The Significance of a Declining- Death Rate By Frederick L. Hoffman, LL. D. Statistician The Prudential Insurance Company of America Address delivered before the National Conference on Race Betterment Battle Creek, Mich., January, 1914 •:. fi> ^^ !.(■""■■- ■-, THE SIGNIFICANCE OF A DECLINING DEATH RATE Introduction The social and economic problems which arise out of a considerable decline in the general death rate, extending over a prolonged period of time, are much more serious and far-reaching than is generally assumed to be the case. In practically all civilized countries there is annually a considerable excess of births over deaths, the numerical excess being conditioned more generally by a low mortality than by a high fecundity. For illustration: A given country might have a birth rate of forty and a death rate of thirty, with a resulting annual natural increase of ten per one thousand, whereas another country might have a birth rate of only thirty but a death rate of fifteen, with a resulting natural increase of fifteen per one thousand. From an economic and social point of view a low birth rate and a low death rate would unquestionably be more ad- vantageous than the opposite condition, which involves much need- less waste of human energy and pecuniary expenditure. For reasons which require no discussion, every civilized country desires a normal increase in population, though a high degree of social and economic wellbeing is not at all inconsistent with even a stationary population condition, such as for some years past has prevailed in France. It has properly been observed that the term population embraces the most extensive subject of political economy, and most of the observations and conclusions which follow comprehend the problem of population increase throughout the world rather than the underlying elements of fecundity and mortality. On account of the world-wide migratory movements of modern populations, involving the transport of vast numbers from one region to another, it has been necessary to include in the present discus- sion some very general and rather approximate statistics of population increase, resulting from an annual excess of births over deaths, with, however, numerous and necessary illustrations for the several continents and countries in detail. The population problem is no longer merely a local one, but practically conditions the material, moral and political wellbeing of the inhabitants of the entire world, though, of course, to a variable degree. The Population Problem of Modern Times From the time when Malthus first visualized in popular language the menace of a rapidly increasing population on the assumption of a less rapidly increasing food supply, much speculation has been indulged in as regards the ultimate results of population growth on the strictly limited land area of the globe. Much of what goes by the name of Malthusianism stands for something never said by Malthus in his classi- cal "Principles of Population," just as much that stands for evolution or Darwinism was never given utterance or sanction by Darwin in his "Origin of Species," and the "Descent of Man." Pre-Malthusian doctrines of population are of historical rather than practical interest, largely because of the imperfect statistical basis upon which most of the earlier estimates of population growth were based by writers in many respects sound in their philosophical and economic theories. We have no modern contributions to the population problem which correspond to the elaborate and well-reasoned inquiries of William Godwin on "The Power of Increase in the Numbers of Mankind," published in 1820; of Michael Thomas Sadler on "The Law of Population," published in 1830; and Archibald Alison's treatise on "The Principles of Population, and Their Connection with Human Happiness," published in 1840. Sir William Petty, in his famous essays on Mankind and Political Arithme- tic (1682-87), assumed that a given population would double itself by natural increase during a period of twelve hundred years. This estimate was well sustained by the experience of a period when plague, pestilence, famine and wars frequently resulted in a stationary condition of popula- tion, or even in a substantial actual diminution. Petty, in one of his twelve considerations of the conditions which affect the increase in the numbers of mankind, properly included methods of preventing "the mischief of plagues and contagions," which, although only a theoretical assumption at that early period, foreshadowed the enormous sanitary progress of modern times and the realized ideals in the administrative control of the public health. There is nothing more instructive in this respect than the sanitary evolution of the City of London, so admirably set forth in a work by Henry Jephson and the still larger and more useful work by Creighton on "The History of Epidemics in Britain," which is a monumental contribution to the progress in medical science and all that is summed up in the term civilization, which is fundamentally con- ditioned by the highest attainable average duration of human life. The world of to-day is not free from pestilence and plague, or famine and war, but, comparing the present with the past, it is an absolutely safe assumption that the waste of human life was never relatively as small in the world's history as is the case at the present time. There are still vast areas of the world, such, for illustration, as India, where fevers, cholera and plague cause an enormous annual mortality, best illustrated by the fact that during so recent and short a period as 1896-1912, there should have been over eight million deaths from plague in India, to say nothing of other sections of Asia similarly afflicted to a greater or less extent. The relative significance of preventable diseases in their relation to the general death rate is best illustrated in the case of the Presidency of Bengal, where, during the year 1911, out of a total mortality of 32.69 per one thousand, 20.60 represented deaths from fevers;* 2.37, deaths from cholera; and 1.44, deaths from plague. These three groups of causes com- bined, therefore, accounted for a death rate of 24.41 per one thousand, or 74.7 per cent, of the mortality from all causes. Considered by local areas in which cholera was particularly virulent, it appears that there were towns in which the death rate attained to the almost inconceivable proportion of 97.35 per one thousand (Gaya), of which 11.87 was caused by cholera, 35.61 by fevers, and 19.99 by plague. Such conditions are extremely rare in modern civilized communities, although as illustrated in the cholera epidemic of the city of Hamburg, f the menace of serious local outbreaks is by no means a remote possibility. The sanitary security of modern countries depends largely upon the highest attainable degree of efficiency in the control of so-called international diseases, and in this respect no country in the world has a better public health service than the United States. Population Density The effect of excessive death rates on population increase is so obvious as not to require extended consideration. India in 1911 had a birth rate of 38.6 per one thousand and a death rate of 32. But for the prevalence of epidemic and largely preventable diseases the natural increase in population would have been much greater than was actually the case. Some observations regarding the world's population, its continental distribution and relative density, are, therefore, pertinent to the general discussion of the significance of a declining death rate, particularly with reference to population growth. The number of inhabitants of the globe is conservatively estimated at 1,750,000,000, and assuming that the land area of the earth is about 52,000,000 square *In explanation of the term "fevers" as used in the vital statistics of India, the following explanation is quoted from the First Report on Malaria in Bengal, by Major A. B. Fry, M. D.; Calcutta, 1912: "Everything not cholera, smallpox or something equally obvious is put down as fever. In effect we have to accept the fact that fever deaths as reported comprise all deaths not due to these obvious diseases. Marasmic and premature infants, infants dying of tetanus neonatorum, improper feeding and bowel diseases, nearly all deaths from respiratory diseases, including both phthisis and pneumonia, measles, enteric fever, etc., etc., are included under the fever heading. Even cholera and plague are often returned as fever, especially at the com- mencement of an epidemic." fDuring the cholera year of 1892 the general death rate of Hamburg was 39.5 per one thousand population. There were 13,948 cases of cholera, of which 5,805, or 41.6 per cent., were fatal. The cholera death rate for the year was 12.7 per one thousand, equivalent to 32.2 per cent, of the death rate from all causes » miles, the resulting density is approximately thirty-four persons per square mile. For the European continent the density is one hundred and twenty-one persons; for Asia, fifty -seven; for Africa, twelve; for North America, fifteen; for South America, seven; and for Australia, including New Zealand, two and three-tenths. The facts, in detail, are given in the table following: Approximate Density of the World's Population Estimated by Continents for the Year 1911 C"*-* Scales Ration JSfiS! Europe 3,833,567 463,997,000 121.0 Asia 16,997,639 962,233,000 56.6 Africa 11,760,689 135,987,000 11.6 North America 8,631,657 127,993,000 14.8 South America 7,184,021 51,193,000 7.1 Australasia 3,317,762 7,572,000 2.3 *Total land area 51,725,335 1,748,975,000 33.8 *Does not include the practically uninhabited polar regions. It seems unnecessary on this occasion to discuss in detail the relative density of population of different countries or political subdivisions, but it may be said that for the more important countries the range in density is approximately from an extreme of 659 persons per square mile in Belgium, 475 in the Netherlands, 374 in the United Kingdom and 343 in Japan to a minimum of 31 for the United States, 13 for the Union of South Africa, 6 for Brazil, 2 for Canada and 1.6 for the Commonwealth of Australia. Contrarily to the common assumptionas regards the "teeming millions" of the Far East, it may be pointed out in this connection that the density of population for China is approximately 100 persons per square mile, and for British India, 178. The term "density of population" is, of course, only relative, in that the same has no reference to the actual distribution of population over a given area.* A country may have a relatively high density, due to a vast aggregation of population in a few cities, and another may have a relatively low but more widely dispersed density of far greater economic importance. The latter condition, for illustration, prevails in India, which in part explains the extreme difficulties of effective methods of local sanitary control. It would also be an error to forecast, on the basis of the foregoing estimates of . *For an interesting discussion of what is assumed to be a new law of population concentration, see an article in Petermanns Geogr. Mitteilungen, February, 1913, entitled "Das Gesetz der Bevolkerungs Konzentration," by Dr. Felix Auerbach. density, the probable future limits of population growth. Belgium, with the highest relative density, is one of the most prosperous countries of Europe, but is dependent almost entirely for its food supply upon other countries, in which as yet the density of population is very considerably below the average for at least the European continent. There can be no question of doubt but that vast opportunities still exist for a very sub- stantial increase in the number of the earth's inhabitants, but consider- ing the attained degree of density in certain countries and the uncon- ditional dependence of population aggregates for their food supply upon more sparsely settled areas, assumptions regarding the future possibil- ities of population increase are likely to be exaggerated since the pres- sure upon the limited available means of subsistence must become more generally operative than is the case at the present time. Growth of the World's Population The growth of the world's population is naturally determined by the excess of births over deaths and the resulting gradual accumulation of the new-born over the diminishing remnants of previous generations. A persistently and rapidly declining death rate, therefore, unless offset by an equal decline in the birth rate, must, in course of time, result in a proportionately more rapid increase in population than has been ob- served to have taken place during historic periods of time. The ulti- mate effect of such an accumulation of births over deaths must be in geometrical rather than in arithmetical proportions, in the same manner as in pecuniary calculations the results of compound interest are con- siderably in excess of the yield of money invested at simple interest only. Accepting for the present purpose the estimate of the world's popu- lation for 1900 of 1,607,000,000, as given by Sundberg, and my own estimate for 1911 of 1,749,000,000, there has been an annual increase during the intervening period of 12,883,000, or at the rate of 7.7 per one thousand. For purposes of comparison, it may be stated that during the same period of time the population of the continental United States has increased from 75,994,575 in 1900 to 93,927,342 in 1911, the annual increment of population being 1,630,252, equivalent to 19.45 per one thou- sand. The density of population in the Continental United States per square mile has increased since 1860 from 10.6 to 16.9 in 1880, and from 25.6 in 1900 to 32.1 in 1912. Comparing or contrasting the present population conditions of this country with other relatively well developed sections of the globe, we are far from having reached a point which can be considered particularly alarming, but it would certainly be a serious error to reason from general principles in a matter of this kind, since the problem of overpopulation, especially with reference to economic conditions, is always, in its final analysis, largely a local one. Thus, for illustration, the present density of Rhode Island is 508.5 persons per square mile; of Massachusetts, 418.8; of New Jersey, 337.7; of Connecticut, 231.3; and of New York, 191.2. For all of New England the density is 105.7, and for the Middle Atlantic States, 193.2. All of the available statistical information seems to justify the conclusion that the world's population in general, and of the more civilized countries in particular, is increasing at the present time at a more rapid rate than in earlier years — a condition largely the result of a persistent and considerable decline in the death rate, which is more than an offset to the observed decline in the birth rate. There are, of course, important exceptions to this conclusion, which has reference to vast continental aggregates rather than to some of even the largest political subdivisions of the same. In some of these the conditions of population growth are so seriously disturbed by migra- tion, immigration and emigration, and variations of fecundity and mortality due to racial distribution, that precise conclusions are hardly warranted in the present imperfect state of population and vital statis- tics. Forecasts of Population Growth Estimates of the future population of the United States have been many and in a number of instances they have been verified with remark- able accuracy when limited to a reasonable period of time. Darby, for illustration, in his "View of the United States," published in 1828, made a forecast of the white population, which for 1850 was placed by him at 20,412,000, and which was ascertained by the census to be 19,553,000. Many similar estimates have been sustained by subsequent experience, but as a rule the rate of fecundity has been taken too high, especially for the colored population, by writers basing their views upon the observed rate of increase of the negro population during a condition of slavery. Even DeBow conceded a diminishing proportion of negro population with an increase in aggregate growth in population fully sustained by subsequent experience. DeBow, in 1862, estimated the negro popula- tion of the United States for 1880 at 6,591,000, whereas by the census for that year the same was ascertained to be 6,580,000. All esti- mates of this kind are certain to fail if projected too far forward, but they are unquestionably approximately trustworthy for relatively short periods of time, and for many purposes are of considerable practical value. On the assumption, therefore, that the decennial rate of increase in the population growth of the United States will gradually diminish, partly because of a probable decline in immigration and a possible further reduction in the birth rate, the following forecast is included in this dis- cussion as a concrete illustration of the probable population conditions likely to exist in the continental United States within a measurable period of time. Population Estimate for the Continental United States, 1910-1960 Year Census Population Density per Sq. Mile 1910 91,972,000 30.93 1920 109,999,000 36.98 1930 130,019,000 43.72 1940 151,862,000 51.06 1950 175,248,000 58.92 1960 199,783,000 67.17 According to this table the approximate density of the United States by 1960, assuming a normal rate of increase during the intervening period, would only be sixty-seven persons per square mile, or about one-fifth of the present density of the German Empire. Granting that the immediate out- look for the future is not as alarming with us as with some other nations, it is self-evident that the social, economic and political problems result- ing from an augmentation in the number of inhabitants and the gradual accumulation of vast aggregates of people, aside from the mere problem of density itself, must be among the most serious conceivable, and therefore, as such, they are properly entitled to an extended critical and impartial consideration at the present time. Tendency to City Growth The trend of the population all over the civilized world is to-day towards the cities, which now contain a vastly larger number of inhab- itants than during any other period of time in recorded history. The problem of urbanization, from a historic, geographic and economic point of view, has been ably treated by Prof. Pierre Clerget, who in- cludes in his discourse estimates of population for ancient cities, which, however, are more or less conjectural. The same conclusion applies to the dissertation on the "Numbers of Mankind in Ancient and Modern Times," by Robert Wallace, published in Edinburgh in 1809, and the speculations of Sir William Petty, Gregory King, and others whose writings on population estimates were previous to the nineteenth century, which marks the dawn of modern census inquiries, or the accurate enu- meration of the numbers of mankind, for at least the civilized portion of the globe. Sufficient information, however, of a general nature is available to warrant the assumption that in earlier periods the propor- tion of urban population was much less than at the present time, and this certainly is true of the United States, for which we have accurate data since 1790. During the twelve inter-censal periods the proportion of urban population has constantly increased. The proportion of urban population (which term includes all incorporated places of 2,500 inhabit- ants or more) has increased from 29.5 per cent, in 1880 to 46.3 per cent, in 1910. During the last decade the urban population has increased 34.8 per cent., or in actual numbers 11,014,000, as against an increase of only 11.2 per cent, for rural territory, or 4,964,000. Rate of Natural Increase in Population The sanitary progress of civilized countries, to which primarily must be attributed the observed decline in the death rate, to be subsequently discussed in more detail, has naturally been more effective in the large cities than in the smaller communities or the strictly rural territory. Granting that the birth rate of cities is below that of rural sections, it is quite possible that there is a larger excess of births over deaths in modern cities in consequence of the remarkable results of sanitary administration and control. The annual excess of births over deaths varies, however, quite widely for the different countries, geographical subdivisions and cities of the world, and in some exceptional cases even in civilized countries the deaths may exceed the births, as is well known to be true of modern France. On the basis of the best estimate possible, the present rate of natural increase for the world as a whole is approximately 7.6 per one thousand of population, equivalent to an actual increase per annum of 13,260,000. This estimate is based largely on the registration returns of civilized countries having an aggregate population of 834,000,000 and an excess of births over deaths of 9.3 per annum. The birth rate for these countries is 34.3 per one thousand, and the death rate 25.0. The estimate, therefore, is quite conservative, and in all probability the actual increase is greater than that assumed. For the non-registration countries I have assumed an annual excess of births over deaths of only 5.8 per one thousand, which is considerably below the normal excess of births over deaths in the registration countries of Asia, which include nearly all of India, the Island of Ceylon, the French possessions in Cochin China and the Empire of Japan. For these four countries combined the natural increase per annum, or excess of births over deaths, is 7.3 per one thousand, or the annual difference between a birth rate of 38.4 and a death rate of 31.1. It seems a safe assumption that in the remainder of the world, for which information is not available, the probable rate of natural increase is about 5.8 per one thousand. With an annual increase of 7.6 per one thousand, assuming no further improve- ment in the general death rate, which, however, is most likely to occur, 10 the world's population may be expected to double itself in about ninety years. Since the death rates throughout the civilized, as well as the uncivilized world, are known to be generally declining, the rate of doubling the population is quite possibly to be achieved in even a shorter period of time. A summary statement of the estimated natural increase of the world's population is given in the table below : Estimated Annual Natural Increase of the World's Population as Based on the Most Trustworthy Registration Returns for Recent Years, Chiefly for 1911 Estimated Annual Estimated ■n .■ . j Estimated Estimated Natural Actual Continents fcstirnatea Nq of No _ of Increase Annual Population B;rths Deaths per 1,000 Natural of Popu- Increase lation Europe 463,997,000 15,545,640 10,657,220 10.5 4,888,420 Asia 962,233,000 37,306,800 31,753,670 5.8 5,553,130 Africa. 135,987,000 5,279,140 4,348,324 6.8 930,816 North America.. 127,993,000 3,495,400 2,286,800 9.4 1,208,600 South America. . 51,193,000 1,950,940 1,368,150 11.4 582,790 Australasia 7,572,000 214,718 118,071 ,12.8 96,647 Total* 1,748,975,000 63,792,638 50,532,235 7.6 13,260,403 *The world's birth rate is estimated at 36.5, and the death rate at 28.9, per one thousand of population. Declining Death Rates of Civilized Countries It is only for comparatively recent periods that trustworthy vital statistics are available for a considerable portion of the world with local climatic, racial or other conditions sufficiently varied to disclose the approximate range in the rate of mortality and the evidence of its reduction or increase, as the case may be. For the registration area of the world the mortality rate at the present time is approximately 25.0 per one thousand per annum, which is considerably in excess of the death rate for the more important civilized countries, such as, for illus- tration, the German Empire, where the rate is 17.3; England and Wales, 14.6; France, 19.6; United States, 14.7; and the Commonwealth of Australia, only 10.7. These comparatively low death rates contrast with the still prevailing excessive death rates of certain other countries, as, for illustration, 23.7 per one thousand for Spain, 25.0 for Hungary, 30.5 for Russia, 31.1 for Mexico, 33.2 for India, and 40.9 for twenty cities of Egypt. During the last thirty years, however, the general death rate in most of the principal countries of the world has declined, but since the evidence in detail does not permit of a convenient summary 11 discussion, the following comparisons are limited to the two five-year periods ending respectively with 1885 and 1910. The observed decrease in the rate is, in each case, the reduction per one thousand of popula- tion, carefully calculated on the basis of available census returns.* During the thirty years under observation the general death rate de- clined in the Australian Commonwealth from 15.7 to 10.7; in Austria, from 30.1 to 22.3; in Denmark, from 18.4 to 13.7; in England and Wales, from 19.4 to 14.7; in Finland, from 22.2 to 17.4; in France, from 22.2 to 19.2; in the German Empire, from 25.3 to 17.9; in Hungary, from 33.1 to 25.0; in Ireland, from 18.0 to 17.3; in Italy, from 27.3 to 21.0; in the Netherlands, from 21.4 to 14.3; in New Zealand, from 10.9 to 9.7; in Norway, from 17.2 to 13.8; in Scotland, from 19.6 to 16.1; in Spain, from 32.6 to 24.3; in Sweden, from 17.5 to 14.3; and, finally, in Switzerland, from 21.3 to 16.0. For a few of these countries the decline in the rate has not been of much actual importance, but in practically all of the countries the tendency of the death rate during the last thirty years has been persistently downward, and the present indications are that there has been a still further decline in the rate during the last three years. Combining the mortality of the principal civilized countries, there has been a general reduction in the crude death rate from 25.09 per one thousand during the five years ending with 1885 to 19.26 per one thousand during the five years ending with 1910, an actual decrease of 5.92 per one thousand, equivalent to 23.2 per cent. The relative decrease in the rate has been most pronounced in the Netherlands, where the present rate is only 63 per cent, of the rate prevailing thirty years ago. The corresponding figure for the registration area of the United States is 76 per cent.; and for a few other countries, respectively, England and Wales, 71 per cent.; Denmark, 71 per cent.; Belgium, 72 per cent.; the Australian Commonwealth, 71 per cent.; Finland, 66 per cent.; German Empire, 72 per cent.; Italy, 71 per cent.; and Switzerland, 67 per cent.f It requires to be said in this connection that the foregoing rates are not corrected or standardized for variations or changes in the age and sex constitutions of the respective populations considered. Such correc- tions would have involved much labor, with but a slight probability that the resulting conclusions would have been materially modified. The results are verified and otherwise sustained by numerous special- ized mortality studies on the basis of scientifically constructed life tables *The international vital statistics are derived most conveniently from the annual reports of the Registrar- General of England and Wales. fThe remarkable uniformity in the rate of mortality decrease for representative countries during the last thirty years suggests that the diminution is the result of more or less uniformly operating causes making for the deliberate reduction of the death rate in consequence of practically identical methods in sanitary adminis- tration and persistent progress in the practice of medicine, surgery and personal hygiene. 12 CD I 00 00 +-* <0 Q) O Id i_ CD C a> CD n» 3 a. o a. o o o a ■H 0£ •F id a « 0> BM/lfflONOOlSMIinNS- ■*•*•*-* -*cocic\iwcyovic\JCM— oi {\JC\llMC\IC\IC\JC\IC\ICNC\lo — O) OT OT.O OOOOOOOOO cocDooooa3OTCDO>a>a>oo'a)a)CT>o r ' ix od od ix rx ix id ^ cmojimoicmcmcmcmcmcmcmcmcucmcmcm — (MC0-*iniD|x0D00O — fMCO-4-LOCD ooooooooooooGDOoaoo^oooocnooooo) ODGOO0O000O00OO0O0O000OOOD00OOO0 • - 13 for the more important countries and geographical subdivisions of the world, particularly the German Empire and its constituent states, England and Wales, the Australian Commonwealth, New Zealand, etc. The observed decline in the general death rate and the corresponding in- crease in human longevity may, therefore, safely be accepted^ as a world phenomenon, and granting this, it is difficult to conceive of a more im- portant conclusion affecting the future wellbeing of all mankind. Decline in the Death Rate of the United States In the foregoing discussion no reference has been made to the statistics in detail for the United States, since for the earlier period no data are available which would be strictly comparable with those of recent years. Most of the following observations are, therefore, limited to the decade ending with 1910, for which the registration returns are, broadly speaking, representative for the country at large. Comparing the five-year period ending with 1905 with the corresponding period ending with 1910, there has been a decline in the general death rate from 16.2 to 15.1 per one thousand. In the table following are brought together the official statistics for the United States from 1880 down to 1913, when the rate was only 14.1 per one thousand of population. Taking the approximate rate for 1880 as one hundred, the corresponding rate for 1913 was only seventy-one. In part, of course, it is quite probable that the decline in the mortality has been slightly affected by the large immigration during the last thirty years, but in a general way the evi- dence is conclusive that the reduction in mortality is the result of a nation-wide improvement in sanitary conditions and increasing effective- ness of federal, state and municipal sanitary control. General Death Rate of the United States Registration Area, 1880-1913 Year Population Deaths Rate per 1000 1880 8,538,000 169,060 19.8 1890 19,659,440 386,212 19.6 1900 30,765,618 539,939 17.6 1905 34,094,605 545,533 16.0 1910 53,843,896 805,412 15.0 1911 59,275,977 839,284 14.2 1912 60,427,133. 838,251 13.9 1913 63,299,164 890,823 14.1 Reduction in Death Rate, by Age and Sex Information is fortunately available for the United States registration area of 1900 to establish with approximate accuracy the changes in the 14 death rate, by divisional periods of life during the intervening decade, ending with 1911. The table following has been derived from Bulletin No. 112 of the Division of Vital Statistics of the Bureau of the Census. The table exhibits the death rates per one thousand of population at specified age periods and the percentage which the death rate in 1911 represents of the rate prevailing in 1900, with the required distinction of sex: The Comparative Death Rate of the United States Registration States by Divisional Periods of Life, 1900-1911 Death Rate(*) per 1,000 Population for States (f) Rate iri 1911 Included in Registration Area in 1900 Represents of AGE GROUP 1911 1900 That in 1900 Both Pe- Both Fe- Both Fe- Allages: Sexes Males males Sexes Males males Sexes Males males Crude rate 14.9 15.8 14.0 17.2 17.9 16.5 87 88 85 Corrected rate (|) .. 14.6 15.3 13.9 17.0 17.6 16.5 86 87 84 Under 5 years 36.6 39.8 33.3 49.9 54.1 45.7 73 74 73 Under 1 year 125.5 138.6 112.1 161.9 178.4 145.0 78 78 77 lto 4 years 12.8 13.3 12.2 19.8 20.4 19.1 65 65 64 5 to 9 years 3.2 3.4 3.1 4.7 4.7 4.6 68 72 67 10 to 14 years 2.2 2.4 2.1 3.0 2.9 3.1 73 83 68 15 to 19 years 3.5 3.7 3.3 4.8 4.9 4.8 73 76 69 20 to 24 years 5.0 5.3 4.7 6.8 7.0 6.7 74 76 70 25 to 34 years 6.3 6.7 6.0 8.2 8.3 8.2 77 81 73 35 to 44 years 9.4 10.4 8.3 10.3 10.8 9.8 91 96 85 45 to 54 years 14.5 16.1 12.9 15.0 15.8 14.2 97 102 91 55 to 64 years 28.4 30.9 26.0 27.3 28.8 25.8 104 107 101 65 to 74 years 58.3 61.6 55.1 56.5 59.5 53.7 103 104 103 75 years and over 143.0 147.4 139.2 142.4 145.9 139.3 100 101 100 * Exclusive of stillbirths. t Group includes Connecticut, the District of Columbia, Indiana, Maine, Massachusetts, Michigan, New Hampshire, New Jersey, New York, Rhode Island and Vermont. % Based on the standard million of England and Wales, 1901. The foregoing table emphasizes the fact, not generally known or thor- oughly understood, that the observed decline m the American death rate has been chiefly at ages under thirty -five, and that at ages thirty- five to forty-four, for illustration, the relative rate for 1911 was 91 per cent, of the rate for 1900; at ages forty-five to fifty-four, 97 per cent.; at ages fifty -five to sixty-four, 104 per cent.; at ages sixty- five to seventy -four, 103 per cent.; and at ages seventy -five and over it was 100 per cent. In other words, at ages fifty-five and over the death rate has actually increased, which is the more significant when the relatively considerable decrease at the earlier ages is taken into account. 15 Decline in the Death Rate by States The next table shows the decline in the death rate corrected for age in the several registration states of the United States as existing in the year 1900: Comparative Death Rates by States, 1900-1911 Corrected(*) Death Rate per Rate in 1911 1,000 Population Represents of AREA 1911 1900 That in 1900 Both Fe- Both Fe- Both Fe- Sexes Males males Sexes Males males Sexes Males males States included in regis- tration area of 1900 14.6 15.3 13.9 17.0 17.6 16.5 86 87 84 Connecticut 14.8 15.7 14.0 17.4 18.1 16.7 85 87 84 District of Columbia. 18.9 20.8 17.2 24.4 26.1 22.6 77 80 76 Indiana 12.3 12.4 12.2 14.4 14.2 14.6 85 87 84 Maine 13.0 13.3 12.6 14.9 14.7 15.0 87 90 84 Massachusetts 15.0 16.0 14.1 18.1 19.0 17.3 83 84 82 Michigan 12.4 12.9 12.0 13.9 14.0 13.8 89 92 87 New Hampshire 14.2 14.7 13.8 16.3 16.4 16.3 87 90 85 New Jersey . 15.1 16.1 14.3 18.2 19.3 17.0 83 83 84 New York 15.7 16.7 14.8 18.3 19.1 17.4 86 87 85 Rhode Island 15.7 16.8 14.8 20.9 21.6 20.2 75 78 73 Vermont 12.6 12.7 12.5 13.8 13.7 13.9 91 93 90 * Corrected on basis of standard million of England and Wales, 1901. The table is self-explanatory and requires no discussion, but it may be pointed out that there has been a decrease in the death rate cor- rected for age in all of the registration states, but to a variable degree, the decline for both sexes combined having been greatest in the State of Rhode Island and least in the State of Vermont.* Decline in the Death Rate of Cities The evidence of a declining death rate is still more conclusive and suggestive for the large cities of the United States and of other civilized countries of the world. Combining all of the American cities for which trustworthy data were* available in 1870, the rate for that year was 25.5 per one thousand, which by 1872 had increased to 28.6; by 1890 *The following table exhibits the changes in the age distribution of the population of the United States on a percentage basis, showing respectively for the several census years the proportionate population at ages under 5, 5 to 64, and 65 and over since 1880. The observed changes can not be considered sufficient to seriously impair the conclusion that the crude death rate of the registration area indicates with approximate accuracy the mor- tality tendency of the United States during the last thirty years. Percentage Distribution by Age Periods of the Population of the United States 1880-1910 1880 1890 1900 1910 Ages % % % % 0-4 13.8 12.2 12.1 11.6 5-64 82.8 83.9 83.8 84.1 65-over 3.4 3.9 4.1 4.3 All ages 100.0 100.0 100.0 100.0 16 CD CD CO CD c «J p 'i_ CD E < 4- O a> (0 DC CO CD Q "co L_ CD c CD CJD / \ J / f c / / ( / \ \ Js con cm od co" co ifl or> — -tf cd — ao in co N N (D CD N N k S, N N N 10 Ul (i 1/1 o Q- o NCOOio-c\in-^Lnu)NCOcoo- cnrocnoooooooooo — — 00CD00CnQ0a>O)O)O>QOQO'O>O>(D00 o o Q. -a>(J)(T3O000O> ooaooooooooooococoaooooocooooooo X "a 1 17 the rate had declined to 21.8; by 1900 to 18.8; by 1910 to 16.5; and by 1911 to 15.6. The evidence already available seems to prove that the rate for 1912 was the lowest on record. The rate for recent years is based upon the combined returns for fifty cities, with an aggregate pop- ulation of nearly twenty millions.* During the last thirty years the death rate of large cities of this and other countries has declined as follows, the comparison being limited to the quinquennial periods ending respectively with 1885 and 1910. The death rate of London decreased from 20.9 to 14.0 per one thousand; of Dublin, from 27.5 to 21.6; of Paris, from 24.4 to 17.5; of Amsterdam, from 25.1 to 13.1; of St. Petersburg, from 32.8 to 25.5; of Berlin, from 26.5 to 15.5; of Vienna, from 28.2 to 17.0; of Budapest, from 31.5 to 19.5; of Milan, from 30.3 to 19.3; of Melbourne, Victoria, from 20.1 to 13.1; of Sydney, New South Wales, from 20:8 to 10.5; of New York, from 27.5 to 17.0; of Chicago, from 21.5 to 14.5; and of Philadelphia, from 22.3 to 17.7. This comparison is exceedingly instructive, emphasizing, as it does, on the basis of trustworthy data, the conclusion that the decline in the death rate is world-wide and that in practically all the large centers of population the rate has declined, the decrease varying from approxi- mately one-fifth to one-third or more during the thirty-year period, with definite indications of a further reduction in the rate since 1910 in nearly all the localities, states and countries considered in the pres- ent discussion. Improvements in the Longevity of Primitive Races The foregoing conclusions are based entirely upon the returns for civilized countries with well-established sanitary departments and effec- tive statutory requirements providing methods and means of sanitary control. Evidence, however, is also available for the so-called non- civilized countries of the world to warrant the conclusion that the longev- ity of primitive races is increasing and that the conditions favorable to the acclimatization of white races in the tropics are constantly and rapidly improving. This conclusion applies particularly to the vast areas inhabited by the primitive or non-European races of Asia, chiefly of China, Formosa, the English and Dutch East Indies, Ceylon, the Straits *The death rate of the registration area for the year 1912 was 13.9 per 1,000. During 1913 the rate increased slightly, to 14.1. The rates for the five principal cities down to 1913 were as follows: Death Rates of Large American Cities, 1901-1913. (Rate per 1,000) Years New York Chicago Philadelphia St. Louis Boston 1901-05 19.0 14.5 18.1 17.9 18.8 190S-10 16.9 14.9 17.7 15.6 17.9 1911 15.2 14.5 16.6 15.4 17.1 1912 14.5 14.8 15.3 14.9 16.4 1913 14.3 15.1 15.7 14.9 16.4 From Preliminary Announcement of Division of Vital Statistics, U. S. Censu9 Office, May 19, 1914. 18 Settlements and Siam. The conclusion also applies to most of the European possessions in Africa and to vast territories in South and Central America and Australia. For India the evidence is quite con- clusive that a material improvement is taking place in the health of the people, which is best illustrated by the statistics of European troops since the beginning of the nineteenth century. The death rate has declined from 84.6 per one thousand during the period 1801-30 to 19.3 during the decade ending with 1879, a further reduction having taken place during the subsequent period, the rate for 1901-05 having been 12.2; for 1906-09, 8.7; and, finally, for 1911 the rate was only 4.9. A corresponding decrease in the death rate of native troops has taken place, but limiting the discussion to recent years, it declined from 10.0 during 1901-05 to 6.5 during 1906-09, and to 4.5 during 1911. These are exceptionally encouraging statistics, which have their most interesting parallel in the remarkable sanitary achievements in the American administration of the Panama Canal Zone under the efficient direction of Colonel C. W. Gorgas. During the French administration, 1881-90, the average death rate of the Isthmian Canal employees was 61.3 per one thousand. During the American administration, 1904-12, the average rate was only 16.3; and during the last year of the period, only 9.2 — an achievement probably without a parallel in sanitation history. The annual death rate of the city of Panama in 1887 had reached the almost incredible proportions of 121.7 per one thousand, but the rate has gradually been reduced until in 1912 it was only 29.3. As another interesting illustration of the observed decline in the death rate of tropical countries, a reference may be made to the mortality of non- native British officials in West Africa since 1905, the rate having been reduced from an average of 28.1 per one thousand during that year to 17.3 by 1909, and to only 12.4 by 1912.* At the same time, there has been an increase in the average length of service from three years and six months in 1905 .to six years and three months in 1912; and a substantial reduction was also obtained in the rate of invaliding, from 62.3 per one thousand in 1905 to only 28.2 in 1912. The death rate of Algeria, which was once considered extremely unhealthful, has been reduced to 19.6 per one thousand in 1911, and a large portion of the country has become a health resort for Europeans. The death rate of Madagascar in 1911 was 26.5 per one thousand, and of Cochin China, 26.2. *See also the Reports for 1912 on Blackwater Fever in the Tropical African Dependencies, Published as Par- liamentary Paper Cd. 7211, London, 1914. Also "Medizinal-Berichte uber die Deutschen Schutzgebiete," published Berlin, 1913, including reports on all the German Colonies, with extended observations on tropical diseases and the mortality of Europeans. Interesting in this connection is the Statistical Analysis of the Mor- tality of Scandinavian Missionaries in the Congo Free State, 1878-1904. That the improved tropical mortality is also reflected in the experience of life insurance companies transacting business in tropical countries is brought out by a paper on the subject in the Proceedings of the Actuarial Society of America for 1908, by Arthur Hunter, with an extended discussion by other members of the society. 19 In the West Indies the death rates are diminishing, the rate for Cuba being only 14.7 per one thousand; for the Dutch West Indies, 16.9; for Guatemala, 18.5; for Honduras, 18.7; for Salvador, 22.^8; and British Guiana, which in former years had a very high death rate, has now a rate of only 31.7, whereas for Venezuela the rate for 1911 was 20.3. All of these rates may safely be accepted as evidence of a gradual diminution in the mortality of so-called non-civilized or only partly civilized countries largely inhabited by primitive or other than white races living chiefly in the temperate zone.* Sanitary Progress of Tropical Countries A truly vast amount of instructive information is available for so- called uncivilized countries illustrating the sanitary progress which is being made, largely, of course, in consequence of the white man's conquest of tropical regions, and which is bound, in course of time, to afford almost inconceivable opportunities for settlement and the rational develop- ment of natural resources. Attention may properly be directed on this occasion to the annual reports on the moral and material progress and condition of India, of which the fifty-eighth was published during the present year; the report of the International Plague Congress, held at Mukden in April, 1911, which constitutes one of the most notable contributions to epidemiology; the annual medical reports on the German Colonial Possessions; the reports of the Advisory Committee of the Tropical Diseases Research Fund; the proceedings of the Inter- national Conference on the Sleeping Sickness, the English reports on Blackwater Fever in Tropical African Dependencies; the scientific re- ports of the Wellcome Tropical Research Laboratories in Khartoum, Egypt; the scientific publications and special local investigations in tropical countries of the tropical medical schools in Liverpool, Hamburg, Townsville (Queensland), London and New Orleans. Mention also requires to be made of the excellent report of Prof. W. J. Simpson on sanitary matters in various West African Colonies and on the outbreak of plague on the Gold Coast. For all of the British and German West African colonies thoroughly scientific reports are now being published, which, without exception, reflect the evidence of more or less rapid strides in necessary sanitary reforms. The late Sir Hubert Boyce has admirably reported upon the health progress in administration in the West Indies; and the Japanese Government has brought about a veritable hygienic revolution in the administration of Formosa, particularly in the reduction *The mortality statistics for Central and South America require of course to be accepted with extreme cau- tion. The favorable conclusions regarding the decline in the South and Central American death rates are based upon an extended study of the facts, with particular reference to Yellow Fever and Malaria. A full discussion of the mortality of the Western Hemisphere is reserved for future consideration. 20 of the incidence of malaria. All of these efforts, which are but a mere fragment of what is actually being done in the sanitary administration of Colonial possessions throughout the world, including the Philippines,* Hawaii and Porto Rico, indicate a gradual reduction in the mortality from preventable diseases among both native and white races in the tropics. The inevitable consequence must be a larger rate of natural increase and a proportionately more rapid augmentation of the popula- tion of those sections of the globe which constitute to a not inconsid- erable extent the future sources of the world's food supply, f The Principal Causes of Death The human death rate is the resultant of a large number of known or unknown, obvious or obscure, causes and conditions destructive to human life. Many of these causes are now known to be preventable and subject to administrative control. The immediate or remotely contrib- utory causes of death are comparatively few and simple among primi- tive races and relatively numerous and complex among civilized mankind. The hygiene of transmissible diseases is a modern branch of medicine, based upon the epoch-making discoveries of Koch, Pasteur, Ross, Reed, and others whose work has been of incalculable benefit to all mankind. Cholera, malaria, plague, smallpox, typhoid fever and yellow fever are no longer a serious menace to civilized countries, since their nature and mode of transmission are thoroughly understood, and preventive measures are applied with increasing effectiveness, and in some cases with absolute certainty, as is well illustrated in the history of recent sporadic outbreaks, or the occurrence of isolated cases of plague and leprosy on the East and West coasts of the United States. The best known of these diseases, typhoid fever, has gradually been reduced from an average rate of 35.9 per one hundred thousand during 1900 to 16.5 during 1912. In the United States during 1911 the ten principal causes of death, accounting for 66.6 per oent. of the mortality from all causes, were, in the order of their importance, organic diseases of the heart (10.0 per cent.), tuberculosis of the lungs (9.7 per cent.), *A practical illustration of the methods of sanitary administration in the Philippines is the "Sanitary In- spector's Handbook," published by the Bureau of Health of the Department of the Interior of the Government of the Philippine Islands. Also the Special Report of Dean C. Worcester on the History of Asiatic Cholera in the Philippine Islands, published in 1909. The progress which is being made in the control of Beri-Beri is best illustrated in the Studies of the Institute for Medical Research of the Federated Malay States, published in 1911, and the monograph on the Etiology of Beri-Beri by Frazer and Stanton, derived from the same source and re- printed in the Philippine Journal of Science for 1910. For a more extended study of this important subject, with particular reference to the diagnosis and prevalence of the disease, the elaborate Treatise on Beri-Beri by Edward Vedder, M. D., published by William Wood & Co., 1913, should be consulted. In 1912 there were twelve deaths from Beri-Beri in the registration area of the United States, but there are convincing reasons for believing that the disease is much more prevalent than is generally known. "("Indications of health progress in arctic regions are to be found in the Medical Handbook for the Alaska School Service, issued by the United States Bureau of Education in 1913, and the Special Reports of the United States Public Health Service on Tuberculosis among Eskimos. A material improvement in the health condi- tions of the population of Labrador and the northern outposts of Newfoundland has resulted from the admir- able work of the Grenfell Medical Missions at Battle Harbor and other far northern points. 21 acute nephritis and Bright's disease (6.9 per cent.), accidents and homicides (6.4 per cent.), pneumonia (6.3 per cent.), respiratory diseases other than pneumonia and tuberculosis of the lungs (5.Q per cent.), con- genital debility and malformations (5.6 per cent.), diarrhoea and enter- itis, under two years, (5.5 per cent.), cerebral hemorrhage and softening of the brain (5.4 per cent.), and, finally, cancer and other malignant diseases (5.2 per cent). In marked contrast, the mortality of India during the same year was chiefly the result of six principal causes, being, in the order of their importance, fevers, accounting for 55.0 per cent., plague for 9.6 per cent., cholera for 4.6 per cent., dysentery and diarrhoea for 3.5 per cent., respiratory diseases for 3.1 per cent., and smallpox for 0.8 per cent. The six groups of causes combined accounted for 76.6 per cent, of the mortality of India from all causes. India Medical Statistics The general death rate of the registration area of the United States in 1911 was 14.2 per one thousand, while the corresponding rate for the registration area of India was 32.0. The combined fever death rate, including typhoid, typhus and malaria, was only 2.4 per ten thousand of population for the United States, against 176.3 for India. If, there- fore, in the course of time the fever-problem in India can be solved along much the same lines as has been the case in some other tropical countries, the general death rate of the Far East would be reduced to perhaps one- half of its present proportions. Astonishing medical and sanitary progress has been made in India, as is evident from the numerous official and other accounts, but mention can here only be made of the proceedings of the Second All-India Sanitary Conference, held at Madras in 1912, and the report on investigations into the causes of malaria in Bombay to give emphasis to the conclusion that a material reduction in the fever death rate of India will unquestionably be brought about within another generation. The problems awaiting solution are truly of colossal proportions, complicated, as they are, by the economic condition of the people, their exceptional racial and religious distribution, the pro- found adherence to caste and custom, etc. Should this expectation be fulfilled, the present small natural increase of India of only 6.58 per one thousand of population, or the annual difference between the birth rate of 38.59 and the death rate of 32.01, could easily be doubled, or in any event be made to attain the normal average for fairly well civilized coun- tries, of approximately ten per one thousand per annum. If, in addition thereto, the cholera mortality of India, which now accounts for about three hundred and ninety thousand deaths per annum, and the even larger annual mortality from plague could be brought under control and materially reduced, it is self-evident that there are almost inconceivable possibilities for a much more rapid increase in the population of India and other countries of the Far East than have prevailed in historic periods of time. Reduction in the Death Rate by Causes An extended consideration of the diminution in the death rate from specified causes would unduly enlarge the present discussion. The following observations are therefore limited to the registration area of the United States, which may be accepted as fairly typical of other civilized countries of the world. The rates are limited to the two quinquennial periods ending respectively with 1905 and 1910, since no earlier comparative data are conveniently available for the registration area of this country. The rates for specified causes are given on the basis of one hundred thousand population. For the principal causes the reduction during the last five-year period, compared with the first, has been as follows: typhoid fever has been reduced from 32.0 to 25.6; smallpox, from 3.4 to 0.2; diphtheria and croup, from 29.6 to 22.4; influ- enza, from 19.9 to 16.4; purulent infections, from 6.1 to 3.8; tetanus, from 3.5 to 2.7; tuberculosis, all forms, from 192.6 to 168.7; chronic rheumatism and gout, from 3.6 to 2.2; alcoholism, chronic and acute, from 6.1 to 5.8; meningitis, from 31.7 to 19.4; softening of the brain, from 3.7 to 2.5; paralysis (not otherwise specified), from 20.1 to 16.1; general paralysis of the insane, from 6.8 to 5.5; epilepsy, from 4.4 to 4.2; convulsions of infants, from 21.4 to 12.8; neuralgia and neuritis, from 6.9 to 5.5; non-tubercular respiratory diseases, from 220.5 to 188.1; and, finally, diseases of the skin, from 7.3 to 6.1. With practically no im- portant exception the death rates for these eighteen specified and all more or less important causes, which account for 33.6 per cent, of the mortality from all causes during the five-year period ending with 1910, have undergone a further reduction during 1911 and 1912. Causes of Death Which Are on the Increase The only important causes of death which have increased f during the five years ending with 1910, as compared with the previous five years, There are no better illustrations of sanitary progress in its relation to population increase than the reports of sanitary conferences in the different provinces of India. The Report of the Punjab Sanitary Conference, held under date of August, 1913, includes an extended consideration of such important questions as rural sanitation, town-planning, sanitation in connection with schools and the problem of control in the case of specific diseases, particularly malaria, tuberculosis, plague and cholera. After calling attention to the reduction in the urban death rate in the Punjab, amounting to about 4.5 per one thousand of population, it is calculated that this reduc- tion is equivalent to the saving of some 8,700 lives every year in the municipal towns, which would otherwise have been sacrificed. It has been pointed out in this connection in a review of the census of India for 1911, by Sir J. A. Baines, that half the net increase in the population of India during the past decade took place in subdivisions which had less than 150 persons per square mile, and very little of it in those which had over 450; a substantial reduction in the death rate of large centers of population must therefore result in a considerable additional increase in population. 'fTwo important diseases which have increased, though as yet numerically of relatively small importance, considering the country as a whole, are anterior poliomyelitis and pellagra. There are few more instructive illus- trations of the thoroughly systematic manner in which public health activities are now administered than the highly specialized studies which have been made of the epidemiology of infantile paralysis. See particularly in this 23 are briefly the following: syphilis increased from 4.1 to 5.4 per one hundred thousand of population; cancer and other malignant turners, from 67.9 to 72.6; diabetes, from 11.5 to 13.7; locomotor ataxia and other diseases of the spinal cord, from 7.3 to 8.4; all diseases of the circulatory system combined, from 161.2 to 177.7; ulcers of the stomach, from 2.9 to 3.6; diarrhoea and enteritis, under two years, from 89.0 to 96.2; diseases of the puerperal state, considered as a group, from 14.2 to 15.5; malformations, chiefly congenital, from 12.2 to 14.9; diseases of early infancy, chiefly congenital debility and premature births, from 73.9 to 75.0; suicide, from 13.9 to 16.0; accidents, from 84.9 to 86.0; and, finally, homicide, from 2.9 to 5.9. In some cases, no doubt, the changes are the result of improved medical diagnosis, and, still more, the consequence of changes in methods of death classification, but this objection is not likely to impair materially any of the foregoing general conclusions. Combining the thirteen prin- cipal diseases which have increased, the resulting total death rate was 536.9 per one hundred thousand for the first five years, against 590.3 for the last. The actual increase in this group of causes was, therefore, equiv- alent to 53.4 per one hundred thousand of population, or the average combined death rate from the thirteen causes during the last five years was 9.9 per cent, in excess of the rate during the first five-year period under consideration. Combining the eighteen principal diseases which have decreased, the resulting total death rate was 619.6 per one hundred thousand for the first five years, against 508.1 for the last. There was, therefore, an actual decrease in this group of causes equivalent to 111.5 per one hundred thousand of population, or 18.0 per cent. Of the diseases which have decreased, the most important are un- questionably typhoid fever, diphtheria and croup, tuberculosis of the lungs and non-tubercular respiratory diseases. Since most of these are of the strictly preventable class, there are the strongest reasons for believing that a still further, and substantial, reduction in the death rate, at least of civilized countries, will be obtained in the near future, and that as a result of such diminution the excess of births over deaths will be increased. connection BulletinNo. 90 of the Hygienic Laboratory of the United States Public Health Service, and the Special Report on Infantile Paralysis of Massachusetts, in 1909, published by the State Board of Health. See also the results of Investigations on Epidemic Infantile Paralysis, published in English, by the State Medical Institute of Sweden, and the Reports and Papers on Epidemiologic Poliomyelitis, published by the Local Government Board, London, 1912, Even more extended attention has been given to the subject of pellagra, the mortality of which in the regis- tration area for 1912 amounted to 674. The disease is apparently on the increase throughout the south- ern states. A concise summary of the epidemiology of pellagra has been published, as reprint No. 120, by the United States Public Health Reports, Washington, 1913. Another new disease is spotted or tick fever of the Rocky Mountains, which has become a problem of great interest to the physicians, zoologists and sanitarians. The report on the subject by Dr. John F. Anderson has been published as Bulletin No. 14 of the Hygienic Laboratory of the United States Public Health Service, Washington, 1903. 24 Problems of Cellular Pathology Momentous questions arise out of these considerations, which can not be adequately considered, even in part, in the remaining portion of this address. The economic aspects of the problem are of the first order of importance and less difficult of discussion than the more involved bio- logical questions, which are largely beyond my own understanding. In a most interesting summary account of the nature, origin and maintenance of life, Prof. E. A. Schafer has brought forward much apparent evi- dence that the dividing line between animate and inanimate matter is less sharply drawn than has hitherto been believed and that the elements com- posing living substances are few in number — chiefly carbon, hydrogen, oxygen and nitrogen. He therefore concludes that it is not a hopeless anticipation that the possibility of the production of living material is not as remote as is generally assumed. These views have not been generally accepted, and among others, not by H. E. Armstrong and Sir William Tilden, who are of the opinion that Prof. Schafer 's address "leaves us exactly where we were." Even if it is conceded that the problem of the origin of life is at root a chemical one and that carbon stands alone among the elements which condition the functions of the living sub- stance, it is an incontrovertible fact, in the words of Armstrong, that "Organic growth is clearly a process of extreme complexity, one that involves the association by a variety of operations of a whole series of diverse units." Of the vast strides which have been made by all the sciences during the nineteenth century, none have been more astonishing than those in the domain of biology, foremost among the new discoveries of which is the cell structure of plants and animals, which has given rise to a new branch of knowledge, known as "Cellular Pathology." It has properly been observed that a new era was entered upon with the dis- covery of protoplasm and the promulgation of the cell theory, as the result of refined methods in microscopical research. It has been estab- lished that the cell "is a microscopic chemical engine where the energy of the food-stuffs is finally set free and applied to the work of life." In proportion as the nature and the function of the cell become better understood the factors of control in the duration of life are obviously in- creased, and assume, in fact, almost inconceivable proportions. The dis- covery of the functions of the hormones, or chemical agents circulating in the blood, by means of which the activities of the cells constituting our bodies are controlled, and their relations to the internal secreting glands, the uses and importance of which were not understood until within recent years, foreshadows a time when many of the now obscure diseases will also be brought under control, with a consequential further improve- ment in the duration of life. This conclusion applies particularly to 25 the functions of the thyroid and parathyroid glands, the pituitary gland, which is a small structure no larger than a nut attached to the base of the brain, and the suprarenal glands, which are adjacent to the kidneys. Human life, in the words of Schafer, "is an aggregate life; and the life of the whole is the life of the individual cells." The first condition of the maintenance of the life of the aggregate is fulfilled by insuring that the life of the individual cells composing it is kept normal; the second essential condition for the maintenance of life of the cell aggregate being the coordination of its parts and the due regulation of their activity so that they may work together for the benefit of the whole. From this point of view the vast domain of cellular pathology assumes the greatest possible practical importance, and it is an encouraging indication of medical progress that increasing attention is being given to this subject.* Problems of Age, Growth and Death The most important practical contribution to the problems which arise out of the foregoing considerations is the work by Charles S. Minot on "Age, Growth and Death." Minot discusses the condition of old age, the cellular changes of age, the rate of growth, differentiation and rejuvena- tion, regeneration and death, the four laws of age, the longevity of animals and a new theory of life. Some of his observations are exceed- ingly suggestive, particularly those on the rate of growth, which un- fortunately fail in the required support of adequate statistical data for man, though, as pointed out by Minot, if statistics of the growth of man could be gathered with due precautions, "it would fill one of the gaps in our knowledge which is lamentable." The important and almost startling conclusion of Minot on the rate of growth may be briefly summed up in the statement that the period of youth is the period of most rapid decline in the rate of growth and that the period of old age is that in which the decline in the rate of growth is slowest. He em- phasizes the originally enormous power of growth in the embryo and the rapid proportionate decline almost immediately after birth. He therefore argues that it is not from the study of the old, but from the study of the very young, of the young embryo and of the germ, that we are to expect an insight into the complicated questions which con- front the "seeker after truth in the innermost secrets of the problem of life and death. *The literature of life pathologically considered is quite extensive. Perhaps the most comprehensive re- view of the whole subject is the "Wonders of Life," by Ernst Haeckel, published in 1905. The address on "Life: Its Nature, Origin and Maintenance," by Prof. E. A. Schafer, was published by Longmans, Green & Co., London, 1912. The essay on "The Origin of Life," by H. E. Armstrong, was republished in the Smithsonian Report for 1912. The biological essays on "The Mechanistic Conception of Life," by Jaques Loeb, M. D., were published by the University of Chicago Press, in 1912. The observations and conclusions of Charles Sedgwick Minot on "Modern Problems of Biology," originally delivered in the form of lectures at. the University of Jena, in December, 1912, were republished by Blakiston's Son & Co., Philadelphia, 1913. The more popular aspects of the problem have been made available in the treatise by H. W. Conn, in the story of "The Living Machine," published in New York, in 1899, and "Disease and Its Causes," by W. T. Councilman, in the Home Univer- sity Library of Modern Knowledge, 1913. The Problem of Old Age For immediately practical purposes, however, the study of old age will continue to attract attention, and deservedly so. No one has written to better purpose on the means available for the deliberate prolongation of life than Sir Herman Weber, whose treatise includes observations on the natural duration of life, the effects of an unfavorable heredity, the value of respiratory exercise, the importance of great moderation in food, the scientific aspects of the alcoholic and neurotic affections, and, finally, the psychology of old age. In a still more recent work on the care and treatment of old age, in health and disease, Robert Saundry, M.D., thoroughly covers the entire field, and following an im- portant introduction on the duration of life, based upon the fundamental concept that senility is not identical with old age, or that, in other words, the problem of longevity is not merely one of a quantitative increase in duration, but also one of a qualitative improvement in the physical, mental and moral faculties, he gives much practical advice which must needs prove of much service to the physician called upon to render qualified aid to the aged. Out of considerations like these naturally arise new conditions which, singly or combined, in no small measure effect a further improvement in the rate of mortality, with a consequent de- cline in the death rate in adult life, which as yet has been only very slight in the experience of modern countries, while at some age periods, in fact, the rate is higher now than in former years. * The solution of the problem depends largely upon the clear recognition of the important truth that the causes of old age and premature death in adult life lie probably as largely without the body as within it and that, in fact, no definite limit can safely be placed upon human longevity in the present inadequate state of our knowledge regarding the whole problem of life, its nature, maintenance and continuity, f The Assumed Law of Mortality No one can forecast the future consequences of these scientifically tenable and far-reaching conclusions. The chances of death are not *For an extended discussion of the close association of cancer with the degenerative periods of life and of the general subject of the nature of old age and senility, see a paper by Hastings Gilford, F. R. C.S., in the British Medical Journal, for December 27, 1913. tin the May 29,1914, issue of the London Times (weekly edition) a statement is quoted by Prof. Metehnikoff with regard to the ultimate result of the campaign against preventable diseases, in which it is said that "Rid of these terrible scourges, humanity will be able to concentrate upon its intellectual development." "Mortality among civilized peoples has certainly diminished," he said. "People live longer and though the strain of life may be said to be more intense, improved communication allows them to live away from the great centres and in the purer air of the country." With reference to Prof. MetchnikofFs views on the ultimate effect of the lengthening of human life, the correspondent states that "His theories are admirably exemplified in his own power to work, which is one of the reasons why he has not given more to the world in the form of scientific exposition; he considers he can still be of use to the present generation in directing their studies. This ambition, wholly justified by the fact that his laboratory assistants continually consult him in their work, is proof of his splendid vitality. In his cosmos, as revealed in "The Nature of Man," the septuagenarian and those of more advanced age have still work to do. Political conditions in Russia would have improved, he thinks, if older heads had directed the reform movement. The rashness of young men has been disastrous to the country, because it has provoked reaction." 27 fixed, nor is there a true law of mortality in the sense of natural law as distinct from scientific law, which, in the words of Karl Pearson, is essentially a product of the human mind and has no meaning apart from man. In the sense of this definition there is a law of mortality which is merely a descriptive expression of as wide a range as possible of the sequences of our sense impressions, describing but not explaining the orderly manner in which human life terminates in the mass of man- kind, with a due regard to age and sex. Numerous efforts have been made to establish with scientific precision the natural and mathematical laws concerning population vitality and mortality, but no effort of this kind has been successful, chiefly for the reason that so large a proportion of the causes of death among all mankind are preventable or post- ponable, as the case may be. Corbaux, in 1835, made an elaborate attempt to establish the natural law according to which what he called "the waste of human life" takes place, but he properly observed that to admit as universal "any law whatsoever of mortality, under the present constitution of society, would be an error." He nevertheless concluded that, "on the other hand, a very extraordinary notion, that the law of mortality had undergone a material alteration within a century seems to have gained credit with many who fail to reflect upon the im- mutable character of all Nature's laws, without exception." This con- clusion by Corbaux is absolutely contrary to the facts of human experi- ence, for, as fully brought out by the present discussion, the rate of mortality is not only subject to a wide range of variation, but a permanent reduction in the rate may result from sanitary and other im- provements which more or less condition the termination of life. Sussmilch and some other writers aside from Corbaux have erroneously assumed an immutable law of mortality, but the facts of human experi- ence for half a thousand years, at least, sustain the conclusion that the birth rate, the death rate, and human multiplication are largely matters of human control.* Heredity and the Death Rate How far a tendency to longevity is inherited can not be fully discussed on this occasion. It is no doubt true that "the organism and its inheri- *The improvement in longevity, actuarially considered, for the nineteenth century was discussed in a number of important papers on the occasion of the Fourth International Actuarial Congress, held in New York in 1903. Of special interest are the papers on the Improved Longevity in England and Wales, by Samuel G. Warner, and the Improvement in Longevity in the United States during the Nineteenth Century, by John K. Gore. The subject was further considered on the occasion of the Seventh International Congress of Actuaries, held at Amsterdam, in 1912, including observations on the Decline in the Mortality of Assured Persons since 1800. Of special interest are the reports on the Experience of the Gotha Life Insurance Company, 1829-1895; the Ex- perience of the Leipzig Insurance Company, 1830-1899; the Experience of the State Insurance Institutions »t Denmark during the Nineteenth Century, and the Changes in the Rates of Mortality among Assured Lives during the Past Century, by Messrs. Burn and Sharman of the Prudential Assurance Company, London. Men- tion also requires to be made of an extremely interesting paper on a comparison between the Mortality Experi- ence of the Equitable Life Assurance Society at the Beginning and the End of the Nineteenth Century, by Henry William Manly. 28 tance are, to begin with, one and the same," but the external factors which condition longevity are of much greater importance, at least through all the early years of life, than the internal disease-resisting and possibly inherited tendencies of the organism. Unquestionably there is much in inherited individual or race traits, but there are also innumerable ex- ceptions which have yet to be explained by scientific theories and which will continue to perplex and confuse the wisest of mankind. Only a scientific mind of a high order could even attempt to unravel the interrelations of the apparent law of human mortality, or the chances of death to the biological phenomena of a selective death rate, and the perhaps equally important problem of reproductive selection. The selective death rate, with regard to which as yet very little is actually known but much assumed, represents the inherited longevity, but be- comes operative as a general principle only during the adult portion of life. Pearson has briefly considered this phase of the subject in his papers on "Data for the Problem of Evolution in Man," with particular reference to the principle laid down by Wallace and Weissmann that the duration of life in an organism is fundamentally determined by natural selection. According to Pearson also, the selective death rate represents a consider- able portion of the total death rate, and, in his words, "having demon- strated that the duration of life is really inherited, it has also been demonstrated that natural selection is very sensibly effective among mankind." He proves, or at least attempts to prove, for his data are hardly sufficient for entirely safe assumptions, that there is certainly a well-established correlation between the ages at death of fathers and sons, for he adds, "the heredity is not absolute, since there is a sensible diver- gence from the law of inheritance, in that the death rate is only in part selective." There is an extensive literature on inherited diseases, much of which fails to meet the test of impartial and strictly qualified scientific criticism. Pearson himself, in his interesting address on "Social Prob- lems: Their Treatment, Past, Present and Future," has emphasized the serious possibilities of far-reaching errors in crude methods of statistical analysis, but, speaking broadly, the liability to grave mistakes *See in this connection a paper on "The Supposed Inferiority of First and Second Born Members of Families," and statistical fallacies inherent in discussions of this kind, by T. B. Macaulay, Montreal, Can. The Pathology of the Order of Birth, with Special Reference to Tuberculosis, has been discussed by W. C. Rivers, briefly reviewed in the Medical Record, New York, for October 28, 1911. The Influence of Parental Age on certain characters in offspring has been considered on the basis of statistical investigations in Middlesborough by Robert G. Ewart, M. D., briefly reviewed in the Lancet, of October 26, 1912, and a further review of the same discussion is con- tained in the British Medical Journal, of December 21, 1912. For an admirable discussion of the subject of the Inheritance of Fecundity, by Dr. Raymond Pearl, see Popu- lar Science Monthly, for October, 1912, the paper having originally been read at the First International Eugenics Congress, London, 1912. The Comparative Fecundity of Women of Native and Foreign Parentage in the United States has been discussed in a paper contributed by Joseph A. Hill, published in the Quarterly Publica- tion of the American Statistical Association, for December, 1913. See also in this connection a monograph by Elderton, Karl Pearson, etc., on the Correlation of Fertility with Social Value, published by Dulau & Co., London, 1913, and an extremely valuable work by Dr. Max Hirsch on the prevention of conception in its rela- tion to the declining birth rate, published under the title "Fruchtabtreibung und Priiventivverkehr im Zusam- menhang mit dem Geburtenriickgang," Wiirzburg, 1914. 29 is even greater in mathematical-statistical researches, resting, as is frequently the case, upon an insufficient numerical basis of facts. Centenarians A brief reference must here be made to the subject of cente- narians and the chances of extreme old age, which are apparently in- creasing in many civilized countries for which the data are available. It is well known that annuitants are more likely to attain to old age than persons badly provided for with the necessaries of life, and it therefore follows that substantial improvements in the social and economic con- dition of the population must necessarily tend towards the same result. The economic importance of this question is quite considerable in view of the increasing extent to which the pecuniary needs of the aged are provided for now by state, corporate or private pensions, best indicated in the case of England and Wales, where in 1912 there were 642,524 old-age pensioners, equivalent to 59.9 per cent, of the popu- lation ages seventy and over. In the United States in 1910 the pro- portion of population ages sixty -five and over was 4.4 per cent., against 4.1 for the year 1900. The actual number of aged persons in this country in 1910 was 3,950,000. If half of these were provided for with non-contributory old-age pensions of only five dollars a week, the re- sulting cost to the nation would be now about $520,000,000 per annum.* As an illustration of the extent to which extreme old age is at present attained in this country, the census returns may be quoted, though it is practically certain that they are probably erroneous, at least in the age returns for persons beyond the century mark. In 1910 there were 7,391 persons enumerated as of the age period ninety-five to ninety-nine, and 3,555 persons were returned as being over one hundred years old. A serious question of doubt naturally arises as regards the accuracy of age returns for centenarians, since thorough research in individual cases, as a rule, fails to provide the required documentary evidence of fact. In a monograph on centenarians, by T. E. Young, published in 1899, which constitutes one of the few thoroughly scientific contributions to the subject, a discussion is included of the dependence of the duration of life upon external physical conditions, which quite fully sustains the earlier conclusions of the present discussion that the human death rate is largely the resultant of external conditions, most of which are subject to human control. Young quotes the definition of life by Bichat, physiologist, as "the sum of the functions by which death is resisted," *I have quite fully discussed the subject of Old Age Pensions in an address on the Problem of Poverty and Pensions in Old Age, National Conference of Charities and Corrections, 1908; State Pensions and Annuities in Old Age, an address before the Massachusetts Reform Club, published in the Quarterly Publication of the Ameri- can Statistical Association, March, 1909; and an address on the American Public Pension System and Civil Service Retirement Plans, Seventh International Congress of Actuaries, Amsterdam, 1912. See also in this connection the exceptionally interesting and valuable report on the Police Pension Fund of the City of New York, published by the Bureau of Municipal Research, 1914. 30 and all the foregoing considerations make it clear that there is appar- ently a gradual increase in disease resistance on the part of an increasing number of mankind, partly, no doubt, in consequence of the economic improvement in the condition of the people, provided for with better food, housing, medical attendance, etc. Life Tables and the Average Age at Death The improvement in human longevity resulting from a decline in the death rate finds its most scientific expression in the so-called mean after-lifetime, or the expectation of life. There are no life tables for the United States as a whole, nor for any particular section thereof, for very recent years which afford the means of comparing accurately the changes which have taken place in the expectation of life during a considerable period of years.* The two Massachusetts life tables which have been constructed for the '50s and '90s, it is true, indicate a considerable degree of progress, but for reasons which need not be discussed here, they are not strictly applicable to the country as a whole. For the present pur- pose, therefore, the discussion is limited to the three English life tables for healthy districts, which have been constructed with extreme care for three periods of time. According to these tables the expectation of life at birth for males living in healthy districts increased from 48.56 years during the period 1849-53 to 52.87 years during 1891-1900. The corre- sponding improvement in the longevity of women was from 49.45 years to 55.71 years. These differences, apparently slight, are of very con- siderable economic importance when applied to the whole population. Stated in another form, according to the English healthy-district life tables, out of one million males born during the period 1849-53, the number surviving to age sixty was 485,014, whereas for the period 1891-1900, the number thus surviving was 551,973. According to the vital statistics of the United States for 1910, the average age at death attained by those dying during the year was 38.7 years, which compares with an average of 35.2 years for 1900. The average age at death, of course, must not be confused with the expectation of life, which is arrived at by fundamentally different mathematical proc- esses. In the absence of life tables for the United States, however, this rather crude indication of an improvement in American longevity is the only statistical evidence available which can be relied upon as approximately accurate. The improvement has been chiefly the result *A life table for the United States has been in course of preparation by the Division of Vital Statistics of the Bureau of the Census for several years, but work on the same has of late been discontinued. There would appear to be no technical reasons why at least an approximate life table for the United States should not be constructed with the same degree of accuracy as is obtained for life tables of many other countries of the world. The life tables published for certain American states and cities by the Census Office in former years are useful, but out of date. The most recent life table, for the City of New York, has not been pub- lished in sufficient detail to make the same as practically useful as the corresponding life tables of London and certain other large English cities. 31 of the diminishing mortality from the acute infectious diseases of infancy, typhoid fever, malaria, and tuberculosis.* The economic value of such a reduction must be very considerable, but it is far from being the equiva- lent of a real improvement obtainable in consequence of a material reduction in the death rate of the adult population, by means of which the more valuable lives as representing accumulated human skill and experience would be substantially prolonged. The Mortality from Cancer Foremost among the causes of death in adult life which require present consideration is cancer, or the group of malignant diseases con- veniently combined under that term. Cancer is unquestionably on the increase in this and other civilized countries, and the aggregate mortal- ity therefrom in the United States approximates seventy -five thou- sand deaths per annum, and throughout the civilized world over half a million. There are the strongest possible reasons for believing that by means of improved and early diagnosis, operative technique and medi- cal treatment, a material reduction in the cancer death rate can be brought about within a comparatively short period of years. This conclusion ap- plies primarily to the external cancers, chiefly of the skin and breast, but also to some of the internal cancers, particularly of the uterus. In propor- tion, of course, as these efforts, wjiether medical or surgical, are success- ful, a further decline in the death rate must follow, with much greater economic consequences than would result from a corresponding dimi- nution of the mortality of infancy or early youth, f Accidents, Homicides and Suicides Last, but not least, among the preventable causes of death a brief mention requires to be made of accidents, homicides and suicides. In the United States there are approximately eighty thousand deaths from accidents annually, of which about twenty -five thousand are accidents in industry. In addition thereto there are about fifteen thousand suicides and over six thousand homicides per annum, of which it is safe to say a considerable proportion could be prevented by thoroughly effective methods of moral and social reform. There is nothing more lamentable than the growing disregard for the sanctity of human life, as forcibly illustrated in the truly astonishing number of suicides and murders often for most trivial causes. The nation-wide campaign for safety and sanitation is one of the encouraging evidences of a higher *For a full discussion of the decline in the death rate from tuberculosis, see my address on the Reduction in the Tuberculosis Death Rate, ninth annual meeting of the National Association for the Study and Prevention of Tuberculosis, Washington, 1913, also my discussion of the Care of Tuberculous Wage-earners in Germany, Bulletin No. 101, U. S. Bureau of Labor, 1912. tSee in this connection my address on the Menace of Cancer, thirty-eighth annual meeting of the American Gynecological Society, Washington, 1912. 32 humanitarianism, resulting from more rational conceptions of social and political justice, best illustrated in the comparatively rapid progress of workmen's compensation legislation, which, in course of time, is bound to include compensation for industrial diseases. The problem, however, is not fully met by compensation for injuries and diseases, but. more effectively by the removal of the causes and conditions responsible for fatal accidents and injuries known to be preventable and needless. A measurable reduction in the number of accidents must necessarily affect the general death rate and contribute substan- tially towards a further decline than has thus far resulted from the efforts, which have in the main been limited to preventable diseases. The Decline in the Birth Rate The interrelation of a declining death rate to a declining birth rate and population growth is so self-evident as not to require extended dis- cussion. The evidence is quite conclusive that the birth rate of civilized countries is declining, and particularly so among the more prosperous and well-to-do elements of the population. The investigations of Karl Pearson and his associates into the problem of fertility and its relation to social worth are but indications of more elaborate methods of inquiry, which are bound to disclose facts and conditions as yet very imperfectly understood, if at all. The astonishing evidence presented to the Royal Commission on the decline in the birth rate in New South Wales finds its parallel in nearly every specialized study of the subject. It is en- couraging to find, therefore, that the fall in the birth rate was recently discussed at a conference held at Edinburgh under the auspices of the Scottish Council of Public Morals, at which the causes for the fall in the birth rate were pointed out to be the high standard of living, the love of pleasure, the consequent shirking of parental responsibility, and the higher education of women and their wider entrance into industrial and professional pursuits. It was therefore suggested that the subject should be made one of private rather than of government inquiry, so that the underlying facts and conditions might be ascertained with less difficulty, although the experience of the Royal Commission of New South Wales abundantly proved the perfect willingness of important witnesses to come forward with the truth. In an address of mine on the decline in the birth rate, published in the North American Review, for May, 1909, and a brief statistical study on the maternity statistics of Rhode Island, contributed to the proceedings of the First International Eugenics Congress, I have quite fully enlarged upon the details of these phases of the present discussion, of which, however, a brief mention could not well be avoided. The birth rate of the Australian Common- 33 wealth between 1886 and 1911 decreased from 35.4 to 27.2; of Austria, from 38.3 to 31.4; of England and Wales, from 32.8 to 24.4; of France, from 23.9 to 18.7; of the German Empire, from 37.0 to 28.6; of Hungary, from 45.6 to 35.0, and of the Netherlands, from 34.6 to 27.8 per one thousand of population. There are no corresponding statistics of births for the United States, and for the few New England States for which they are available the results are hardly applicable to the country as a whole.* Possible Future Population Growth Passing from these biological and general considerations to the economic significance of a declining death rate, it is necessary to con- sider the statement made at the outset of the numerical relation of such a decline to the world's growth in population. It was shown that the annual increase is approximately 13,260,000, which is a conservative estimate and quite likely an understatement of the facts. Further advances in sanitation, the practice of medicine, safety in industry, etc., will tend to bring about a still further reduction in the death rate, equivalent to a higher general rate of natural increase than prevails at the present time. As a single concrete illustration, it may be pointed out that while for all India the natural increase in 1910 was 6.3 per one thousand of population, the rate was as high as 11.25 in the north- west frontier provinces and 10.5 in the central provinces. It is therefore self-evident that there are vast possibilities for an augmentation in the natural rate of increase in the world's population, and there are the strongest possible reasons for believing that, largely because of a declin- ing death rate, the future rate of human increase will be greater than the rates prevailing in the recent past. The economic consequences of such an augmentation of the world's population will unquestionably be quite serious, particularly with regard to the available food supply provided chiefly through the employment of productive human energy upon the land. Decline in Rural Population The present indications in this respect, however, are not alarming, for apparently the area devoted to the principal food crops is increasing even faster than the corresponding growth in population. But the data are far from satisfactory. In practically all the civilized countries the tendency of the population is largely toward the cities, and the employ- ment of productive energy in manufacturing industries, governmental or corporated administration, the professions, and the modern methods *The national and international significance of the declining birth rate has been discussed with admirable brevity by Dr. Arthur Newsholme in the new Tracts for the Times, issued by the National Council for Public Morals, London, 1911. 34 and requirements of distribution. The recent rise in the price of agricultural products is largely to be attributed to this condition. As previously pointed out, the urban population in the United States during the last decade has increased 35 per cent., whereas the corresponding increase in the rural population was only 11 per cent. In many of the most important agricultural sections of the country there has been but a slight increase in the rural population or an actual decline. Such an actual decrease in rural population occurred, for illustration, in such typically agricultural states as New Hampshire (5.4 per cent.), Vermont (4.2 per cent.), Ohio (1.3 per cent.), Indiana (5.1 per cent.), Iowa (7.2 per cent.), Missouri (3.5 per cent.). In the State of New York fifteen counties decreased in population during the past decade, including many in which the agricultural opportunities are distinctly encouraging; in Michigan there was a decrease in population in twenty-six counties ; and a corresponding decline occurred in twenty counties of Wisconsin. The rural population of Michigan increased only 2.0 per cent. ; of Wisconsin, 5.7 per cent.; and of Minnesota, 7.7 per cent. The urban popu- lation in these three states increased 37.3 per cent, in Michigan, 23.8 per cent, in Wisconsin, and 38.6 per cent, in Minnesota. In con- trast to an apparent decline in the growth of agricultural interests there has been a decided increase in farm values, for while the improved acreage in farms increased for the United States during the last decade only 4.8 per cent., the value of farm lands increased 118 per cent., and the average value of farm land per acre increased from $15.57 in 1900 to $32.40 in 1910, or at the rate of 108 per cent.* Problem of Conservation of Natural Resources The corresponding increase in the cost of living during the last two decades affects practically all of the necessaries, including every essential item of the food supply. It would seem that the methods of general agriculture have not made anything like the progress which has been attained in the mechanical industries, although the results in the latter are of much less immediate importance to the consumers than the former. A constantly increasing urban population must tend to bring about a further increase in the price of agricultural products, unless in the future a much larger proportion of human energy is employed in the productive industries which minister to fundamental human wants. All that is summed up in the modern conception of the governmental duty of conservation of natural resources for the needs of future generations is primarily conditioned by the indisputable indications of a larger future rate of natural increase in the world's population than has *For additional details, see "Rural Health and Welfare," published by The Prudential Insurance Company of America, 1912, in connection with the New York Agricultural Exposition. 35 prevailed in the past. Foremost, it would seem, as a public problem, is the essential need of improved methods of agriculture, as best emphasized in the relatively low yield of agricultural products obtained in the United States, in comparison with foreign countries where the soils must long ago have been exhausted to a more considerable degree. The average yield of wheat per acre, for illustration, during the decade ending with 1912 was only 14.1 bushels for the United States, compared with 18.4 for Hungary, 19.8 for Austria, 20.4 for France, 30.1 for Germany, and 31.7 for the United Kingdom. The average yield of oats, which is a food product of considerable value, was 29.6 bushels per acre for the United States, against 29.8 for France, 30.8 for Hungary, 31.1 for Austria, 44.3 for the United Kingdom, and 51.9 for Germany. A corresponding condition is shown by the comparative statistics of the average yield of rye, which was 15.8 bushels for the United States, 18.3 for Hungary, 20.6 for Austria, 27.0 for Germany, and 28.4 for Ireland. It seems, therefore, an entirely sound conclusion that there remain vast oppor- tunities for increased agricultural production without any necessary considerable enlargement of the area devoted to the raising of cereal crops, but as a brief contribution to the practical side of this question, the following international crop statistics are given as derived from the Yearbook of Agriculture for 1912. International Crop Statistics The area of the world under wheat in 1908 was 242,472,000 acres, which by 1912 had increased to 265,736,000 acres. The increase in area, therefore, was equivalent to 9.6 per cent., which compares with 3.9 per cent, of corresponding increase in population. The world's wheat crop in 1895 was 2,593,000,000 bushels, which by 1912 had increased to 3,759,- 000,000 bushels. The increase in the wheat crop was, therefore, equiva- lent to 45.0 per cent., which compares with an increase of 12.6 per cent, in the world's population during the intervening period of time. The world's area under corn in 1908 was 160,707,000 acres, which by 1912 had increased to 168,154,000 acres, or 4.6 per cent. The corre- sponding increase in population during the same period was 3.9 per cent. The corn crop of the world increased from 2,835,000,000 bushels in 1895 to 4,055,000,000 bushels in 1912. The increase in corn pro- duction during this period was, therefore, equivalent to 43.0 per cent., which compares with a corresponding increase of 12.6 per cent, in the world's population. The area of the world under oats in 1908 was 128,897,000 acres, which by 1912 had increased to 142,935,000 acres. The increase in area, therefore, was equivalent to 10.9 per cent., which compares with a cor- 36 responding increase of 3.9 per cent, in population. The world's oat crop in 1895 was 3,008,000,000 bushels, which by 1912 had increased to 4,585,000,000, an increase equivalent to 52.4 per cent., as compared with a corresponding increase of 12.6 per cent, in the world's population. The world's area under barley, which is a food crop of no small im- portance, increased from 65,663,000 acres in 1908 to 67,819,000 acres in 1912, an increase equivalent to 3.3 per cent., which compares with a corresponding increase in the world's population of 3.9 per cent. The world's barley crop increased from 915,504,000 bushels in 1895 to 1,458,- 000,000 bushels in 1912. There was, therefore, a relative increase in barley production of 59.2 per cent., which compares with a correspond- ing increase of 12.6 per cent, in the world's population during the inter- vening period of time. The world's area under rye, which is also a crop of considerable im- portance as a source of food supply, increased from 106,121,000 acres in 1908 to 108,292,000 acres in 1912, an increase equivalent to 2.1 per cent., corresponding to an increase of 3.9 per cent, in the population of the world during the same period of years. The world's rye crop increased from 1,468,000,000 bushels in 1895 to 1,901,000,000 bushels in 1912, an increase equivalent to 29.5 per cent., which compares with a correspond- ing increase in population of 12.6 per cent. The world's rice crop increased from 91,000,000,000 pounds in 1900 to 174,000,000,000 pounds in 1911. The increase in production during this period was equivalent to 91.2 per cent., which compares with a corre- sponding increase of 8.8 per cent, in the population of the world. The available evidence, therefore, is distinctly encouraging, some exceptions to this view notwithstanding, that a considerable further in- crease in the world's population is entirely consistent with at least an equal rate of growth in the production of the cereals required for the world's food supply. The same conclusion, though to a lesser degree, applies to the products of animal industry, which, however, it is not possible to discuss on this occasion. Evidence of Augmented Population Growth The progress of the human race as an economic problem is, therefore, apparently not as yet seriously affected by the decline in the general death rate, with a resulting proportionately larger increase in population. The problems of the immediate future are social, moral and political, as partly emphasized in the following table, exhibiting the popula- tion growth of Europe and the United States combined, since the com- mencement of the nineteenth century and cast forward to the year 1960: 37 Population of Europe and the United States Annual Year Europe United States Total Increase per 1,000 1800 187,693,000 5,308,000 193,001,000 1810 198,388,000 7,240,000 205,628,000 6.3 1820 212,768,000 9,638,000 222,406,000 7.8 1830 233,962,000 12,866,000 246,828,000 10.4 1840 250,972,000 17,069,000 268,041,000 8.2 1850 266,228,000 23,192,000 289,420,000 7.7 1860 282,893,000 31,443,000 314,336,000 8.3 1870 305,399,000 38,558,000 343,957,000 9.0 1880 331,745,000 50,189,000 381,934,000 10.5 1890 362,902,000 62,980,000 425,882,000 10.9 1900 400,577,000 76,303,000 476,880,000 11.3 1910 449,520,000 91,972,000 541,492,000 12.7 1920* 506,151,000 109,999,000 616,150,000 13.0 1930* 571,081,000 130,019,000 701,100,000 13.0 1940* 645,901,000 151,862,000 797,763,000 13.0 1950* 732,506,000 175,248,000 907,754,000 13.0 1960* 833,127,000 199,783,000 1,032,910,000 13.0 *Based on an assumed stationary annual increase of 13.0 per one thousand and the theory that in the future a larger share of European emigration will go to countries other than the United States. During the period of recorded population growth for Europe and the United States there has been a rise in the rate of natural increase from 6.3 per one thousand during the decade 1800-10 to 12.7 per one thousand during the decade ending with 1910; and the actual population of Europe and the United States combined has during this period in- creased from not quite two hundred million to over five hundred and forty million. Political Problems of Population Growth Foremost among the political problems resulting from such an in- crease in population, with a corresponding increase in density, are the increasing expenditures on account of government, best illustrated in the simple statement of the fact that in 1912 the approximate revenue of civilized countries was $11,574,000,000, and the corresponding ex- penditures, $11,687,000,000. Of the expenditures, $1,686,000,000 was on account of interest and other annual charges upon an accumulated debt of $41,737,000,000. In practically every civilized country these burdens of fixed charges on account of debts, largely of a non-productive character, are increasing; but particularly so in the case of local govern- ments, chiefly large cities, which are not included in the foregoing state- 38 o 22 i o o go <2 ' SB < c CO o '(_ a> £ < Q. O 1_ Ld C o SB D a. o Q_ s- o -C $ o i_ CD ( ( 1 — oooooooooooo oooooooooooo oooooooooooo z o H < _J a. o a. ooopi-oim/)ioonn cOKnouiffluiniii-jom r%C0Cv/vTCOC\JCvjCD0 r )-3-CD«4' c ( 0D-0)^(O0)rsC0Ol(DO01 en — o*JLnr\(Dc\jLna)>3-oco oooooooooooo COC0CO0DCDCOCDCOCD00CT>