequently to occur at such times.
Dr. Balfour has observed for a period of
fourteen years, this tendency to relapse at
the lunar full and change ; and, in particu-
lar cases, he was able to prognosticate the
return of the fever at these periods with
almost as much confidence as he could fore-

tell the moon’s revolution itself. Putrid,
144 On the Sanatory and

 

nervous, and rheumatic fevers of India are,
according to Balfour, equally under the
influence of the moon. In attempting to
explain these phenomena, Dr. Balfour says,
that along with the full and change of the
moon there is constantly recurring some un-
common or adventitious state or quality in
the air which increases fever and disposes
to an unfavourable termination or crisis ;
and that along with the intervals there is
constantly recurring a state or quality in the
air opposite to the former, which does not
excite but diminishes fever and disposes

to a favourable crisis.* Dr. Balfour has

 

* It will be well to state what Dr. Balfour means by a
crisis. He defines it to be “favourable changes which
never fail to take place, in some degree or other, at the
time of their transition from the lunar period in the inter-
lunar interval, and generally on the first morning inter-
meridional interval after it; at which juncture the
Physiological Influence of Light. 145

 

collected a vast body of valuable evidence
in support of his lunar theory, establishing
beyond all dispute that in tropical climates
the regular diurnal and septenary changes
observed in the character of the fevers of
India are coincident and correspondent with
periodical sol-lunar conditions.

In the year 1783-4, Dr. Balfour had for
many months the charge of a regiment of
sepoys, in Cooch Behar, immediately under

the vast range of mountains which eepanates

 

maturity of the critical disposition concurs with the
periodical decline of sol-lunar influence in bringing them
about; and they are distinguished by one or more of '
the following symptoms—viz., a sediment, or particular
turbid. appearance, of the renal secretion ; a more free and
natural perspiration; spontaneous evacuations; and cleaner,
moister, and softer tongue, with amore free and natural
discharge of saliva, a more loose and copious expectora-
tion, and a free discharge of bile, which seems to disappear
and be suppressed in the course of the fever,” &c.

L
146 On the Sanatory and

 

the northern part of Bengal from Bootan.
' The prevalent diseases were fevers, or
“< fluxes” attended with fevers. During
‘the first month four hundred men were
Linvalided. The greater part, however, of
these cases were convalescent in the course
of the eight days that intervened between
the full and change of the moon; but
during the remaining months of his stay in
that district, the diseases previously men-
tioned increased to almost double their
extent at every full and change of the moon,
falling down again to their former standard
during the eight days which intervened
between these two periods. With regard
to small-pox occurring in India, Dr. Bal-
four expresses himself as perfectly satisfied
‘that the full and change of the moon

interfered with the eruption, and increased
Physiological Influence of Light. 147

 

the accompanying fever to a dangerous
degree.

Mr. Francis Day, of the Madras army,
thus generalizes Dr. Balfour’s observations:

1. That the influence of the moon is less
apparent in Madras than in Bengal, but
may be traced over every portion of our
Eastern possessions.

2. That the lunar influence is thus
exerted :—The first attack of fever almost
invariably commences on one of those days
preceding the full or new moon, or on one of
those three which immediately follow them,
but that the last three are the most violent
in their effects.

3. That the new moon is more injurious
than the full.

4. That during these times the most
severe as well as the greatest number of

La
148 On the Sanatory and

 

cases take place, but that when they occur
at other periods they are less severe, and of
short duration.

5. That these laws are as applicable to
relapses as they are to primary attacks ; so
much so, that the author was often able to
prognosticate the return of the fever at these
periods with almost as much certainty as he
could foretell the revolution (of the moon)
itself.

Mr. Day epitomises the results of care-
fully prepared statistical observations as
follows:—

1. That no decided preponderance in the
admissions for malarious fever is observed
‘at the time of the new moon.

2. That a decided preponderance is ob-
served at the time of the full moon.

3. That more admissions occur in the
Physiological Influence of Light. 4g

 

three days preceding the full moon than in
the three days subsequent to those changes.

4. That aslight increase in the admissions
may be present about the first and third
lunar quarters.

5. Uhat the cases admitted at the time of
the new moon are generally slightly more
severe than the average admissions.

6. That the cases admitted at the time of
full moon are much more severe than the
average admissions.

7. That at times increased severity is
also apparent at the first and third lunar
quarters.

8. That the cases admitted during the

nr

three days preceding these changes are more |

severe than those admitted in the three '

subsequent ones.

From the entire series of cases, Mr. Day
150 On the Sanatory and

 

arrives at the probability that there is a
7 sol-lunar influence which is ‘greater in the
" equinoctial period than in the respective
equinoctial intervals, and considerably
more so in the autumn than in the vernal
equinoctial period ; that this force is greater
at the full and new moon than at the
intervals, and much more so at the full
than at the new; that it is greater during
the meridional period than at the intermeri-
dional intervals, and much more so at the
diurno-meridional than at the nocturno-
meridional periods.*

The influence of the moon on the func-

i

‘tions of life has been made the subject of

 

* Quoted from Sir J. Ranald Martin’s valuable work
on the “Influence of Tropical Climates in producing

the Acute Endemic Diseases of Europeans.” London,
1861.
Physiological Influence of Light. 151

 

observation and speculation in every part of
India. The physiological and pathological
effects of lunar light have been universally
acknowledged by all medical men practising
in tropical climates. The natives of India
are taught to believe in lunar influence from
early infancy. In the northern latitudes
the effects of the moon’s rays are said to
be less sensibly felt than in India. In
the latter country, those suffering from
attacks of intermittent fever are often
able to predict, by watching the phases of
the moon, the accession of the disease.
Balfour maintains that the fact of diseases
appearing during every day of the month
is no legitimate argument against lunar
influence.

‘© The human body,” he says, “is sub-

ject to alterations from a thousand external
152 On the Sanatory and

 

physical circumstances as well as from many
internal moral affections. These lay the
foundation of disease at every period of life,
but they do not overthrow the evidence of
lunar influence, although they are apt to
mislead with regard to effects that depend
‘on that alone. The human body is affected
in a remarkable manner by the changes of
the moon, I am perfectly convinced,
although I cannot constantly pretend to see
the operation of the general law, nor to
account at all times for its perturbation, and
agree in thinking that an attention to the
power of the moon is highly necessary to
the medical practitioner in India.”

“It is a fact,” says Dr. Orton, “ which
has been universally observed, particularly
in tropical climates, that the moon has a

great influence on the weather; the full
Physiological Influence of Light. 153

 

and change tending to produce rain and
storms, and the quarters being more fre-
quently attended by fine weather.” This is
so well ascertained, and so thoroughly
believed, at least in India, that it is nearly
superfluous to adduce arguments or in-
stances in support of it. On every side,
then, we perceive the intimate connexion
which exists between the three series of
phenomena which have been noticed—the
great lunar periods, disturbed states of the
atmosphere, and the attacks of the epidemic. |
It will also be proved that the other prin |
cipal circumstance which has been supposed
to attend the prevalence of cholera, the de-
pression of the barometer, is likewise pro-
duced by the new and full moon. Dr.
Orton says, “ Sol-lunar influence is, doubt-

less, but one of the causes producing the
154 On the Sanatory and

 

state of the atmosphere which gives rise to
cholera; and I have no doubt that the
disease will often be found to make its
appearance when the disturbing power of
the sun and moon is least, and to subside
when that power is at its height. General
exacerbations of other epidemics, as well as
of cholera, will usually be found to corre-
spond to the moon’s syzygies, and the
remissions of the quarters.”

Dr. Kennedy bears testimony, in his
-work on Epidemic Cholera, to the influence
of the moon. He observes, “that the
constitution here (India), both native and
denizen, is assuredly under lunar in-
fluence, or, what is the same thing, under
the influence of the changes of weather
which invariably accompany the changes

of the planet.”
Physiological Influence of Light. 155

 

Diemerbroeck, in his well-known treatise |
on the Plague,* when speaking of the,
epidemic of 1636, says: “ Two or three
days before and after the new and full
moon the disease was more violent ; more
persons were seized at these times than at |
others, and those who were then seized
almost all died in a very few hours.
Nescio qua virium labefactione oppressi.”
In the dedication prefixed to this treatise,
which is addressed to the pretor and
consuls and the whole senate at Utrecht,
he thus describes the nature of his own
situation, the opportunities he had of ac-
quiring a knowledge of the disease, and his
object in publishing the work :—

 

* “Tsabrandi Diemerbroeck Montferto Trajectini,
antehac Noviomagi, nunc Ultrajecti Medici, de Peste.”
Libri Quatuor Dissertatio, kc. Arenaci, 1646.
156 On the Sanatory and

 

«As in all well-constituted states it is
the duty of every one to contribute his
advice and assistance for the public safety,
that by their unanimous concurrence the
present as well as impending evils of the
state may be averted and repelled, I con-
ceive that I should not act improperly if,
concerning this plague, of all diseases the
most cruel, and more destructful than an
enemy, I, too, should offer some salutary
advice toward the discovery of its hidden
nature, together with some more certain
method of curing it. For, as in warfare,
none can so well elude the designs of the
enemy, or repel his attacks, as one who has
had experience in the art of war, so none
can more effectually resist this cruel disease
than one who has intrepidly opposed him-
self to its fury. This I did a long time
Physiological Influence of Light. 157

 

ago, not only in the year 1633, when a
most violent pestilential fever, the fore-
runner of this plague, afflicted most grie-
vously the whole province of Gelderland,
and principally the city of Nimeguen, where
I was ordinary physician, and threw upon
me so great a load of practice as hardly
allowed me to take sustenance, but likewise,
in 1636 and 1637, when the true plague
raged so violently amongst the people of
Nimeguen, and so great a number of sick
was thrown upon my hands as to give
me no rest or repose. Having at that
time, with great danger, and at the risk
of my life, investigated most inquisi-
tively the nature of this most dreadful
enemy, I now make public his portrait,
delineated in this book, for the safety
of all.”
158 On the Sanatory and

 

The same writer asserts that during the
epidemic fever which raged in Italy in
1643, patients died in great numbers on the
a1st of January, at the period of the lunar
eclipse. But as Dr. Lardner observes,
when recording the fact, it may be objected
that the patients who then died in such
numbers at the moment of the eclipse
might ‘have had their imaginations highly
excited, and their fears wrought upon, by
the apprcach of that event, if popular
opinion invested it with danger. That
such an impression was likely to prevail is
evident from the facts which have been
recorded. In 1654, at the time of a solar
eclipse, such was the strong opinion enter-
tained on this subject, that patients in con-
siderable numbers were ordered by their

physicians to be shut up in chambers well
Physiological Influence of Light. 159

 

closed, warmed, and perfumed, with the
view of escaping the injurious influence of
the eclipse. The consternation that pre-
vailed amongst all classes was very great,
and such crowds rushed to the confessional,
that the ecclesiastics found it impossible to
exercise their spiritual vocations.

The late Dr. James Johnson observes,*
whenalluding to the fevers of India, however
sceptical professional men in Europe may
be in regard to planetary influence in fevers,
&c., it is too plainly perceptible between
the tropics to admit of a doubt. ‘I have,”
he continues, “not only observed it in
others, but have felt it in my own person
in India when labouring under the effects
of obstructed liver. That this influence

predisposes to, or exacerbates, the parox-

 

* © On the Diseases of Tropical Climates.”
160 On the Sanatory and

 

ysms of fever in India and other tropical
climates is incontestably proved by daily
observation.”

Dr. Scott, when speaking of the effect
of sol-lunar light on the endemic and epi-
demic diseases prevalent on the western side
of India, says, “ The influence of the moon
on the human body in this part of India is
observed by every medical practitioner. It
is universally acknowledged by the doctors of
all colours, castes,and countries. The people
are taught to believe in the fact in their
infancy, and as they grow up they acknow-
ledge it from experience. I suppose in the
northern latitudes this power of the moon
is far less sensible than in India. We here
universally think that this state of the
weakly and diseased bodies is much influ-

enced by the movements of the moon.
Physiological Influence of Light. 161

 

Many people know the very day on which
their intermittents will make their appear-
ance; and every full and change increases
the number of patients of every practitioner.
It is no argument against this influence that
diseases appear during any day of the
month. The human body is subject to
alterations from a thousand circumstances,
and from many affections of the mind.
These lay the foundation for disease at
any period; but they do not overthrow
the evidence of lunar influence, although
they are apt to mislead with regard to that
alone.”

Mr. Hutton, writing to Dr. Balfour from
Calcutta, says that he has been at some
pains during a considerable practice of some
years at Prince of Wales Island to observe
the effects of the moon on the prevailing

M
162 On the Sanatory and

 

diseases of that place. The diseases peculiar
to that island are of the intermitting and re-
mitting kind, dysenteries, diarrhceas, liver
complaints, and rheumatic affections. “I
have,” he adds, ‘‘ generally found the vio-
lence of the symptoms (in the above men-
tioned diseases) considerably increased
during the full and change of the moon.
I have noticed relapses to occur from the
same cause. By keeping these facts in
view, I have been enabled to administer the
medicine adapted to the different diseases
with a.greater degree of certainty and pre-
cision.”

Dr. Moseley remarks that the greater
hemorrhages from the lungs or those of
plethora, like all periodical attacks of this
kind (undisturbed in their natural course by

peculiar circumstances), obey the influence
Physiological Influence of Light. 163

 

of the moon. Of this, he says, he has had
many proofs. That there are not more
authenticated by others is owing, he be-
lieves, to the theory on which the fact
depends not being sufficiently known to
prevent the result escaping unnoticed. In
another portion of his work he remarks
that most of the patients whom he had
attended in the spring of the year 1777
during attacks of fever were much affected
in the head at every new and full moon.
He refers to the case of a man who had
a severe attack of hemoptysis always at the
moon's full. When speaking of the mode
of treating these hemorrhagic conditions,
he advises the physician to be watchful in
every case of the kind when the moon’s
influence was considered to be greatest on
the earth. He cites the history of a gentle-

M2
164 On the Sanatory and

 

man who suffered from hemorrhage of the
lungs, who was advised to leave England
during the winter and to reside in the south
of France. Whilst there his attacks came
on periodically, obeying faithfully the prin-
cipal changes of the moon. Dr. Moseley
considers. this to be one of the most
decisive examples of lunar influence re-
corded in medical history. The following
particulars of his illness deserve attentive
consideration.

On February 14th, 1786,when near Toulon,
hemorrhage came on; the moon was at its
full on the preceding day. On February
agth, when at Aix in Provence, he had
another attack, There was a new moon on
the 28th. The moon was again at its full
on the 13th of April, and on the 15th the
patient had another attack of hemoptysis.
Physiological Influence of Light. 165

 

A new moon appeared on the 28th of the
same month, and on the 29th, when at
Tain upon the Rhone, he had a relapse.
At Chalons, in Burgundy, there was a full
moon on the 13th of May, and on the 14th
his hemorrhage returned. At Dijon, June
11th, when the moon was at its full, he had
another attack. On July 11th, at Paris,
the moon was again at its full. At this
lunar period the hemorrhage returned.
Again, when at Yarmouth in the Isle of
Wight, on August 9th, the moon was then
at its full. The hemoptysis returned. Dr.
Moseley alludes to the remarkable fact that
the last three attacks of hemorrhage from
the lungs came on at the instant the moon

appeared above the horizon.*

 

* Dr. Moseley has pursued, in a few particulars,
these investigations to an extreme point. I say so with-
166 On the Sanatory and

 

Nicholas Fontana says, “that the in-
fluence of the moon is very visible in almost.
all febrile cases. I had a good opportunity
of observing this fact in my first voyage to
this country (Barrackpore), in the year 1777,
and subsequently on board the Liverpodl
East Indiaman. The ship was driven on a
bank in the river Massuma, on the east
coast of Africa, at a place called Behagoa
Bay. The crew, through hard labour and the

 

out intending for a moment to throw discredit on his
general statements. He asserts as a positive fact that
persons who live to an extreme age, invariably die at the
new or at the full moon. After citing a number of
instances illustrative of this opinion, he remarks, “ Here
we see the moon shines on all alike, making (as in death)

no distinction of persons in her influence :”—

 

Ke quo pulsat pede pauperum tabernas

Regumque turres.”
Hor. lib. 1, 4.

—“A Treatise on Tropical Diseases.” By B. Moseley,
M.D. 1792.
Physiological Influence of Light. 167

 

unwholesomeness of the place, suffered much
from epidemic bilious fever. We had 60 or
“o patients ill out of the crew of 180.
Every one was seized with illness, and
several died. In the Gulf of Cambay, at
the Nicobar Islands, at Kedgeree, in the
River Ganges, Houghly, and on our
return to St. Jago, one of the Cape de
Verde Islands, where the ships went, and
remained a certain time in the course of the
voyage, the crew was severely and re-
peatedly attacked with remittent and inter-
mittent fevers.

“T observed, and was so fully persuaded of
the effects of the moon’s changes on them
that I took notice of the fact in a work I
published after my return from Italy. I
did so with the view of cautioning succeed-

ing surgeons coming from the Mediterranean.
168 On the Sanatory and

 

In that country the method adopted in
our practice was by no means fitted to
the treatment of the acute diseases which
Europeans were liable to between the
tropics.”

“Daily practice,” says a well-known
army surgeon, Dr. Millingen, ‘‘ shows that
paroxysms of fevers and various other
maladies are under planetary influence.
The evening gun in our garrisons was often
the signal of severe exacerbation in certain
febrile cases, while the réveil/ée developed
acute aggravation in others.” Sydenham
and Floyer remark that gout and asthma
were usually ushered in after the first sleep ;
and that during the prevalence of the
cholera the invasion of the disease was
noticed to occur towards daybreak.

The authorities previously cited conclu-
Physiological Influence of Light. 169

 

sively establish that lunar influence is not to
be viewed as a mere myth, or as an utopian
speculation. A host of intelligent writers
and acute observers confirm the fact beyond
all dispute. It will remain for me to con-
sider, not only the evidence in favour of the
lunar theory, but the arguments advanced
against the hypothesis. It is only by closely
investigating both sides of the question that
the philosopher in search of truth will
be enabled to arrive at a safe deduc-
tion.

Before considering the effect of the moon
upon the mind in a state of aberration it
will be necessary to revert to the morbid
and physiological effect of lunar light upon
the vegetable kingdom. This has long
been the subject of observation and specu-

lation. Many curious and apparently inex-
170 On the Sanatory and

 

plicable facts are upon record illustrative of
the phenomena. It will be well to refer
to some of the more reliable data in
connexion with this division of my sub-
ject; but before doing so, I would remark
that the Druids of Gaul and Britain, who
combined the office of physician with
that of the priest, believing with the ancients
that all vegetable productions, and par-
ticularly medicinal plants, were constantly
under planetary influence, were instructed to
gather the far-famed mistletoe with a golden
knife when the moon was six days old.

It is a question whether the vervain of
the ancients was similar to the plant which
now bears that name. The appellation Ver-
bene or Sagmina was given by the ancients to
various plants used in religious ceremonies.

The vervain, held in such high repute by

the Romans, was gathered after libations of
Physiological Influence of Light. 171

 

honey and wine at the rising of the dog
star, and with the left hand, and, thus col-
lected, served for various sacerdotal and
medicinal purposes. Its branches were em-
ployed to sweep the temples of Jupiter ; it
was used in exorcisms for sprinkling. lustral
water; and, moreover, it was said to cure
fevers, the bite of venomous reptiles, and it
was alleged to have the virtue of allaying
discord, and appeasing other violent passions.
This plant so gathered was always carried in
the hand byheralds when sent to sue for peace.
It was called Verbenarii. When its benign
powers were shed over the festive board
mirth and good temper were said to prevail.

When speaking of the all-powerful in-
fluence of this plant, Pliny says—

“ Nulla herba Romana nobilitatis plus habet quam

hierabotane.”*

 

* Plinii, lib. 18, c. 44.
172 On the Sanatory and

 

It is stated as a fact that if peas are sown in
the increase of the moon they never cease
blooming ; that if fruits and herbs are set
during the wane of the moon, they are not
so rich in flavour, nor so strong and healthy,
as when planted during the increase. All
vines should be pruned at the wane of the
moon, says Sibley, the astrologist. He also
asserts that pomegranates will live only as
many years as the moon was days old when
they were planted. In planting shrubs, if they
are desired to shoot up straight and late,
and to take little root, they are to be set
when the moon is in an airy sign, and in in-
creasing light. Flowers that are under the
influence of the moon only open their
blossoms at night, whilst those that are
peculiarly under the government of the sun

open every morning when it begins to rise,
Physiological Influence of Light. 173

 

and close in the evening when he sinks
below the horizon. M. Auguste de Saint-
Hilaire states, that in Brazil, cultivators
plant during the decline of the moon, all
vegetables whose roots are used as food ;
and, on the contrary, they sow during the
increasing moon the sugar-cane, maize, rice,
beans, &zc., and in general those which bear
the food upon their stocks and branches.
Experiments, however, were made and
reported by M. de Chanvalon, at Martinique,
on vegetables planted at different times in
the lunar month, and no appreciable diffe-
rence in their qualities was discovered.
There are some traces of a principle in the
rule adopted by the South American
agronomes, according to which they treat
the two classes of plants distinguished by

the production of fruit on their roots or on
174 On the Sanatory and

 

their branches differently ; but there are
none in the European aphorisms. The
directions of Pliny are still more specific :
he prescribes the time of the full moon for
sowing beans, and that of the new moon for
lentils. ‘ Truly,” says M. Arago, “we
have need of a robust faith to admit, with-
out proof, that the moon, at the distance of
240,co0 miles, shall, in one position, act
advantageously upon the vegetation of
beans, and that, on the opposite position,
and at the same distance, she shall be pro-
pitious to lentils.” The wise husbandman
is said to prune his vines in obedience to
certain phases of the planet. It is a maxim
amongst gardeners that cabbages and lettuces
which are desired to shoot forth early,
flowers which are to be double, trees which

it is desired should produce early ripe
Physiological Influence of Light. 175

 

fruit, should severally be sown, planted,
and pruned during the decrease of the
moon; and, on the contrary, that trees
expected to grow with vigour should
be sown, planted, grafted, and pruned
during the increase of the moon. These
opinions Dr. Lardner considers to be
altogether erroneous. The increase or de-
crease of the moon, he maintains, has no
appreciable influence on the phenomena of
vegetation ; and the experiments and obser-
vations of several French agriculturists, and
especially of M. Duhamel du Monceau,
have, he observes, clearly established this
act;

Mantanari has referred to physical causes
for an explanation of the alleged lunar
influence upon plants. During the day, he

says, the solar heat augments the quantity
T6 On the Sanatory and

 

of sap which circulates in plants, by increas-
ing the magnitude of the tubes through
which the sap moves, while the cold of the
night produces the opposite effect by con-
tracting these tubes. Now, at the moment
of sunset, if the moon be increasing, it will
be above the horizon, and the warmth of
its light would prolong the circulation of the
sap ; but, during its decline, it will not rise
for a considerable time after sunset, and the
plants will be suddenly exposed to the un-
mitigated cold of the night, by which a
sudden contraction of leaves and tubes will
be produced, and the circulation of the sap
as suddenly obstructed. This explanation
does not satisfy Dr. Lardner, who remarks,
that if it be admitted that the lunar rays
possess any sensible calorific power, this

reasoning might hold good, but it will have
Physiological Influence of Light. 177

 

very little force when it is considered that
the extreme change of temperature which
can be produced by the lunar light does
not amount to the thousandth part of a
degree of the thermometer! Upon this
point, however, philosophers are at variance.
The lunar rays, have, according to the ex-
perience of practical men, a decided calorific
effect.

The gardeners of Paris assured Arago that
in the months of April and May they found
the leaves and buds of their plants, when
exposed to the full moon in a clear night,
actually frozen, when the thermometer in the
atmosphere was many degrees above freezing-
point. He mentions these facts as proving
that the moon’s rays have a frigorific power,
but that the largest speculums directed to
the moon produced no such indications ona

N
198 On the Sanatory and

 

thermometer placed in their focus.* Dr.
Howard, of Baltimore, has affirmed that on
placing a blackened upper ball of his
differential thermometer in the focus of a
thirteen-inch reflecting mirror opposed to
the light of the full moon, the liquor sank,
in half a minute, eight degrees ! Though
the surface of the full moon exposed to us
must necessarily be very much heated, says
Sir J. Herschel, possibly to a degree much
exceeding that of boiling water—yet we
feel no heat from it, and even in the focus
of large reflectors it fails to affect the
thermometer. No doubt, therefore, its
heat (conformably to what is observed of
that of bodies heated below the point of
luminosity) is much more readily absorbed

in traversing transparent media than direct

 

* Ferguss. “ Bull. Univ.” 1827, p. 383.
Physiological Influence of Light. 179

 

solar heat, and is extinguished in the upper
regions of our atmosphere, never reaching the
surface of the earth at all. Some proba-
bility is given to this by the tendency to
disappearance of clouds under the full
moon, a meteorological fact (for as such we
think it fully entitled to rank), for which
it is necessary to seek a cause, and for which
no other rational explanation seems to offer.*

Cases of sudden death and profound
coma are recorded as the effect of an im-
proper and prolonged exposure to the
intense light of the full moon. Sailors have
been found dead on deck after sleeping
under the moon’s rays. It is also said that.
convulsions, apoplexy, epilepsy, and in-
sanity, sensations of oppression in the head,

inertness and heaviness of the senses, have

 

* Outlines of Astronomy, pp. 261, 2. 1849.

N 2
180 On the Sanatory and

 

arisen from the same cause. Plutarch
observes :—‘ Everybody knows that those
who sleep abroad under the influence of the
moon are not easily awakened, but seem
stupid and senseless.”* In India, death has
occasionally been known to arise from what
is termed a coup de lune, or stroke of the
moon ; and in Egypt, blindness has often
been produced in persons who have impru-
dently fallen asleep with their faces exposed
to intense lunar light. Does not Edgar
Allan Poe refer to this morbid effect of the
moon’s rays in the following passage ?—

“Neath blue bell or streamer,
Or tufted wild spray,
That keeps from the dreamer
The moonbeam away.”

 

* Plut. “Symp.” B. 3.
+ “Al Aaraaf.” Tycho Brahe suddenly discovered in the
heavens a star which attained ina few days a brilliancy sur-
Physiological Influence of Light. 181

 

Dr. Madden mentions that the Arabs
attribute a morbid influence to the moon,
and think it causes ophthalmia and catarrh.
He thought there was some influence from
it in the desert beyond the common damp-
ness of the night.*

The questions that naturally occur to the
mind in reference to this interesting inquiry
are, whether the morbid phenomena alleged
to result from the moon’s rays are dependent
upon the mere intensity of lunar light, or are
to be considered as the effect of some specific
influence in the nature of the light itself ?.
Let me consider the first question. It is an
admitted fact that the light of the full moon

 

passing that of the planet Jupiter, and then as quickly
disappeared! ‘This phenomenon gave origin to the poem
referred to.

* “Travels in Turkey.”
182 On the Sanatory and

 

is at least 300,000 times more feeble than that
of the sun. According to Humboldt, the
mean distance of the earth from the sun is
12,032 times greater than the earth’s dia-
meter, therefore 20,682,000 German or
82,728,000 English geographical miles. The
mean distance of the moon from the earth is
51,800 German or 207,200 English geogra-
phical miles.*

It is said that the solar light reflected from
the surface of the moon is in every zone
fainter than the solar light reflected in the
daytime from a white cloud.+

When estimating the intensity of lunar
light, Sir John Herschel affirms, that in the

 

* Cosmos.

+ Sir J. Herschel says that it appears to be placed
beyond a doubt that the moon acts directly as a magnet
on the earth’s magnetism, producing periodical fluctuations
in the latter of extremely small amount.
Physiological Influence of Light. 183

 

southern hemisphere the moon is 27,408
times brighter than a Centauri, which is third
in brilliancy of all the stars. In our own cli-
mate the light of the moon is said to be 3000
times greater than that of the planet Venus.

Planetary light requires fourteen minutes to
cross the earth’s orbit. According to Bradley,
the light of the sun takes eight minutes to
reach the earth. Reckoning the mean dis-
tance of the sun to be 94,874,956 miles from
the earth, it follows that light traverses
the air with a velocity of about 200,000

miles per second.* ‘Robins states that a

 

* One hundred and eighty thousand miles per second
according to Herschel’s calculation, that is go1,000 times
faster than sound, which travels at the rate of 1ogo feet per
second, or nearly thirteen miles ina minute. Were the sun
and the earth connected by an iron bar, 1074 days, or
nearly three years, must elapse before a force applied at the
sun could reach the earth. With a bar of tin, nearly seven.
years would be necessary. A writer in the “Quarterly Re-
184 On the Sanatory and

 

twenty-four-pounder with a common charge
of powder discharges its ball with an initial
velocity equal to 1600 feet per second. If
such a ball were to continue its velocity
undiminished, it would require about te
years to traverse a span, which the light of
the heavenly bodies pervades in eight
minutes !

Humboldt, when speaking of this subject,
remarks :—‘ When taking lunar distances

from the sun for determinations of geogra-

 

view” has placed this remarkable property of matter in a
popular and paradoxical aspect, by imagining Titan and
Saturn placed in opposite points of the orbit of the planet
which bears the name of the latter, and their ancient com-
bats being resumed with weapons of earthly fabric, thedeadly
blow dealt by the former would not slay its victim till
after the lapse of fifty-two years; and if, one year before
this event, Saturn should aim a mortal thrust at his
antagonist, it could not prove fatal till ffty-one years after
his own death!
Physiological Influence of Light. 185

 

phical longitude, it is not unfrequently
found difficult to distinguish the moon’s
disk amongst the more intensely illuminated
cumuli. On mountains between 13,000 and
17,000 feet high, where in the clearer moun-
tain air only light, feathery, cirrous clouds
are to be seen, I found it much easier to
distinguish the moon’s disk ; both being
cirrous, from its slighter texture, reflects
less of the sun’s light, and the moon loses
less in passing through the thin atmospheric
strata.” The ratio of the intensity of the
sun’s light to that of the full moon deserves
further investigation, as Bouguer’s generally

received determination, 5,,'5o,, differs so

 

strikingly from the indeed more improbable

 

one of Wollaston, s5)555-  Wollaston’s
comparison of the light of sun and moon,

made in 1799, was based on the shadows
186 On the Sanatory and

 

cast by wax-light, while in the experiments
with Sirius, in 1826-27, images reflected
from a glass globe were employed. The
earlier assigned ratios of the intensity of
solar light as compared to that of the moon
differ very much from the results here
given. Michel and Euler, proceeding from
theoretical grounds, have respectively con-
cluded 450,000 and 374,000 to 1. Bou-
guer, from measurements of the shadows of
wax-lights, had even made it only 300,000
to I.

I think, after duly weighing the above
facts, we must dismiss from the mind the
impression that the intensity of the light of
the moon, as compared to that of the sun,
has any relation to the supposed morbid
effect of lunar light.

I proceed, in the next place, to the con-
Physiological Influence of Light. 187

 

sideration of the questions, whether the
alleged morbid effect of lunar rays is attri-
butable to something specific in the com-
position of the light itself; and secondly,
whether the supposed abnormal influence of
the moon is not altogether owing to certain
barometrical variations and meteorological
phenomena consequent upon the phases
or position of the planet. Is there
anything specific in the composition of
lunar light ?

According to numerous observations
which Arago made with his polariscope,
the moon’s rays contain polarized light
which carbonizes, and is therefore antago-
nistic to the sun’s rays, which oxygen-
ate. The polarization of light was not dis-
covered until five years before the death of

Huyghens, viz., in 1690. It has, however,
188 On the Sanatory and

 

been stated that the phenomenon was recog-
nised in 1665, by Grimaldi and Hooke.

When a polarized ray is passed through
a thin slice of transparent substance, its
effect is said to be most remarkable. ‘Its
whole molecular constitution,” says Mr.
Hunt, “‘ appears revealed, as if by the touch
of a magic wand. ‘The surfaces of many
substances, such as thin films of sulphate of
lime or mica, become painted with the most
beautiful colours, By turning the plate of
the polariscope round, these can be made to
dissolve or reappear in an exceedingly sin-
gular manner. Rings of the most charming
colours are seen in some substances, and
these are marked with a figure resembling a
Maltese cross in black and white.

Polarized light has been used by chemists

for the purposes of making subtle analyses of
Physiological Influence of Light. 189

 

certain articles of food. M. Biot has applied
the rays of polarized light to sugar with the
view of ascertaining the existence of adulte-
rations. It is easy by means of the polari-
scope to distinguish between sugar made
from beet-root and that manufactured from
the sugar-cane.*

What is polarized light? Sir David
Brewster thus lucidly explains the pheno-
menon: When the ray of light falls on a
transparent body, so as to be reflected from
it, it is modified or affected in such a manner
by this reflection, that upon meeting a second
transparent body, it will either be reflected
or not, according to the side which it pre-
sents to it. It will be reflected if it fall
upon that body on either of the opposite
sides, but will not be reflected if it fall upon

 

* Hunt on Light.
190 On the Sanatory and

 

either of the other two, at right angles to
the former. Thus, suppose the ray, after
being modified by the first transparent re-
flector, presents itself to the second, so as to
be reflected, and call the side of the ray, on
which it meets the second reflector, on the
north side ; if the second reflector is turned
round, so that the east side of the ray meets
it, there will be no reflection, and in like
manner it will be reflected on the south and
not on the west sides respectively. The
same modification, whatever it may be,
prevents the ray from being doubly refracted,
by passing through Iceland crystal, which it
meets on two of its opposite sides, but per-
mits it to be doubly refracted by meeting
the crystal on the two other sides. And
this modification, with respect to double

refraction, may. be impressed upon the ray
Physiological Influence of Light. 191

 

by a first double refraction, as well as by
reflection from a transparent body. But
where the modification is produced by reflec-
tion, it is most complete at one particular
angle of incidence, which varies in different
transparent substances.

Now, the existence of this phenomenon
is certain; it is a fact that a change takes
place in the ray by the operation of the
first transparent body ; itis a fact that this
change has some kind of reference to the
four sides of the ray, and affects those sides
at right angles to each other differently.
The observers of these appearances have
explained them, by supposing that each
particle of light has its adjacent sides en-
dowed with opposite properties, and that
the first reflecting, or double refracting

body, turns or arranges all the particles of
192 On the Sanatory and

 

light in aray, in such a manner that their
similar sides are presented in the same di-
rection to the second body. Now this
arranging or turning of the particles, or
this change operated by the first body upon
the ray, whatever it may be, is termed,
from analogy to the phenomena of mag-
netism—polarization.*

Having cursorily referred to two modes
of explaining the morbid phenomena of
moonlight, I have yet to consider the most
rational and philosophic theory of lunar
influence propounded—viz., the effect of
the moon’s position upon the wind, tempera-
ture, and rain, three meteorological con-
ditions universally admitted to play an
important part in the origin, spread, and

modification of disease. It has been a

 

* “On Optics,” by Sir David Brewster.
Physiological Influence of Light. 193

 

vexed question with natural philosophers,
whether the barometer is decidedly influenced
by the phases of the moon. ‘The facts
illustrative of this point are too significant
to justify a doubt upon the question.

A remarkable correspondence between
the phases of the moon and certain states.
of the barometer has been observed by
Luke Howard. This coincidence, he main-
tains, consists of a depression of the baro-
metrical line on the approach of the new
and full moon, and its elevation on that of
the quarters. In above thirty out of fifty
lunar weeks in one year, the barometer was
found to have changed its general direction
once in each week, in such a manner as to
be either rising or at its maximum for the
week preceding and following about the
time of each quarter, and to be either fall-

Oo
194 On the Sanatory and

 

ing, or at its minimum, for the two weeks
about the new and full. It is remarkable
that the point of greatest depression during
the year—viz., 28°67, was about twelve
hours after the new moon on the 8th of
November, and that of the greatest and
extraordinary elevation of 30°89, on the 7th
of February, at the time of the last quarter.
The variation from this coincidence seemed
to be owing to an evident perturbation of
the atmosphere. These observations were
confirmed by observations made for ten
years in the Royal Society’s apartments.
Mr. Howard supposes, therefore, that the
joint attractions of the sun and moon at the
new moon, and the attraction of the moon
predominating over the sun’s weaker attrac-
tion at the full, tend to depress the barometer

by taking off the gravity of the atmosphere,
Physiological Influence of Light. 195

 

as they produce a high tide in the waters by
taking off from their gravity; and again,
that the attraction of the moon being dimi-
nished by that of the sun at her quarters,
this diminution tends to make a high baro-
meter, together with a low tide, by per-
mitting each fluid to press with additional
gravity on the earth. It is demonstrated
a priori on the principles of the Newtonian
philosophy, that the air ought to have its
tides as well as the ocean, though in a degree
as much less perceptible as its gravity.* If
this observation were strictly true, and the
tides of the atmosphere were to those of the
sea as the specific gravity of air is to that of
water, the aérial tides must be extremely
small, for the weight of air is very trifling

compared to that of water. But it is known

 

* « Encyclopedia Britannica.”

0 2
196 On the Sanatory and

 

that the height of the tides of the sea bears
some proportion to the extent of the sea,
uninterrupted by land, and to its depth. On
both these accounts we should expect that
the atmosphere would be more influenced
by the moon’s attraction than the sea, for
it is vastly deeper and more extensive
than the sea, and entirely unconfined.
Signor Tolado found that a greater eleva-
tion of the barometer takes place at the
quarters than at the syzygies; it is less
when the moon is in the northern signs than
when in the southern. The mean diurnal
height, which corresponds to the Tropic of
Cancer, is less by a quarter of a line than
that which corresponds to the Tropic of
Capricorn. It is one-sixth of a line less at
the moon’s perigee than at her apogee, and

one-tenth of a line less at the syzygies than
Physiological Influence of Light. 197

 

at the quarters ; and there are vacillations in
the mercury when the new or full moon
corresponds to the apogean or perigean
points. He found, also, that the perigee,
the new and full moon, and the northern
lunistice are favourable to bad weather ;
whilst the apogee, the quadratures, and the
southern lunistice are more favourable to
good weather.

Pére Cotte, from observations of thirty-
five years, found that the barometer had a
tendency to descend at every new and full
moon, and to ascend at the quarterly periods.
He likewise found that the perigee and
northern declination depressed the barometer,
whilst the apogee and southern declination
had the oppssite effect.* Mr. L. Howard

 

* Orton, on “ Epidemic Cholera,” p. 222; and “ Lec-
tures on Meteorology,” by G. Luke Howard.
198 On the Sanatory and

 

has satisfactorily established, that the moon’s
position, operating by the common effects
of the attraction of gravitation, influences
alike the course of the variable winds, the
daily variations of the temperature, and the
rain of any year; but not in every year
alike, there being a constant periodical varia-

tion of the variation itself.*

 

* M. Kraszewski, of Romanow (as quoted by Andrew
Steinmetz in his work on .“ Sunshine and Showers”), has
decided, from a long series of observations:—“ 1. ‘That
63 times in roo the weather changes to bad when the
moon crosses our equator. 2. When the moon’s declina-
tion is north, bad weather occurs more frequently than
when it is south. 3. When the moon is in its perigee, and
at the equator, bad weather occurs 67 times in 100; when
in its apogee, but still at the equator, there is bad weather
63 times in 100; and 4. Generally the moon near the
equator determines bad weather in the same proportion.”
Physiological Influence of Light. 199

 

PART III,

 

ON THE ALLEGED INFLUENCE OF THE
MOON ON THE INSANE.

 

Tue recognised phrase, /unatic, is based on |
the hypothesis that the moon exercises a
decided effect upon the insane, and modifies —
various forms of morbid intellect which do
not amount to actual insanity: hence origi- /
nated the well known legal term, “ lucid

interval.”* It was supposed that during

 

* Lunatic, according to ancient legal dicta, is one whose i
imagination is influenced by the moon and has lucid in-
tervals: “ Lunaticus, qui gaudet lucidis intervallis.”

Sir W. Blackstone defines a person who is zon compos |
mentis to be one “who has had understanding, but by
200 On the Sanatory and

 

paroxysms of mental derangement, the pa-
tient was liable to: periods of lucidity or
mental repose, caused by the various phases:
of the moon. Acting on this assumption,
human life was often made contingent
upon a satisfactory solution of the ques-
tion, was or was there not a lucid interval
when a particular crime was committed?
The transmission also of property to a
vast amount often depended on the reply
to a similar interrogatory relating to a
period when a certain testamentary dispo-
sition was made. A lucid interval legally
implies a clear and distinct freedom of the —

mind from all delusions; in other words,

 

disease, grief, or other accident, has lost the use of his
reason; but that a lunatic is indeed properly one who
hath lucid intervals, sometimes enjoying his senses, and -
sometimes not, and that frequently depending upon the
change of the moon.” — Commentaries.”
Physiological Influence of Light. 201

 

such an intelligent repose and restoration of
the intellectual powers as to enable the
person mentally disordered to discriminate
accurately between right and wrong ; thus
constituting him morally and legally respon-
sible for his conduct, guoad any criminal act
of which he may have been guilty, or render-
ing him competent to exercise a sound
memory, judgment, and reflection relating
to any testamentary act he has, during a
questionable condition of mind, been called
upon to execute.

Into the judicial view of this important
and vexed question it would be foreign to

my purpose to enter.* I therefore propose

 

* The rule of law upon this subject is, that all acts
done during a lucid interval are to be considered done by
a person perfectly capable of contracting, managing, and
disposing of his affairs. This has most frequently been a
question in wills; and the Ecclesiastical Courts, which
ae

ote,

202 On the Sanatory and

 

confining my remarks to the main point at

issue, VizZ., is it satisfactorily established that

 

first promulgated the rule, adopted it from the Roman
law, “ Furiosi autem si per id tempus fecerint testamentum
quo furor eorum intermissus est, jure testatum esse widentur.”
—(Justin. Inst. lib. 11, tit. 12, s. 1).

A lucid interval consists not in a mere cessation of the
violent symptoms of a disorder; neither is it a cooler
moment, an abatement of pain or violence, relaxation from
a higher state of torture, or the relief of a mind from ex-
cessive oppression.

But an interval is that in which the mind, having thrown
off the disease, has recovered its general habit. The party
must be capable of forming a sound judgment of what he
is doing ; and his state of mind should be such, that any
indifferent person would think him able to manage his own
affairs.

M. D’Aguesseau, when pleading before the Parliament
of Paris, observed —“ That to constitute a lucid interval,

' there must not be a superficial tranquillity or shadow of

' repose; but on the contrary, a profound tranquillity, a

real repose ; there must be, not a mere ray of reason, which
only makes its absence more apparent when it is gone, not
a flash of lightning, which pierces through the darkness
only to render it more gloomy and dismal, not a glimmer-
Physiological Influence of Light. 203

 

the moon has any perceptible effect upon
the insane?

I should be giving but an imperfect
sketch of the literature of this subject if I
were not to refer to the fact that the poets,
as well as philosophers and medical writers
of ancient and modern times, have not failed
to countenance by the authority of their
genius the popular belief in the influence

of the moon not only on the bodily health,

 

ing which unites the night to the day ; but a perfect light,
a lively and continued lustre, a full and entire day, inter-
posed. between the two separate nights, of the fury which
precedes and follows it; and, to use another image, it is not
a deceitful and faithless stillness, which follows or forebodes
a storm, but a sure, steadfast tranquillity for a time, a real
calm, a perfect serenity; in fine, without looking for so
many metaphors to represent. our idea, it must not be a
mere diminution, a remission of the complaint, but a kind
of temporary cure, an intermission so clearly marked, as in
every respect to resemble the restoration of health.”
204. On the Sanatory and

 

but on the passions, and especially on the
mind when in a state of disorder. Most of
our great dramatic and epic poets have
embodied in their immortal creations this
idea. The works of Shakspeare, Spenser,
Beaumont and Fletcher, Ben Jonson, Mil-
ton, Byron, and Shelley are replete with
passages of exquisite beauty in relation to
this subject. Our own immortal bard,
whose marvellous apprehension and_pro-
found knowledge of the mind, intuitive
insight into the subtle workings of the
human heart and passions, and intimate
acquaintance with nearly every branch
of knowledge, department of science, art,
and philosophy, placed him like a bright
and brilliant constellation on a giddy emi-
nence, far above the rest of mankind,

has pointedly alluded to the moral and
Physiological Influence of Light. 205

 

mental influence of the moon on the heart
and intellect. In the ‘Twelfth Night,”

Viola apostrophizes Olivia as a

“ Most radiant, exquisite, and unmatchable beauty.”

“T heard you were saucy at my gates,” replies Olivia,
“ and allowed your approach, rather to wonder at you than
to hear you. If you be not mad, begone; if you have reason,
be brief; ’tzs not that time of the moon with me, to make

one in so skipping a dialogue.”

Again, in the play of ‘“ Antony and Cleo-
patra,” Enobarbus, after entering Czsar’s
camp, thus appeals to the moon :—

“ Be witness to me, O thou blessed moon |

When men revolted shall upon record
Bear hateful memory, poor Enobarbus did

1?

Before thy face repent

After which, he adds, addressing the
moon, previously to expressing his deep

contrition for his revolt against Antony—
2.06 On the Sanatory and

 

“O sovereign mistress of true melancholy,
The poisonous damp of night dispunge upon me;
That life, a very rebel to my will,

<a

May hang no longer on me.”

In “ Othello,” after the death of Desde-
mona, when a enters the chamber to
announce the foul murder of Roderigo by
the hand of Cassio, >the Moor, crushed to
the earth by an accumulation of horrible
misfortunes, exclaims in the agony of his
soul, and in the bitterness of wild despair—

“It is the very error of the moon,

She comes more near the earth than she was wont,

And makes men mad.”

In “King Richard the Third,” the
Queen, after rushing whilst in a state of
profound distraction, into the presence of
the Duchess of York to announce the death

of the King, passionately exclaims —
Physiological Influence of Light. 207

 

“ Give me no help in lamentation,
I am not barren to bring forth laments ;
All springs reduce their currents to mine eyes,
That I, being govern’d by the wat’ry moon,
May send forth plenteous tears to drown the world !”

Milton frequently alludes, in ‘* Paradise
Lost,” to the morbid effect of the moon. ;

He speaks-of

“ Demoniac frenzy, moping melancholy,

And moon-struck madness.”

In Ben Jonson’s “ Alchemist,” Tribula-

tion says—
“ But how long time,
Sir, must the saints expect ?”

To which Subtle responds—

“ Let me see,
How’s the moon now? Eight, nine, ten days hence
She will be silver potate ; then three days
Before to citronize,—some fifteen days.”*

Apart altogether from the astrological

 

* Act ili. scene 1.
i

208 On the Sanatory and

 

ideas prevalent in former times as to the
specific influence of the moon on the in-
sane, it is not difficult to understand why

this notion should have found favour among

learned, scientific, and experienced men.

It must be admitted that there is much of

the phenomena of insanity yet mysterious
and inexplicable. I refer particularly to

the remarkable periodicity that in many

cases accompanies the progress of this

disease. It is commonly supposed to be
difficult physiologically and pathologi-
cally to explain why such distinct periods
of apparent recovery should take place
during paroxysms of acute insanity. Cases
occur in which a patient is outrageously in-
sane one day, and to ordinary observers
sane the next; furiously mad one week,

calm and composed the next; mischievously
Physiological Influence of Light. 209

 

deranged in the mind for about a month or
six weeks, and then for an equal duration
in a sane state of intellect. Not only
are these lucid intervals or remissions often
noticed during the existence of the mental
malady but the character of the affection also
undergoes singular changes and modifications.
A patient recently under my care was sad
and depressed for one or two days, and
then for a similar period was in an exalted
and happy state of mental disorder.

Pinel knew a patient who became insane
regularly every year. This illness lasted
for three months, and terminated favou-
rably towards the middle of the summer.
Another patient was annually subject to
paroxysms of maniacal furor for a period of
fifteen days, but was in the perfect pos-
session of his reason for the remaining

P
210 On the Sanatory and

 

eleven months and a half. In another
case this physician noticed the attack of
insanity to come on every third day, being
in this respect analogous to the periodicity
observed in tertian intermittent fevers. _
In cases of acute melancholia, associated
with a suicidal feeling, the attacks often
_come on periodically. For a week or ten
“days the desire to commit suicide will pre-
vail, and then the insane craving for self-
destruction will suddenly vanish. A patient
may be strongly bent on suicide in the
morning and have no inclination to destroy
himself later in the day.
{Drunken madness or dipsomania, as it is
termed, in some cases comes on periodically,
Bruhl-Cramer cites an instance in which vio-
Jent paroxysms of intemperance occurred re-

gularly every four weeks at the new moon.
Physiological Influence of Light. 211

 

Most, another authority, confirms this fact.
In Henke’s Zeitschrift fiir Staatsarznei-
kunde, a case is related of monthly periodical
attacks of drunkenness, each attack occu-
pying eight days. The patient was ill in
this irregular way for seven years. Friedreich
says this periodicity is peculiarly characteristic
of attacks of dipsomania. In some cases
the paroxysms come on with great regu-
larity once in two, three, and four weeks,
In other instances several months intervene
between the attacks. Occasionally the pa-
tient is known to have seizures of dipso-
mania regularly every second, third, and
fourth year. Guislain mentions the case of
a woman whose temperate lucid intervals
extended over a period of four years. At
the end of this time the drunken madness re-
turned, lasting some time with great violence.

P 2
212 On the Sanatory and

 

Esquirol, Pinel, Falret, Cerise, Brierre de
Boismont, Baillarger, Foville, Calmeil, and
other celebrated French authorities, cite simi-
lar illustrations of the remarkable periodicity
so often associated with mental disorders.

Without giving the details of cases that
have come under my own personal observa-
tion, I may in general terms state that I
have frequently observed the phenomenon
referred to among insane patients. In this
respect, insanity in no way differs from
the periodicity which is so characteristic of
many forms of general disease; such as inter-
mittent fevers, gout, tic doloureux, cephalal-
gia, neuralgia, epilepsy, and other affections
in which the nervous system is implicated.

Is the periodicity alluded to as often
accompanying some types of insanity ex-

plicable apart from. the hypothesis of lunar
Physiological Influence of Light. 213

 

influences? I think there can be but one
opinion on this subject. The remarkable
remissions that occur during attacks of men-
tal derangement depend upon a variety of
causes, such as the removal, by appro-
priate treatment, of temporary congestion
of the brain, and irregularity of the cerebral
circulation; or the lucid moments may be the
effect of paying strict attention to dietetic
regimen, condition of the digestive organs,
bowels, liver, skin, and kidneys, or be the
result of carefully isolating the patient for
a time from all mental worry and excitement.

Pinel is of opinion that the periodicity
occasionally associated with insanity is more
dependent upon an undue indulgence of the
angry passions, intemperance in drinking,
inanition; or mental agitation caused by

a remembrance of the original exciting
I

t

1d On the Sanatory and

 

cause of the malady, than by direct lunar

influences. From a general examination’

Pinel made during the second year of the

republic, of the patients confined in the»

Bicétre, he found only fifty-two who were

subject to paroxysms of insanity at irregular

periods, and only six whose attacks were

characterized by a regular intermission.

In considering this subject, it is not my
intention to quote the somewhat fabulous
cases alleged to be illustrative of the moon’s
influence on the mind, recorded by ancient
and modern writers on astrology. Before,
however, referring to the opinions of the
great Roman authority in medicine, I think
the following facts, when viewed in relation
to the subject under discussion, worthy of
notice: Aristotle records the case of an

innkeeper at Tarentum who, although able
Physiological Influence of Light. 215

 

to attend to his business during the day,
became insane soon after the setting of
the sun! Bouillon cites the case of a
woman who lost the use of her senses at
sunset, but who recovered them at day-
break! Sauvage refers to a woman who
became maniacal whenever the sun was at its
zenith! An ineffectual attempt was made
to cure her of the malady by various strata-
gems, such as keeping her in a dark room
and deceiving her as to the hour.

In the chapter treating of Insanity, en-.
titled “ De tribus insanie generibus,” Celsus |
makes no special allusion to the influence of :
the moon on the insane. In the fourth
chapter of his first book, commencing “ De
suibus caput infirmum est,” he says ‘Cui
caput infirmum est, is, si bene concoxerit,

leniter perfricare id mane manibus suis debet ;
216 On the Sanatory and

 

nunquam id, si fieri potest, veste velare; ad
cutem tondere: utileque luna.” He then
adds the following advice, by which it is
clear that he viewed with grave suspicion
the injury likely to arise from an injudicious
exposure to the influence of the moon, es-
pecially ‘*defore her conjunction with the
sun.” “Utileque lunam vitare, maximeque
ante ipsum lune solisque concursum ; sed nus-
quam post cibum.”

Do the words “caput infirmum” mean
insanity in the right and generally received
acceptation of the term, or do they imply
a mere weakness of intellect so often ob-
served after attacks of ordinary fever, and
seen to follow other bodily diseases? The
latter construction appears to be the one
most generally adopted.

The late Dr. Haslam considered it more
Physiological Influence of Light. 217

 

than probable that the origin of the idea of
the moon exercising an influence on the
insane may be thus traced and explained :
The phases of the moon, and particular
female indispositions, are alleged to cor-
respond. The terms used to designate
them, have reference to the time when
both are completed. Insanity and epilepsy
are often connected with these conditions,
and suffer an exacerbation at the time when
they occur or ought to take place. If, there-
fore, the ailment referred to in an insane
person should be coincident with the full of
the moon, and the mind should ¢hez be more
violently disturbed, the recurrence of the
same state may be naturally expected at the
next full moon. Such has been the preva- (

5 at : i
lence of this opinion, that when patients were |

brought in former times to Bethlehem Hos- ,
i
218 On the Sanatory and

 

pital, especially from the country, their friends
have generally stated them to be worse at
some particular change of the moon, and of
the necessity they were under, at those times,
of having recourse to severe coercion. Some
of these patients, after recovering, have stated
that the overseer or master of the work-
house himself has frequently been so much
under the dominion of this planet (keeping
steadily in mind the old maxim, “ venienti
occurrite morbo”), that, without waiting for
any display of increased turbulence on the
part of the lunatics, he has barbarously
bound, chained, flogged, and deprived them
of food, according as he discovered the
moon’s age by the almanack!

To ascertain how far this opinion was
founded on fact, Dr. Haslam kept, during

more than two years, an exact register of
Physiological Influence of Light. 219

 

the numerous cases under his care, but with-
out finding, in any instance, that the aberra-
tions of the human intellect were influenced
by the phases of the moon.

As insane persons, especially those in a
furious state, are but little disposed to sleep,
even under the most favourable circum-
stances, they will be still less so when |
the moon shines brightly into their apart-.
ments.*

Dr. J. B. Woodward, late superintendent |
of the State Hospital, at Worcester, Massa-
chusetts, at the suggestion of one of the
most scientific men in New England, com- |
menced a table of observations on the in- |

fluence of this planet upon the paroxysms |

i

and deaths of the insane, and, after much |

 

* Haslam’s “ Observations on Madness and Melan-
choly,” pp. 214—217- London: 1809.
2.20 On the Sanatory and

 

time devoted to the subject, says :—‘* These
facts and coincidences we leave for the
present, with the single remark, that no
theory seems to be supported by them,
which has existed either among the ignorant
or wise men who have been believers in the
influence of the moon upon the insane.”

The report from which the preceding
passage is quoted then adds :—

‘“* Many patients are certainly more exci-
table and restless in pleasant moonlight nights
than in dark and gloomy weather ; but this
would seem to be occasioned by the real or
imaginary sight of objects in or without
the building, such as men, trees, animals,
&c., or the motion, perhaps, of the passing
clouds. An opinion, however, that has
existed for so long a period, which has spread

so extensively, and which, in this country,
Physiological Influence of Light. 221

 

is familiar as ‘ household words,’ deserves to
be carefully examined ; for it is important to
disprove error as well as to establish truth.

“< Weak and timid females are sometimes
alarmed and much agitated during the con-
tinuance of lightning and thunder ; but as
a general thing, we have not observed the
insane to be much disturbed on such occa-
sions.”

In the preceding passages I have endea-
voured accurately to record the opinions of
various accredited medical authorities adverse
to the theory of the moon’s influence upon the
insane.

“‘Ogni medaglio ha il suo reverso,” says
the well-known Italian proverb. So it is
with the vexed question under consideration.
I therefore proceed to an analytical examina-

tion of the conclusions which men of great
222 On the Sanatory and

 

experience, of undoubted eminence and
veracity have arrived at in favour of an
opposite hypothesis.

In the foremost rank among those who
| advocate the lunar theory, the illustrious
Frenchman, Pinel, justly occupies a
proud, elevated, and conspicuous position.
| The scientific world bows. with profound
“respect and reverence to every opinion to

which his masterly intellect gives expression.
This eminent physician thus addresses him-
‘self to the subject: ‘It is curious to trace
the effects of sol-lunar influence upon the
return and progress of maniacal paroxysms.
| They generally begin immediately after the
summer solstice, are continued with more
or less violence during the heat of summer,
and commonly terminate towards the de-

cline of autumn. This duration is limited
Physiological Influence of Light. 223

 

within the space of three, four, or five months,
according to deficiency of individual sen-
sibility, and according as the season may
happen to be earlier, later, or unsettled as
toits temperature. Maniacs of all descrip-
tions are subject to a kind of effervescence
or tumultuous agitation upon the approach of
stormy or very warm weather. They then
walk with a firm but precipitate step; they
declaim without order or connexion; their
anger is roused by trivial or imaginary
causes, and they express their feelings by
clamorous and intemperate vociferation.*
We must not extend this law of solar

influence beyond its natural boundary, nor

 

* In the year 1807, Mr. Thornton, then one of the .
apothecaries of Bethlehem Hospital, paid particular attention .
to the influence of the morning light upon all the patients
that were at the time confined in the asylum. Hecame to the
conclusion that many of them became noisy as soon as the
2.24. On the Sanatory and

 

conclude that the return of maniacal parox-
ysms is invariably dependent upon the at- -
mosphere. I have seen cases in which the
paroxysms return upon the approach of
winter, i.e. when the cold weather of De-
cember and January set in; and this re-
mission and exacerbation corresponded with
changes of the temperature of the atmo-
sphere from mildness to severe cold.”

The preceding quotation from Pinel’s
treatise on insanity is entitled to profound
respect. His sphere of observation was
great, his experience large, his veracity
unimpeachable, and what he saw he truth-

fully recorded. I think, therefore, we are

 

day began to break, and that, with the exception of two
or three recent cases, they all became silent and quiet
after night. During the eclipse of the sun on the 16th
of June, 1806, there was a sudden and total silence in
all the cells of the hospital!
Physiological Influence of Light. 225

 

bound, even in opposition to our own
judgment, to bow with great deference to
the conclusion at which this distinguished
physician arrived with regard to the in-
fluence of the moon on the insane.

Daquin, another eminent physician, }
directed his attention to this subject.
He occupied a high professional position
in France, and was universally respected |
for the zeal with which he cultivated
science, and the faithful accuracy displayed
in recording the results of his experience.
He was a close observer of nature, a man
of truth, and of highly.cultivated under-
standing.

In 1791 he published an able work on
insanity. In this he enters at length into

a discussion of this vexed question. With-

out quoting in detail the remarks of

Q
226 On the Sanatory and

 

Daquin, I shall content myself with gene-
ralizing the data. brought forward in sup-
port of the opinion he has formed with
reference to the influence of the moon
upon the mind when in a state of aber-
ration. He says :—

“It is a-well-established fact that in-
sanity is a disease of the mind upon which
the moon exercises an unquestionable in-
fluence. The new moons and the last
quarters of the moon are the lunar phases
which influence the insane most frequently
and painfully.

‘The first quarters and the full moons
are the phases which I have observed to
have the least influence in inducing relapses
of insanity ; the insane at these periods being
less insane, and quieter, and they reasoned

almost as if they were not ill at all.
Physiological Influence of Light. 2297

 

“© Those who are still susceptible of being
cured, as well as those who have been
cured, are precisely those upon whom the
two most powerful lunar phases have had
the greatest influence during the whole
of their illness.

“Those who are acutely maniacal are
much more susceptible to the influence of
the lunar phases than others.

“© T have also observed a difference be-
tween the influence exerted by this planet
on madness characterized by excessive joy,
and that by sorrow and melancholy.

‘Tt is proved that this influence is much
more marked in parts of the countries
bordering on the sea than in those at
a distance from it.”*

Amidst this conflict of testimony, what

 

* Daquin, “ Philosophie de la Folie,” rst edition, 1791.

Q 4
2.28 On the Sanatory and

 

\ conclusions can legitimately be drawn? Are
“we to consider the theory of lunar in-
fluence as a myth and an idle fable, or as a
well-established fact based upon accurate
and scientific data? It is impossible alto-
gether to ignore the evidence of such men
as Pinel, Daquin, Guislain, and others, and
yet the experience of modern psychological
physicians is to a great degree opposed to

the deductions of these eminent men.* Is

 

* Guislain has recorded the history of an insane patient
on whom the influence of the moon was observed. He
became maniacal every twenty-eight days. This dis-
;tinguished physician says, “ We have among our female
‘ patients a maniac sixty years of age. Her attacks of
‘acute insanity are periodical; the return of the disease
corresponding with the return of the full moon”—[Legons
Orales sur les Phrénopathies, Gand, 1852.]

Ina work entitled, “De PElectricité du Corps Humain,”
by Mons. Abbé Bertholon, the case of a lunatic is
recorded whose periodical accessions of acute mania oc-
curred invariably at the full of the moon.
Physiological Influence of Light. 229

 

it not probable that there is some degree
of truth on both sides of the question; in
other words, that the alleged changes ob-
served among the insane at certain phases
of the moon may arise, not from the direct,
but the indirect influence of this planet?
It is well known that certain important and
easily recognisable meteorological pheno-
mena result from the varied positions of
the moon ; that the rarity of the air, the
electric conditions of the atmosphere, its
degree of heat, dryness, moisture, and
amount of wind prevailing, are all, more
or less, modified by the state of the
moon. In the generality of bodily diseases
what obvious changes are observed to
accompany the meteorological conditions
referred to? Surely those suffering from

diseases of the brain and nervous system
2.30 On the Sanatory and

 

affecting the mind cannot, with any show
of reason, be considered as exempt from the
operation of agencies that are universally
admitted to seriously affect patients afflicted
with other maladies? That the insane do
appear to a degree unusually agitated at the
full of the moon, particularly if its bright
light is permitted uninterruptedly to enter
the room where they sleep, there cannot be
adoubt.* This phenomenon may, I think,
be accounted for apart altogether from the
hypothesis of there being anything specific
in the composition of the lunar ray.

In certain forms of insanity, particularly

those characterized by illusions. of the

 

* An intelligent lady, who occupied for about five years
the position of matron in my establishment for insane
ladies, has remarked, that she invariably observed a great
agitation among the patients when the moon was at its
full. This must be accepted guantum valeat.
Physiological Influence of Light. 231

 

senses or hallucinations of the mind, how
materially affected the patients are by the
kind and degree of light admitted into their
chambers. If exposed to a great degree
of natural, or even artificial light, the hallu-
cinations often become painfully intensified.
Sleeplessness often thus arises, and dormant
morbid visual and aural conditions pre-
viously in a latent state, become actively de-
veloped. Patients afflicted with distressing
delusions often imagine that everything they
see hasassumed the form of aterrible spectral
image. The presence of light emanating
from the moon, when at its full greatly tends
in these cases toaggravate the lunatic’s mental
sufferings. It is occasionally most desirable
to exclude light altogether from bedrooms
occupied by the insane, in order to tranquil-

lize them and cause sleep. In other instances
232 On the Sanatory and

 

the patient’s condition of mental excitement
becomes aggravated by being kept for a
length of time in darkness. It is therefore
often necessary, with the view of dissipating
a false creation which has seized hold of
his disordered imagination, to admit light
freely into the chamber. This has been
known immediately to compose the patient,
by convincing him of the morbid and illu-
sory character of his mental impression, and

inducing him to exclaim,— ‘

«“ There is no such thing !
It. is [my disordered brain]* which informs
Thus to mine eyes.”

 

* I hope I shall not expose myself to critical censure
for substituting the words “ disordered brain” for “bloody
business.”

+ Shakspeare has with exquisite poetic beauty and
wonderful psychological truth delineated, in the passage
from which the preceding lines are taken, the sudden
transition of the mind from apparent insanity (assuming
the form of an illusion of the senses) to that of health. -
Physiological Influence of Light. 233

 

If I were to confine the concluding re-
marks to the result of my own observations
on this subject, I fear I should be able to
add but little to what others have written
in relation to it. I freely admit that, placing
but little faith in what has been recorded or
said on the subject, I have not kept any
systematic register as to the effect of dif-
ferent phases of the moon on the insane.

It has been observed by some officials
connected with lunatic asylums, that occa-
sionally, from causes unknown to them,
many of the patients have simultaneously
exhibited a state of unnatural agitation.
This condition of the inmates has occurred
several times during the year, and at
irregular intervals; but the state of the
moon at the time was not made a matter of

observation. It is difficult to assign any
234 On the Sanatory and

 

cause for the alleged phenomenon, and it
would not be entitled to a moment’s con-
sideration if the commotion and excitement
that are said to take place were confined to a
few of the patients; but as many of the
insane inmates (several of them occupying
separate rooms) were noticed. to be thus
affected, at the same day and hour, the fact

becomes one worthy of record.*

 

* There can be no doubt that bright red, and yellow.
rays stimulate and in some cases irritate the brain and
mind. Deep blue is said to depress or exhaust the vital
force. Some animals are excited when brought in contact
with scarlet colour. This is observed at the bull-fights
that take place in different parts of Spain. Green, violet,
and in fact all the neutral tints, soothe the nervous system
and allay mental irritation. Those who have the care of
the insane, or medical treatment of patients suffering from
great brain irritability, should bear these facts in remem-_
brance.
Physiological Influence of Light. 235

 

PART IV.

 

HYGIENE OF LIGHT.

 

Havinc in the introductory part of this
work, referred in general terms to the
sanatory influence of light, I return to the |
subject in order to point out more specifically |
the deleterious effect of its absence on the
bodily health. I have previously alluded
to the important changes that take place in
the constitution of the blood in consequence
of the cutaneous vessels on the surface of
the body not being freely exposed to the
oxygenating and life-generating influence of
the sun. |
It is a well-established fact that, as the.
236 On the Sanatory and

 

effect of isolation from the stimulus of light,
the fibrine, albumen, and red blood-cells
become diminished in quantity, and the
serum, or watery portion of the vital fluid,
augmented in volume, thus inducing a
disease known to physicians and patho-
logists by the name of /ewkemia, an affection
in which white instead of red blood-cells are
developed.* This exclusion from the sun
produces the sickly, flabby, pale, anemic
condition of the face, or exsanguined ghost-
like forms so often seen among those not
freely exposed to air and light. The
absence of these essential elements of health
deteriorates by materially altering the phy-
sical composition of the blood, thus seriously

prostrating the vital strength, enfeebling

 

* Virchow’s “ Cellular Pathology,” 1860.
Physiological Influence of Light. 237

 

the nervous energy, and ultimately inducing
organic changes in the structure of the
heart, brain, and muscular tissue.* Do not‘
these facts suggest the great importance, |
particularly in a northern climate like that
of England, where the bright beams of the
sun so seldom shine, of so constructing our

habitations, both with regard to the number

of windows and position of the buildings, as

 

'
:

* “Where light is not permitted to enter the physician |

will have to go,” is the translation of a well-known Italian : '

proverb. Inthe eloquent words of Sir David Brewster, :
“ Light is the very life-blood of nature, without which
everything material would fade and perish ; the fountain of
all our knowledge of the external universe ; and the his-
toriographer of the visible creation, recording and trans-
mitting to future ages all that is beautiful and sublime in
organic and inorganic nature, and stamping on perennial
tablets the hallowed scenes of domestic life, the ever-varying
phases of social intercourse and the more exciting scenes of
bloodshed and war, which Christians still struggle to
reconcile with the obligations of their faith.”
238 On the Sanatory and

 

to admit within their walls a sufficient
degree of air and light; and are we not
bound to impress upon the legislature the
necessity of enacting some stringent pro-
tecting measures, with the view of pre-
venting low damp cellars and rooms being
crowded together, into which air and light
vainly struggle to penetrate, and where
so many thousands of the poorer classes
in our large towns are compelled to dwell,
to the utter sacrifice of every comfort
worth living for, and positive ruin to the
‘health of both body and mind ?* In several

 

* The following is an extract from a recently published
report of the health commissioners of the State of New
York :—“ In no other city in the civilized world is there to
be found half a million of people so unhealthily housed, as a
class, as the tenant house population of New York. In less
than sixteen thousand houses, on lots that average scarcely
twenty-five by one hundred feet, there dwell nearly five
hundred thousand people; and in the cellars of those
Physiological Influence of Light. 239

 

English manufacturing cities, until within

the last few years, the great proportion |

 

houses nearly sixteen thousand more poor, whose poverty
and ignorance allow no election of better homes.”

The Rev. Isaac Taylor, incumbent of St. Matthias,
Bethnal Green, thus describes in a printed circular the
terrible state of the poor of his parish. The statement |
is copied from the Pall Mall Gazette of February r2.
« The mortality among young children is something fright -
ful. I do not know anything more terrible than the state-
ments which one continually hears. It is a common thing:
for a mother to say that she has buried six or eight, and .
reared one or two. This mortality among the children is
chiefly owing to the deadly overcrowding, and to insuffi-
ciency of food and clothing. Last summer we found a
family of eight children living with their father and mother
in a room some ten feet square, and almost in a state of
starvation. All the children had the small-pox out upon
them; they had no medical care or nursing; the only
medicament that had been used was a little oil rubbed
over their faces; this the father said he had heard was
good for the small-pox. ‘The man was engaged meanwhile |
in the delicate work of making white chenille, to be sold
in the fashionable West-end shops. Hardly a family in i
the parish possesses more than a single room, in which all j |
the members live, work and sleep.”
240 On the Sanatory and

 

of the working classes lived either under-
ground, in courts, or in narrow streets, and.
houses almost destitute of windows, ap-
parently constructed for the specific purpose
of admitting the minimum portion of air
and the smallest possible degree of light
consistent with the preservation of health
and the maintenance of life.* It was com-

puted not many years ago that in Liverpool

 

* Sir David Brewster, in his opening address delivered in
November of last year at the Royal Society of Edinburgh, has
suggested an easy and valuable remedy for these frightful
evils. His remarks afford a valuable illustration of the
facility with which the great truths of science may be
practically applied in promoting the comfort and health of
the human race :—“ If, in a very narrow street or lane, we

look out of a window with the eye in the same plane as
the outer face of the wall in which the window is placed,
we shall see the whole of the sky by which the apartment
can be illuminated. 1 we now withdraw the eye inwards, -
we shall gradually lose sight of the sky till it wholly dis-
appears, which may take place when the eye is only 6 in. or
8 in. from its first position. In such a case the apartment
Physiological Influence of Light. 241

 

between 30,000 and 40,000 people lived in

cellars. Asa consequence of this state of |

things, the health of the working classes
became seriously affected. Legislative
measures were adopted for the purpose of
declaring such habitations illegal, and those
living in them were ejected by the strong
arm of the law. In 1849, 4,700 cellars

were cleared of 20,000 inhabitants.

 

is illuminated only by the light reflected from the opposite
wall, or the sides of the stones which form the window ;
because, if the glass of the window is 6 in. or 8 in. within
the wall, as it generally is, not a ray of light can fall upon
it. If we now remove our window, and substitute another
in which all the panes of glass are roughly ground on the
outside, and flush with the outer wall, the light from the
whole of the visible sky, and from the remotest part of the
opposite wall, will be introduced into the apartment, re-
flected from the innumerable faces or facets which the

rough grinding of the glass has produced. The whole

window will appear as if the sky were beyond it, and from
every point of this luminous surface light will radiate into

all parts of the room.”
R

‘=: &
442 On the Sanatory and

 

Rightly recognising the life-giving and
health-sustaining influence of light, the
‘Towns Improvement Clauses Act of
Scotland” enacted that no cellars less than
seven feet high, without a window, and of
which more than two-thirds are below the
level of the street, should be inhabited,
Acting upon the authority of this statute,
the corporation of the city of Edinburgh
has considerably improved the physical con-
dition of the working classes of that town
by peremptorily closing 3,000 dreary, sun-
less dens, in which the poor people were in
the habit of residing.

How eloquently and truthfully has Sir
David Brewster illustrated this section of:
my subject. He says:—If the light of
day contributes to the development of the

human form, and lends its aid to art and
Physiological Influence of Light. 243

 

nature in the cure of disease, it becomes
a personal and national duty to construct
our dwelling-houses, schools, workshops,
factories, churches, villages, towns, and
cities upon such principles and in such
styles of architecture as will allow the
life-giving element to have the fullest and
the freest entrance, and to chase from every
crypt, cell, and corner the elements of
uncleanness and corruption which have a
vested interest in darkness.

** Although I have not visited the prisons .
and lazarettos of foreign countries, to de-_
scribe the dungeons and caverns in which |
the victims of despotism and crime are :
perishing without light and air, yet we have|
seen enough in our own country—in private
houses, in the most magnificent of our
castles, and in the most gorgeous of our

R 2
244, On the Sanatory and

 

palaces—to establish the fact that there is
hardly a house in town or country without
dark apartments which it is in the power of
science to illuminate. In most of the
principal cities of Europe, and in many of
‘the finest towns of Italy, where external
“nature wears her brightest attire, there are
streets and lanes in which the houses on one
‘side are so near those on the other, that
‘hundreds of thousands of human beings
are neither supplied with light nor air, and
‘carry on their trades in almost total dark-
ness. Providence—more beneficent than
man—has provided the means of lighting
up to a certain extent the workman’s home,
by the expanding power of the pupil of his
eye, and by an increasing sensibility of his
retina; but the very exercise of such

powers is painful, and every attempt to see
Physiological Influence of Light. 245

 

when seeing is an effort, or to read and
work with a straining eye and an erring
hand, is injurious to the organ of vision,
and sooner or later must impair its powers.
Thus, deprived of the light of day, thou-
sands are compelled to carry on their trades
principally by artificial light—by the con-
sumption of tallow, oil, or gas—-thus in-
haling from morning till midnight the
offensive odours and polluted effluvia which
are more or less the products of artificial
illumination.

“Tt is in. vain to expect that such evils,
shortening and rendering miserable the life
of man, can be removed by legislation or
arbitrary power. In various great cities
attempts are making to replace their densely
congregated streets and dwellings by struc-

tures at once ornamental and salutary ; and
246 On the Sanatory and

 

Europe is now admiring that great renova-
tion in a neighbouring metropolis, by which
hundreds of streets and thousands of
dwellings, once the seat of poverty and
crime, are replaced by architectural com-
binations the most beautiful, and by hotels
and palaces which vie with the finest edifices
of Greek or of Roman art.”*

Fourcault cites a striking illustration of
the sad effects of the absence of light on the
health of young children. On one occasion
his attention was attracted to the mutilated
condition of several large mulberry trees,
the branches of which, before their decay,
effectually shaded the schoolroom in which
a number of orphan girls affected with

chronic diseases were educated. On asking

 

* “ An Address delivered at the Opening of the Session
for 1866-7, at the Royal Society; Edinburgh.”
Physiological Influence of Light. 247

 

the reason for the mutilation, he was in-
formed that the shade of the trees visibly
increased the severity of the scorbutic affec-
tions that prevailed among the children,
and that a very favourable change had taken
place in the condition of the girls since their
exposure to the unimpeded light of the sun.*

Utterly regardless of the principles just
enunciated, how often do we see parents,
who cannot for a moment be considered in-
different as to the present and future health
of their offspring, adopting the most in-

genious means of effectually excluding light

from the bodies of young infants and
children! No course can be more detri-
mental to their health than the one just

referred to, because the value of an im-

 

* “ Causes Générales des Maladies Chroniques,” p. 42.
248 On the Sanatory and

 

portant vital element is systematically ignored
at a period of life when it is of the highest
importance it should be brought to bear upon
the purification of the blood, and consequent
healthy development of organic structures.
Children, even at an early age, should
not be excluded, particularly during the
warm periods of the vear, from the genial
and cheering influence of the sun. The
sanatory effect of light can be easily
made available even during the winter
months (in rooms properly ventilated and
heated) with little or no danger. Great
benefit to the health would accrue by giving

| children what the ancients termed solaria,
or ‘‘solar-air baths ;” that is, permitting
| them to lie naked upon the bed or floor,

free from the incumbrance of swaddling-

clothes, so that their bodies may be
Physiological Influence of Light. 249

 

thoroughly brought under the influence,
for some period of the day, of good air and
bright sunlight. The children of Sea
as well as of negroes, who are often allowed, |
as soon as they can walk alone to run about |
in the open air (i puris naturalibus) freely
exposed to the influence of light, have
finely-developed muscular structures, and

generally enjoy robust health.*

 

* “ Passing round St. Paul’s Churchyard the other day,
our ear caught a low confused sound, which seemed to '
issue from behind a grille under the gloomy portico of St.
Paul’s School. Attracted by so unusual a sound, and ;
blinded for a moment by passing from the sunlight under \
the portico, we at length made out that the sound was }
that of boys’ voices in play. After a little time, when our
eyes had become accustomed to the darkness, and permitted
us to penetrate the dreary recess, we perceived that some
score of boys were actually at play within its unhappy
shade. Such a profound sanatory error on the part of the
authorities of the school as to shut up their youth in a

cage, without light or air, and there bid them play, struck
2.50 On the Sanatory and

 

| No amount of artificial, polarized, or
| reflected light will compensate for the
want of the direct action of the sun.

Humboldt, in the account he has pub-
lished of his voyage to the equinoctial re-

gions, says, when speaking of the Chaymas,

 

us with some astonishment. Boys at their games are like
young birds singing on the bough; half their joy is a
result of the influence of the sunny air. We are told,
indeed, that only a very short time is spent in this gloomy
retreat ; but surely it is hard that the hour of recreation,
when academic art should give way to nature, should be
selected for this depressing process as at present carried
on. What would Dean Colet have said to it? When
the St. Martin’s national school, leading out of Endell-
street, was built some years ago, we noticed with plea-,
sure that a playground was built at the top of the school,
where light and air were plentiful, conditions essential in
a playground where children use violent exercise; but
this example we are sorry to see has no effect upon
the Mercers’ Company. The necessity of light for
young children is not half appreciated. Many of the
afflictions of children, and nearly all the cadaverous looks
Physiological Influence of Light. 251

 

“both men and women (whose bodies are
constantly inured to the effect of light) are
very muscular, and possess fleshy and
rounded forms. It is needless to add that

I have not seen among these people a

single case of natural deformity. I can say —

 

of those brought up in great cities, are ascribable to
this deficiency of light and air. When we see the glass-
rooms of the photographers in every street high up on
the topmost story, we grudge them their application to a
mere personal vanity. Why should not our nurseries be
constructed in the same manner? If mothers knew the
value of light to the skin in childhood, especially to
children of a scrofulous tendency, we should have plenty

of these glass-house nurseries, where children may run

about in a proper temperature, free of much of that ‘

clothing which at present seals up the skin—that great
supplementary lung—to sunlight and oxygen. Glass-
house nurseries lifted up to the topmost story would save
many a weakly child that now perishes for want of those
necessaries of infant life.”

I copy the preceding sensible remarks, so strictly in
conformity with my own views, from the Pal! Mall
Gazette. They are from the pen of Dr. Andrew Wynter.
252 - On the Sanatory and

 

the same of many thousands of Caribs,
Maysias, Mexicans, and Peruvian Indians,
whom I observed during five years. De-
formities and deviations from healthy phy-
sical development are exceedingly rare in
certain races of men, especially those which
have the skin strongly coloured, who
wander about naked under the brilliant
light of the tropical regions. These have
muscular fleshy bodies, rounded contours,
and present none of those deformities so
frequently observed among the inhabitants
of other climates.”

Dr. Bryson, in his memorandum to the
Lords Commissioners of the Admiralty re-
Jating to the health of seamen, has pointed
out the great difference between the ap-
» pearance of sailors employed in the dark

bread-room and holds of ships, and those
Physiological Influence of Light. 253

 

who are freely exposed to air and sunlight
on deck, or in open boats, at all hours of
the day: he therefore considers it of im-
portance to “‘ascertain whether exclusion
from the solar rays be not, to a greater
extent than is generally believed, one reason
why these men, who have in consequence
acquired a pale waxy look from confine-
ment below, are more susceptible to disease,
and less capable of sustaining its shocks,
than are those whose blood is enriched and
strengthened by the free exposure to light,
heat, and air which their different avoca-
tions ensure. The force of these remarks,
however, will be best understood by those
who have had opportunities of witnessing
the rapid change which takes place in the
human constitution by exposure for only

a short time to the direct rays of a tropical
254 On the Sanatory and

 

sun, Why, in a state of perfect repose,
the blood should acquire a brighter tinge
and an increased force of circulation are
inquiries the value of which the observant
physiologist will not fail justly to appreciate;
neither will he fail, as often as opportunities
occur, to follow up these phenomena, should
they terminate in disease, or unhappily
produce death.”*

| The inestimable value of light as an
lelement in the preservation of health
and treatment of disease, should be fully
‘appreciated in the construction of all streets
“and buildings, particularly those intended
“as habitations for the poor, or public

hospitals for the treatment of disease. It

{

 

* “ Manual of Scientific Inquiry,” published by autho-
rity of the Lords Commissioners of the Admiralty, edited
by Sir John F, W. Herschel, Bart. London, 1849.
Physiological Influence of Light. 255

 

is a well-ascertained fact that many mala-
dies are more susceptible of amelioration, if
not of cure, provided the light of the sun
is freely admitted into the rooms or wards
where invalids are domiciled.*

Apart altogether from the cheerfulness
and mental serenity (important auxiliaries in
the eradication of disease!) which the bright
rays of the sun invariably engender, light

has a thermic influence upon the mind and

 

* Some years ago, when visiting the great hospital of ,
St. John, at Brussels, 1 was much impressed with the ;
most judicious hygienic arrangements made in the con- ;
struction of that building for the health and comfort of
the invalids) On the roof of the hospital an elegant:
garden is laid out with great taste, and planted with |
shrubs, small trees, and a grass lawn, interspersed with |
pretty and sweet-smelling flowers. It is, in fact, a Parc |
de Monceau in miniature. In this quiet rural retreat, |
patients, particularly the convalescents, are permitted at
certain hours of the day to promenade, indulging in the
luxury of good air and bright sunlight.
256 On the Sanatory and

 

body when prostrated by serious ailments, |
and certainly acts beneficially by chemically
purifying the blood of the patient, as well
as the atmosphere of the apartment he
occupies.

There are, of course, active conditions
of bodily and mental disease, such as small-
pox, inflammatory conditions of the skin
and brain, acute mania, ophthalmia, &c.,
which require to be carefully excluded from
the stimulus of light. I have elsewhere
addressed myself to this subject.

Florence Nightingale has entered so fully
‘into this subject, that I offer no apology
' for quoting in extenso her extremely judi-
cious remarks relative to the importance of
| keeping prominently in view, in the archi-
tectural construction of public hospitals, the

sanatory value of light to the sick. She says:
Physiological Influence of Light. 257

 

“Second only to fresh air, however, I /
should be inclined to rank light in im- |

portance for the sick. Direct sunlight, not _
only daylight, is necessary for speedy reco- |
very; except, perhaps, in certain ophthalmic |
and a small number of other cases. In-
stances could be given, almost endless,
where, in dark wards or in wards with a
northern aspect, even when thoroughly
warmed, or in wards with borrowed light,
even when thoroughly ventilated, the sick
could not by any means be made speedily
to recover.

«Among kindred effects of light I
may mention, from experience, as quite
perceptible in promoting recovery, the
being able to see out of a window, in.
stead of looking against a dead wall; the
bright colours of flowers; the being able

Ss
258 On the Sanatory and

 

to read in bed by the light of a window
close to the bed-head, It is generally said
that the effect is upon the mind. Perhaps
so; but it is no less so upon the body on
that account.

“* All hospital buildings in this climate
should be erected so that as great a surface
as possible should receive direct sunlight—
a rule which has been observed in several
of our best hospitals, but, I am sorry to say,
passed over in some of those most recently
constructed. Window-blinds can always
moderate the light of a light ward; but the
gloom ofa dark ward is irremediable.

‘¢ The axis of a ward should be, as nearly
as possible, north and south; the windows
on both sides, so that the sun shall shine
in (from the time he rises till the time

he sets) at one side or the other. There
Physiological Influence of Light. 259

 

should be a window to at least every two
beds, as is the case now in our best hospi-
tals. Some foreign hospitals, in countries
where the light is far more intense than in
England, give one window to every bed.
The window-space should be one-third of
the wall-space. ‘The windows should reach
from two or three feet of the floor to one
foot of the ceiling. The escape of heat
may be diminished by plate or double glass.
But while we can generate warmth, we can-
not generate daylight, or the purifying and
curative effect of the sun’s rays.”*

Many facts are on record, illustrative of
the decidedly beneficial effect of the free
admission of light into public buildings set

apart as receptacles for cases of disease.

 

* “Notes on Hospitals,” by Florence Nightingale.
Third edition, pp. 19, 20. London: Longmans, 1863.

52
2.60 On the Sanatory and

 

| Sir James Wylie, of the Imperial Russian
Service, pointed out to an English physi-
cian one of the barracks at St. Petersburg,
in which three cases of disease occurred on
the dark or shaded side of the establish-
ment for one on the other, though the
apartments on both of these sides com-
" municated freely with each other, and the
discipline, diet, and treatment were in every
respect the same.*
' A very remarkable instance of recovery
_ from disease has been related by the late
| Baron Dupuytren, the eminent French sur-
; geon, and cited in a work on Light published
| by the Society for Promoting Christian
Knowledge. A lady residing in Paris, had

suffered for many years from an enormous

 

* “Onthe Theory and Practice of Ventilation,” by
R. B. Reid, M.D. 1855.
Physiological Influence of Light. 261

 

complication of diseases, which had baffled
the skill of all her medical advisers, and
her state appeared almost hopeless. As a
last resource, the opinion of Dupuytren
was requested upon her case, and he, un-
able to offer any direct medical treatment
essentially differing from all that had been
previously tried in vain, suggested that she
should be taken out of the dark room in
which she lived, and away from the dismal |
street, to a brighter part of the city, and
that she should expose herself as much as
possible to the daylight. The result was
quickly manifest in her rapid improvement,
and this continued until her recovery was
complete. An equally singular instance
has been related by Southey, in the case

of his own parent.*

 

* “Tn chlorosis, scrofula, phthisis, and, in general, every
26.2 On the Sanatory and

 

“Tn the years of cholera, when this
frightful disease nearly decimated the popu-
lation of some of the principal cities in the
world, it was invariably found that the
deaths were more numerous in narrow
streets and northern exposures, where the

salutary beams of light and actinism had

 

disease characterized by deficiency of vital power, light
should not be debarred to the patient. In convalescence
from almost all diseases it acts, unless too intense or too
long continued, as a most healthful stimulant, both to
the nervous and physical systems. ‘The evil effects of
keeping such invalids in obscurity are frequently very de-
cidedly shown, and cannot be too carefully guarded against
by the physician. ‘The delirium and weakness, which are
by no means seldom met with in convalescents kept in
darkness, disappear like magic when the rays of the sun
are allowed to enter the chamber. I think I have no-
ticed that wounds heal with greater rapidity when the
light is allowed to reach them than when they are kept
continually covered.” (Dr. Hammond’s “Treatise on
Hygiene.”)
Physiological Influence of Light. 263

 

seldom shed their beneficial influence. This
resistless epidemic found an easy prey among
a people whose physical organization had
not been matured under those benign in-
fluences of solar radiation which shed health
and happiness over our fertile plains, our
open valleys, and those mountain sides
and elevated plateaus where man breathes
in the brighter regions of the atmosphere.”*

I have spoken previously of the inesti-
mable benefits which accompany a liberal
exposure of the body to the action of the
solar beam. I cannot pass unnoticed the
positive mischief that often arises from a
prolonged action of intense light on the
visual organs, as well as the injury often

caused by a sudden transition from a

 

* Sir D. Brewster.
264 On the Sanatory and

 

moderate to a great or glaring degree of
the sun’s influence.*
Soldiers are said often to suffer in their

eyes from the reflection of the rays of the

_ sun from white sand or snow. Lévy records
. that in 1819 the Swiss troops in garrison at

| Lyons had many of their number affected

 

* A sudden transition from perfect darkness (particularly
if of considerable duration) to an intense degree of light
produces a most painful and dazzling sensation in the
retina, accompanied by a feeling of acute pain in the eye-
balls, as well as of the head. These symptoms are often

| associated with temporary blindness. The tyrant Dionysius,
' being aware of these facts, inflicted on some of his unhappy
‘i prisoners the severe punishment of compelling them to pass
; rapidly from great darkness to the full blaze of the sun in
: recently white-washed rooms!

An officer of high rank in the army of Charles I. went

to Madrid, with the view of executing an important mission

| for the king, but failing in his generous attempt to do his
Majesty a signal service, he was arrested by the Spanish

\Government, and ordered to be incarcerated in a dark and
‘dismal dungeon, into which light never entered except
when a small hole at the top of the cell was opened
Physiological Influence of Light. 265

 

with hemeralopia, accompanied with ner-
vous symptoms, such as nausea and vomit-
ing, caused, it is supposed, by drilling under
a hot sun.*

This disorder. of the vision is said to
arise from two very different causes: 1st,
an exposure to a stronger light than the eye
has been accustomed to; 2ndly, a deficiency
of the black pigment which lines the choroid
membrane. This affection of the eye is

commonly observed among those who live

 

by the jailer for the purpose of giving the prisoner
food. This unfortunate Royalist was confined in the
dungeon for several months: he was then set at liberty.
Such, however, was the effect of the darkness upon his
nervous system, eyes, and optic nerve, that he was
compelled to live for some time afterwards in a dark
room, in order gradually to accustom himself to the
stimulus of light.

* A form of intermittent blindness, characterized by
the patient being able to see only in broad daylight, and
becoming totally blind at sunset.
266 On the Sanatory and

 

in dark caverns, mines, dungeons, or prisons.
It is frequently seen among the peasants of
Italy, who are employed in agricultural pur-
suits, This is attributed to the peculiar
brightness of the Italian sky, remark-
able clearness of the atmosphere, and re-
laxingly warm condition of its tempera-
ture. The peasants of Italy are thus ex-
posed to the joint operation of almost every
cause that can produce habitual debility of
the iris and irritability of the retina. This
complaint is most frequent on return of
spring, or at the vernal equinox.
Ramazzini says that such is the degree of
. dimness of vision which this exposure to
"intense light induces, that the peasants lose
their way in the fields in the glare of noon,
but that on the approach of night they are
again able to see distinctly. In the treat-
Physiological Influence of Light. 267

 

ment of these cases it is found necessary to
keep the patients for some weeks in the
shade, or in comparative darkness, until the
eyes recover their healthy tone. This disease
of the eye is said to be endemic in some
parts of France, particularly in the neigh-
bourhood of Roche Guion, on the banks of
the Seine. So generally does it prevail
that we are told upon good authority, that
it affects one in twenty of the inhabitants in
one village, and in another, one in ten every
year. It shows itself in the spring, and
continues for three months, returning in a
slighter degree in the autumn. The soil of
this part of France consists of dazzling
chalk, and it is thought that the intensity of
the first reflected light after the dreariness of
the winter in all probability is the cause of

the malady.
268 On the Sanatory and

 

This is a common affection in Russia
‘during the summer months, when the eyes
are exposed almost without intermission to
the constant action of light, as the sun then
dips but little below the horizon, and there
is scarcely any interval of darkness. The
peasants who protract their hard labour in
the fields from a very early to a very late
hour, and at the same time exhaust and
weaken themselves by their daily fatigue,
are subject to this malady. Mr. Guthrie
has published an account of a detachment
of Russian soldiers, in which this disorder
suddenly manifested itself. They were
ordered to attack a Swedish post at the
moment the affection of the eyes developed
itself, and had nearly destroyed one another
by mistake, owing to their visual powers

being impaired. These soldiers had been
Physiological Influence of Light. 269

 

harassed by long marches, and exposed
night and day to the piercing glare of
an uninterrupted range of snowy moun-
tains.*

“© The only persons I have myself seen ,
affected with hemeralopia have been those
just returned from sea voyages—most com-
monly from the East or West Indies—and '
who have consequently been exposed to a
strong glare of sunlight. The affection is,
I believe, also met with among the inhabi-
tants of the inland parts of India, who
attribute it, just as our own sailors do,
to sleeping when exposed to the moon-

beams.

® « Mém. de la Société Royale de Méd., 1786.” “ Me-
moirs of the Medical Society of London,” by Mr. Guthrie.
“ The Study of Medicine,” by John Mason Good, M.D.,
F.R.S.
270 On the Sanatory and

 

‘* The real cause of hemeralopia appears
to be exhaustion of the nervous suscepti-
bility of the retina from over-excitement by
the sun’s rays, whereby the part is rendered
incapable of appreciating the milder rays of
twilight or moonlight.

‘ But this exposure to strong light is not
always the cause of the affection ; for I have
met with it among those who had never
quitted the temperate parts of the globe.
In most of the latter cases, however, the
complaint has shown itself after voyages
which had subjected the patients to exhaust-
ing labour, and exposure to severe weather,
when deprived of their proper supply of
fresh provisions and vegetables.

«I have commonly found that a few
weeks’ residence on shore, with a whole-

some mixed diet and the use of quinine,
Physiological Influence of Light. 271

 

has restored their vision to a_ healthy
state.”*

This disorder of the vision is generally |
associated with a scorbutic condition of the |
system. It prevailed to a considerable |
extent among the French and English
soldiers during the Crimean campaign. It
no doubt arose from their long-continued
exposure to an intense glare of light,
which their eyes had not been accustomed
to. An eminent American ophthalmic prac-
titioner, says, that a surgeon attached to the
garrison of Strasbourg, in France, has pro-
posed what he claims to be a speedy and effec-

tual mode of curing this malady. He con-

 

* “ A Guide to the Practical Study of Diseases of the
Eye,” by James Dixon, F.R.C.S. England, Surgeon to
the Royal London Ophthalmic Hospital, Moorfields
London, 1866.

+ Dr. Henry W. Williams,

|
|
'
272 On the Sanatory and

 

fines his patients in an entirely dark room for
a considerable number of hours, not allowing
light to enter even foran instant. The eyes
thus being left in complete repose, recover
their normal tone. Relapses, he asserts,
are quite rare, provided the seclusion has
been of sufficient duration. Soldiers suf-
fering from this ailment are advised to be
removed into the interior of the country
from seaboard stations, particularly if ex-
posed there to the glare from white sand.
Snow and ice blindness is a common affec-
tion among thosewho reside foraconsiderable
time in the Alpine or Arctic regions.*
Sheep are known to temporarily lose their

sight if permitted to wander over mountains

* Dr. Hammond knew a child who was rendered per-
manently blind by looking intently at a bright object
while she was having her photograph taken,
Physiological Influence of Light. 273

 

covered with snow ; but it returns a short
time after the snow and ice are melted.

The Greek soldiers, as related by}
Xenophon, suffered severely in their eyes
from the reflection of the intense light
of the sun as they crossed the mountains of
Armenia.

It is impossible, whilst considering this
matter, to leave altogether unnoticed the
hygienic treatment of the eyes, when mor-
bidly affected by artificial light.

Persons exposed for an undue length of
time to the glare of brilliantly-lighted rooms
often suffer from chronic ophthalmia and
other affections of the organ of vision.
Literary men, from the same cause, are
liable to attacks of musce volitantes and
amaurosis. ‘Tailors, sempstresses, shoe-
makers, jewellers, watchmakers, and, in

T
Paine de as

274 On the Sanatory and

 

fact, all who work by artificial light, are
subject to serious disorders of the eye.
Under these circumstances they often be-
come acutely sensitive to light.* — Ac-
cording to a distinguished oculist, light is
injurious to the eyes in proportion as the
red and yellow rays prevail. These produce
cerebral and visual excitement, followed

by debility of the retina.t He suggests

 

3

* Mr. Ernest Hart says that when great sensitiveness to
light exists tinted (plain) spectacles are indicated. He ob-
serves—“ The ordinary smoked glasses may be advan-
tageously substituted in such cases by those tinted of a
cobalt blue, which sufficiently exclude the irritating yellow
and red rays, without cutting off too much light, or pro-
ducing an unpleasant obscurity.” —“ On some of the Forms
of Disease of the Eye,” by Ernest Hart, Ophthalmic Sur-
geon to St. Mary’s Hospital, &c., p. 21. 1864.

+ It has been established by direct experiment that the
violet ray of the solar spectrum is actually capable of ren-
dering a needle magnetic which has never been touched by
the loadstone or by an artificial magnet (Steinmetz).
Physiological Influence of Light. 275

 

as a remedy for the injurious effects of
red and yellow colours that the light
should be surrounded by a shade, tinted
blue on its inner surface. The blue rays
reflected from it will produce a tolerably
pure and white light, by their union with
the reddish-yellow rays of the flame. To
effect the same purpose the lamp should be
enveloped by a glass chimney, tinged inside
with a very pale blue, or the light should be
made to pass through a fluid of the same
colour.*

In an early part of this work I have re-
ferred in general terms to the important
results obtained by Fraunhofer, Kirchhoff,
and Bunsen, with reference to the existence

of metallic lines (‘ Fraunhofer’s lines”)

 

* “ Practical Remarks on Near and Aged Sight,” by
W. White Cooper, Esq., F.R.C.S. England. 1847.

T 2
276 On the Sanatory and

 

observed in the sunlight by means of the
‘spectrum.* It has naturally been a matter
of discussion with medical men engaged in
sanatory investigations, whether the “vapour

of iron,” found to exist in conjunction with

 

\

* We can no longer consider light as merely consisting
‘ of infinitesimal particles, or as infinitesimal qaves ; we
may now conclude that it is »zetallic,.—that sunshine con-
; sists of a metallic ¢ shower,’ such as the Greek mythology
ascribed to Jupiter in one of his unions with mortals
| (strange coincidence of fact with emblematic fiction !) ;
but, instead of a shower of gold, according to the figment,
the beneficent sunshine bathes us with elementary iron,
sodium, magnesium, calcium, chromium, nickel, barium,
copper, zinc, and hydrogen! It is Jupiter, not Apollo,
that the ancient mythology should have identified with the
sun. Inthe idea of Zews (or the ‘Burner’) and the Zeuspater
(Father Jove) of the Latins, we might translate all the
amours of the Father of the Gods into physical facts con-
nected with the ‘arch-chemic sun, as Dante’calls him,
and. recognise the idea that all animals are children of the
sun.”—“ Sunshine and Showers,” by Andrew Steinmetz,
Esq., of the Middle Temple, Barrister-at-Law. London,
1867.
Physiological Influence of Light. 277

 

other metals in the sun’s atmosphere, has any
hygienic effect upon the physical organism
as the result of the therapeutic action of iron
on the blood distributed so freely through
the minute capillary vessels ramifying on
the surface of the body? In the absence of
any hypothesis of a more satisfactory cha-
racter to account for the beneficial action of
light, it is reasonable to suppose that the
iron vapour detected in the sun’s beam may
have a physiological as well as a mechanical
effect upon the composition of the blood
by throwing into the general circulation,
through the vessels of the skin, a most
important vital constituent.*

In the present state of our knowledge it

is impossible to dogmatise on this subject.

 

* There does not appear to be anything improbable in
this hypothesis,when we consider that mercury may be made
278 On the Influence of Light.

 

The matter in review must still be considered
sub judice, and purely speculative, and until
further experiments are made it is wise to.
hold in reserve any theory that may have

been formed in relation to it.

 

to affect the system by subjecting the patient to its influ-
ence in the form of a vapour-bath, the mercury of course
being absorbed principally by the skin, although a portion
may pass into the lungs. That persons handling the soluble
salts of lead are often poisoned in consequence of the
metal passing through the integuments is a generally ad-
mitted fact.

Dr. Th. Clemens, of Frankfort-on-the- Maine (Deutsche
Klinik, 1865-6, Schmidt’s Jahrbiicher, 1866), has “ob-
served the immunity from cholera of coppersmiths. Hence
he recommends as a cholera disinfectant a spirit of chlorate
of copper, and advises the same preparation to be used
both internally and externally upon the skin as an actual
preservative.’—Half-yearly Abstract, 1866, p. 5.
I

Il.

Til.

Iv.

VI.

VII.

VIII.

IX.

XI.

XII.

279

APPENDIX.

THE BLESSINGS OF LIGHT: MILTON’S BLINDNESS.

SUGGESTIONS FOR THE REGULATION OF LIGHT
IN DARK ROOMS, ETC.

THEORIES OF LIGHT.

EFFECT OF LIGHT ON THE SKIN.
THE SUN.

NUTRITION OF PLANTS.
VITALITY OF SEEDS.

THE MOON.

ANIMALS INFLUENCED BY THE STATE OF THE
WEATHER.

ON THE DISTRIBUTION OF LIGHT BY ARTIFICIAL
MEANS.

ADVANTAGES OF LIGHT IN THE TREATMENT OF
THE SICK.

ON THE REGULATION OF THE QUANTITY OF
LIGHT ADMITTED INTO THE CHAMBERS OF
THE SICK.
Appendix. 283

 

THE BLESSINGS OF LIGHT: MILTON’S
BLINDNESS.

(Vide Preface.)

In the subjoined lines Milton alludes with touching
_ . : . o«
“pathos to his own sad deprivation of sight :—

“ Thus with the year
Seasons return, but not to me returns
Day, or the sweet approach of eve or morn,
Or sight of vernal bloom, or summer’s rose,
Or flocks, or herds, or human face divine;
But cloud instead, and ever-during dark
Surrounds me, from the cheerful ways of men
Cut off, and for the book of knowledge fair
Presented with an universal blank
Of Nature’s works, to me expunged and rased,
And knowledge at one entrance quite shut out.”

I append to the preceding affecting wail of dis-
tress a copy of a posthumous poem (having reference
to his blindness) said to have been written by
Milton. I have not been able to ascertain at what
period these lines were penned ; but, assuming them
to be genuine, I should suppose they were written
long subsequently to the verses previously quoted.
They are deeply interesting, as showing the state of
282 Appendix.

 

Milton’s feelings with regard to his infirmity at
different epochs of his life :—

I.

“JT am old and blind!
Men point at me as smitten by God’s frown ;
Afflicted and deserted of my mind—
Yet I am not cast down.

Il.

“Tam weak, yet strong ;
I murmur not that I no longer see—
Poor, old, and helpless, I the more belong,
FatHer Supreme! to THEE.

Ill.

“O merciful One!
When men are farthest, then Thou art most near;
When friends pass by, my weakness shun,
Tuy chariot I hear.

Iv.

“Tuy glorious Face
Is bending towards me, and its holy light
Shines in upon my lonely dwelling-place, .,
And there is no more night.
Appendix. 283

 

Vv.

“On my bended knee
I recognise Thy purpose clearly shown :
My vision Thou hast dimmed, that I may see
TuyseLr—Tuyse-r alone.

VI.

“I have naught to fear;
This darkness is the shadow of Tuy wing ;
Beneath it Iam almost sacred—here .,
Can come no evil thing.

Vil.

“QO! I seem to stand
Trembling where foot of mortal ne’er hath been,
Wrapped in the radiance of that sinless land,
Which eye hath never seen.

VIII.

“Tt is nothing now:
When heaven is op’ning on my sightless eyes,
Soft airs from Paradise refresh my brow,—
The earth in darkness lies.
284 Appendix.

 

Ix.

‘Visions come and go;
Shapes of resplendent beauty round me throng ;
From angel lips I seem to hear the flow
Of soft and holy song.

Xe

“In a purer clime
My being fills with rapture—waves of thought
Roll in upon my spirit—strains sublime
Break over me unsought.

XI.

“ Give me now my lyre!
I feel the stirrings of a gift divine ;
Within my bosom glows unearthly fire,
Lit by no skill of mine.”
Appendix. 285

 

SUGGESTIONS FOR THE REGULATION OF
LIGHT IN DARK ROOMS.

(®. 7.)

“In all great towns, where neither houses nor
palaces can be insulated, there are almost in every
edifice dark and gloomy crypts thirsting for light ;
and in the city of London there are places of busi-
ness where the light of day never enters, and where
the precious light which the sky sends down be-
tween chimney-tops is allowed to fall useless on the
ground. On visiting a friend whose duty confined
him to his desk during the official part of the day,
we found him with bleared eyes struggling against
the feeble light which the opposite wall threw into
his window. We counselled him to extend a blind
of fine white muslin on the outside of his window,
and flush with the wall. The experiment was soon
made. The light of the sky above was caught by
the fibres of the linen, and thrown straight upon his
writing-table, as if it had been reflected from an
equal surface of ground glass. We may mention
another case equally illustrative of our process. A
party visiting the mausoleum of a Scottish nobleman
wished to see the gilded receptacles of the dead
which occupied its interior, There was only one
286 Appendix.

 

small window through which the light entered, but
it did not fall upon the objects to be examined.
Upon stretching a muslin handkerchief from its four
corners, it threw such a quantity of light into the
crypt as to display fully its contents.”

Sir D. Brewster.

THEORIES OF LIGHT.
(P. 13.)

I have referred to the two theories that have pre-
vailed in the scientific world regarding the nature
and propagation of light —viz., the corpuscular
theory of the immortal Newton, and the undulatory
theory of Huygens, afterwards revived and fully
elaborated by Dr. Young. Sir Isaac Newton sup-
posed that light was composed of particles of ex-
cessive minuteness, which were projected from the
luminous body with a velocity equal to 193,000
miles in a second. The undulatory theory was
based upon the hypothesis, that light was trans-
mitted from its source by vibrations or undulations
of an ethereal fiuid of great elasticity in spherical
superficies in the form of waves, similar to the

transmission of sound.
Appendix. 287

 

The principles of the undulatory theory are thus
stated by Sir J. Herschel :—

1. That an excessively rare, subtle, and elastic
medium, or ether, fills all space, and pervades all
material bodies, occupying the intervals between
their molecules; and either by passing freely among
them, or by its extreme rarity, offering no resistance
to the motion of the earth, the planets, or comets
in their orbits, appreciable by the most delicate
astronomical observations, and having inertia, but
not gravity.

2. That the molecules of the ether are susceptible
of being set in motion by the agitation of the par-
ticles of ponderable matter; and that when any one
is thus set in motion it communicates a similar
motion to those adjacent to it, and thus the motion
is propagated farther and farther in all directions,
according to the same mechanical laws which regu-
late the propagation of undulations in other elastic
media, as air, water, or solids, according to their
respective constitutions.

3. That in the interior of refracting media the
ether exists in a state of less elasticity, compared
with its density, than 2m vacuo (i.e., in space empty
of all other matter) ; and that the more refractive
the medium, the less, relatively speaking, is the
elasticity of the ether in its interior.
288 Appendix.

 

4. That vibrations communicated to the ether in
free space are propagated through refractive media
by means of the ether in their interior, but with
a velocity corresponding to its inferior degree of
elasticity.

5. That when regular vibratory motions of a
proper kind are propagated through the ether, and,
passing through our eyes, reach and agitate the
nerves of our retina, they produce in us the sensa-
tion of light in a manner bearing a more or less
close analogy to that in which the vibrations of
the air affect our auditory nerves with that of
sound.

6. That as, in the doctrine of sound, the fre-
quency of the aérial pulses, or the number of
excursions to and fro, from the point of rest made
by each molecule of the air, determines the pitch,
or note; so, in the theory of light, the frequency
of the pulses, or number of impulses made on our
nerves in a given time by the ethereal molecules
next in contact with them, determines the colour
of the light ; and that as the absolute extent of the
motion to and fro of the particles of air determines
the loudness of the sound, so the amplitude or extent
of the excursions of the ethereal molecules from
their points of rest determines the brightness or
intensity of the light.—Dictionary of Science, Lite-
Appendix. 289

 

rature, and drt. By W. T. Brande, D.C.L.,
F.R.S. L. & E.

EFFECT OF LIGHT ON THE SKIN.
(P. 20.)

“ Amongst the carpenters I noticed one with a ;
remarkable staining of the skin, some portions of
his face and neck being intensely bronzed, while
other parts remained quite fair, giving the man a_
very unsightly mottled appearance. In plain terms,
he was enormously freckled, the stained skin being |
about the average colour of the faces of the artisan |
and labouring classes in the north of China. His
disfigurement, consequently, arose from the refusal
of the whole of the exposed portions of his body
equally to take on the bronzing process. I made
him show me his skin where habitually protected
from the sun, and it was as fair as an European’s,”’"—
Peking and the Pekingese. By D. F. Rennie, M.D.
London. 1865. :
290 Appendix,

 

THE SUN.
(P. 68.)

“ The sun
Had first his precept so to move, so shine,
As might affect the earth with cold and heat
Scarce tolerable, and from the north to call
Decrepit winter, from the south to bring
Solstitial summer’s heat. To the blank moon
Her office they prescribed ; to the winds they set
Their corners, when with bluster to confound
Sea, air, and shore; the thunder when to roll
With terror through the dark aerial ball. ,
Beast now with beast gave war, and fowl with fowl,
And fish with fish: to graze the herb all leaving,
Devoured each other, nor stood much in awe
Of man, but fled him, or with countenance grim
Glared on him passing.”"—Murton.

“The sun’s rays are the ultimate source of almost
every motion which takes place on the surface of the
earth. By its heat are produced all winds, and those
disturbances in the electric equilibrium of the atmo-
sphere which give rise to the phenomena of light-
ning; and probably, also, to those of terrestrial
magnetism and the aurora. By their vivifying
Appendix. 291

 

action vegetables are enabled to draw support from
inorganic matter, and become, in their turn, the
support of animals and of man, and the sources of
those great deposits of dynamical efficiency which
are laid up for human use in our coal strata. By
them the waters of the sea are made to circulate in
vapour through the air, and irrigate the land, pro-
ducing springs and rivers. By them are produced
all disturbances of the chemical equilibrium of the
elements of nature, which, by a series of composi-
tions and decompositions, give rise to new products,
and originate a transfer of materials. Even the
slow degradation of the solid constituents of the
surface, in which its chief geological changes con-
sist, is almost entirely due, on the one hand, to the
abrasion of wind and rain,and the alternation of
heat and frost ; on the other, to the continual beat-
ing of the sea waves, agitated by winds, the results
of solar radiation. ‘Tidal action (itself partly due
to the sun’s agency) exercises here a comparatively
slight influence. The effect of oceanic currents
(mainly originating in that influence), though slight
in abrasion, is powerful in diffusing and transporting
the matter abraded ; and when we consider the im-
mense transfer of matter so produced, the increase
of pressure over large spaces in the bed of the ocean,
and diminution over corresponding portions of the

U 2
292 Appendix.

 

land, we are not at a loss to perceive how the elastic
power of subterranean fires, thus repressed on the
one hand, and relieved on the other, may break
forth in points when the resistance is barely adequate
to their retention, and thus bring the phenomena of
even volcanic activity under the general law of solar
influence.

“The great mystery, however, is to conceive how
so enormous a conflagration (if such it be) can be
kept up. Every discovery in chemical science here
leaves us completely at a loss, or rather, seems to
remove farther the prospect of probable explana-
tion. If conjecture might be hazarded, we should
look rather to the known possibility of an indefinite
generation of heat by friction, or to its excitement
by the electric discharge, than to any actual com-
bustion of ponderable fuel, whether solid or gaseous,
for the origin of the solar radiation.” —Good Words.
Appendix. 293

 

NUTRITION OF PLANTS.
(P. 79.)

* Since the sun-light is composed of many dif- |

ferently coloured rays and different principles, it
becomes an interesting inquiry which of these is the
immediate agent in ministering to the nutrition of
plants. In 1843, by causing plants to effect the
decomposition of carbonic acid in the prismatic
spectrum, I found that the yellow is by far the
most effective, the relative powers of the various
colours being as follows :—1, yellow; 2, green;
3, orange; 4, red; 5, blue; 6, indigo; 7, violet.”
—Draper.

VITALITY OF SEEDS.
(P. 79+)

It has been a question with botanists how to
account for the longevity or vitality of seeds: I
refer particularly to wheat, which has been found
in Egyptian sarcophagi, proved to be many thousand
years old. These seeds, when put into the ground,
have fully germinated, and been most productive.
The persistent vitality of such seeds, according to

Rikers nat,
294 Appendix.

 

the best botanical authorities, depends upon three-
principal conditions, viz.: 1, uniformity of tem-
perature; 2, moderate dryness; and 3, the exclu-
sion of light. Seeds brought from India (says Dr.
Lindley) round by the Cape of Good Hope rarely
vegetate freely. This he says is owing to the
double exposure to the heat of the equator, and
the subsequent arrival of the seeds in cold Jati-
tudes. Seeds brought overland from India, and
not exposed to such fluctuations of temperature,
retain their active vital principle. Seeds will travel
with safety for many months if buried in clay
rammed hard in boxes. Seeds of the mango are
thus brought alive from the West Indies, as well
as the principal part of the araucania pines which
have been transported from Chili to England.

THE MOON.
(P. 89.)

The moon appears to have called forth the fire
and sublimity of poetic genius in all ages and in
all climes. Some of the most beautiful and touch-
ing sonnets that adorn the English language are
addressed to the moon. I cannot forbear to quote
Appendix. 295

 

an illustration from the pen of Charlotte Smith,
one of our most exquisite writers of sonnets, the
immortal Milton alone excepted :—

“Queen of the silver bow !—by thy pale beam,
Alone and pensive, I delight to stray,

And watch thy shadow trembling in the stream,
Or mark the floating clouds that cross thy way ;
And while I gaze, thy mild and placid light
Sheds a soft calm upon my troubled breast :
And oft I think—fair planet of the night—
That in thy orb the wretched may have rest ;
The sufferers of the earth, perhaps, may go—
Released by death—to thy benignant sphere ;
And the sad children of despair and woe
Forget in thee their cup of sorrow here.

Oh, that I soon may reach thy world serene!
Poor wearied pilgrim in this toiling scene!”

“In savage life, especially in high latitudes, the
moon is an ever-present power. When the Red
Indian speaks of moons as measures of time, he
speaks in the tone of affection and reverence for
the benign luminary that guides his steps through
the trackless forest. The Oriental bows to-the sun,
but the Red Indian nurtures his grand and impas-
sive nature in the mild beams of the moon. In
hunting and trapping, the moon is his ever-taithtul
2.96 Appendix.

 

ally, and he would as soon think of doubting its use:
as he would the use of his spear or his traps.

« But the use of the moon is not confined to Jig ht-
giving. As a mechanical power, the moon is of
much service. The sun is the grand source of
power on the face of the earth; but still some little
work is left for the moon. To her chiefly is as-
signed the task of raising the tides of the ocean.
The tides are of incalculable benefit to man. Ina
sanitary point of view, the moon may be regarded
as the great scavenger of our globe. Twice every
‘day she flushes, with sea-water in abundance, the
rivers on which our towns are situated, and keeps
them comparatively pure. Again, by her mechani-
cal power, she bears ships on the crest of the tidal
wave deep into the heart of the country, where the
centres of commerce are often found. Insignificant
streams are thus rendered navigable, and cities
brought into immediate connexion with the ocean—
the highway of commerce. By the convenience
afforded by the moon, London is at the same time
connected with the ocean, and in the heart of the
country, where it can be best protected from any
invasion. In an island of such limited extent as
Great Britain, the rivers must necessarily be small,
but the tidal wave compensates for the defect, and
gives us the advantages of river navigation. The
Appendix. 297

 

mechanical power of the tide is made available by
means of the tide-mill. The rise and fall of the
tide can be utilized as well as the fall of the river.
This source of power has not been very generally
turned to account, though there is no mechanical
difficulty in applying it.”,—Good Words.

ANIMALS INFLUENCED BY THE STATE
OF THE WEATHER.

(P. 229.)

Many of the diseases of animals are greatly in-
fluenced by states of the atmosphere. It is re-
marked that immediately before rain, and particu-
larly before great falls of snow in winter, dogs are
dull: their ears become inflamed, and they lie
drowsily by the fire the principal part of the day.
Swine are observed to be uneasy in windy weather,
and show symptoms of restlessness even before the
winds begin to blow by running about with a
peculiar tossing up of the head. Hence the popular
notion that pigs can foresee the wind.

——
298 Appendix.

 

ON THE DISTRIBUTION OF LIGHT BY
ARTIFICIAL MEANS.

(P. 237-)

With the object of distributing light, Sir David
Brewster suggests that “the opposite sides of the
street or lane should-be kept whitewashed with
lime, and for the same reason the ceilings and walls
of the apartments should be as white as possible,
and all the furniture of the lightest colours. Having
seen such effects produced by imperfect means, we
feel as if we had introduced our poor workman or
needle-woman from a dungeon into a summer-
house, where the aged can read their Bible, where
the inmates can see each other, and carry on their
work in facility and comfort.”

ADVANTAGES OF LIGHT IN THE TREAT-
MENT OF THE SICK.

(P. 255+)

“Who has not observed the purifying effect of
light, and especially of direct sunlight, upon the air
ofa room? Here is an observation within every-

body’s experience. Go iuto a room where the
Appendix. 299

 

shutters are always shut (in a sick-room or a bed-
room there should never be shutters shut), and
though the room be uninhabited, though the air
has never been polluted by the breathing of human
beings, you will observe a close, musty smell of
corfupt air—of air, ie., unpurified by the effect of
the sun’s rays. The mustiness of dark rooms and
corners, indeed, is proverbial. The cheerfulness of a
room, the usefulness of light in treating disease, is
all-important.

“Heavy, thick, dark window or bed - curtains
should, however, hardly ever be used for any kind
of sick in this country. A light white curtain at the
head of the bed is, in general, all that is necessary,
and a green blind to the window, to be drawn down
only when necessary.

“«Where there is sun there is thought.’ All
physiology goes to confirm this. Where is the
shady side of deep valleys, there is cretinism.
Where are cellars and the unsunned sides of narrow
streets, there is the degeneracy and weakliness of
the human race—mind and body equally degenerat-
ing. Put the pale withering plant and human
being into the sun, and, if not too far gone, cach
will recover health and spirit.

“Tt is a curious thing to observe how almost all
patients lie with their faces turned to the light, ex-
300 Appendix.

 

actly as plants always make their way towards the
light ; a patient will even complain that it gives
him pain ‘ lying on that side.’ ‘Then why do you
lie on that side?? He does not know; but we do.
It is because it is the side towards the window. A
fashionable physician has recently published in a
Government report that he always turns his patients’
faces from the light. Yes, but nature is stronger
than fashionable physicians, and depend upon it she
turns the faces back, and towards such light as she
can get. Walk through the wards of a hospital,
remember the bedsides of private patients you have
seen, and count how many sick you ever saw lying
with their faces towards the wall.”"—Notes on
Nursing. By Florence Nightingale.

 

ON THE REGULATION OF THE QUANTITY
OF LIGHT ADMITTED INTO THE CHAM.
BER OF THE SICK.

(P. 287-)

“The quantity of light admitted into the sick-
chamber is a matter of immense importance to its
suffering occupant. As light is an element of cheer-
fulness, it is on that account desirable that as much
Appendix. 301

 

should be admitted as the patient can bear without
inconvenience. The light should be soft and sub-
dued, not glaring; and care should be taken that
bright, lustrous objects, such as crystals and looking-
glasses, should be kept out of the patient’s view, and
that neither the flame of a lamp or candle, nor its
reflection in a mirror, be suffered to annoy him by
flashing across his field of vision.”—Ripce On
Health and Disease.

THE END
LONDON:
SAVILL AND EDWARDS, PRINTERS, CHANDOS-STREET,
COVENT GARDEN.
OW orks
OW THE

DISORDERS OF THE MIND, DISEASES OF THE BRAIN,
PSYCHOLOGICAL MEDICINE, AND
THE MEDICAL JURISPRUDENCE OF INSANITY,

By FORBES WINSLOW, M.D.

On the Incubation of Insanity.
(Pamphlet.)
The Health of Body and Mind.

(1 Vol., 8vo.)

III.
The Anatomy of Suicide.
(1 Vol., 8vo.)
“Ty.
Lettsomian Lectures on Insanity.
(1 Vol., 8vo.)

The Plea of Insanity in Criminal

Cases.
(1 Vol., 12mo.)
WORKS BY FORBES WINSLOW—continued.

 

ON THE
Obscure Diseases of the Brain, and
Disorders of the Mind.

(Third Edition. 1 Vol., 8vo.)

Quarterly Journal of Psychologicalz
Medicine and Mental. Pathology.
(8vo.)

(Seventeen Annual’ Volumes of this Work have been published.)

VIII.

On Uncontrollable Drunkenness;

CONSIDERED AS A FORM OF
Mental Disorder.

ETC. ETC.

(Pamphlet.)