Digitized by the Internet Archive in 2011 with funding from Open Knowledge Commons http://www.archive.org/details/inauguraldissertOOyoul A N INAUGURAL DISSERTATION O N RESPIRATION: BEING An APPLICATION of the PRINCIPLES of the NEW CHEMISTRY to that FUNCTION. SUBMITTED TO THE PUBLIC EXAMINATION OF THE FACULTY OF PHYSIC, UNDER THE AUTHORITY OF THE TRUSTEES OF COLUMBIA COLLEGE IN THE STATE OF NEW-YORK: WILLIAM SAMUEL JOHNSON, LL.D. Prtfidentj FOR THE DEGREE OF DOCTOR OF P H T S I C-, ON THE THIRTIETH DAY OF APRIL, 1 7^3. * By JOSEPH YOUL*E, Citizen of the State of New- York. Hominem autem Jova Deus quum ex terrze pulvere formavifiet, et in ejus nares fpiritum vitalem infpiravifiet, ex quo eflet aninians homo effec- tus. Gen. N E W- Y O R K: Printed by T. and J. Swords, Printers to the Faculty of Phyfic of Columbia College, No. 27, William-Street. — 1793.— 5f^Ce'/ m iff Imprimatur. William Pitt Smith, C15 T O JOSEPH YOUNG, PHYSICIAN; WILLIAM PITT SMITH, PROFESSOR OF MATERIA MEDICA IN COLUMBIA COLLEGE: INDEBTED to you for the foundation of the fmall Medical Superftruclure, which, through Providence, I have been enabled to ereEl— having piloted my little Bark to the Haven of her Defire\ if any thing in the following pages fhall be found worthy of attention, Permit them to be dedicated to you, With every mark of esteem and respect, By your Friend and Pupil, The AUTHOR. T SAMUEL BARD, M. D, PROFESSOR OF CLINICAL MEDICINE, AND DEAN OF THE MEDICAL FACULTY: D I S S E R T A T I O N Is infcribed, As a mark of refpecfh Application of the Principles OF THE New Chemistry to RespipvAticw* JL O live and to breathe are fy nonymous expref- fions. Refpiration is, therefore, a function of the animal body, with propriety termed vital It would be a pleafing, as well as profitable undertaking, to trace the progrefs of the human mind in theinverti- gation of this phenomenon of being. Notwith- ftanding it has engaged the attention of Phyficians and Philofophers of every age, nothing has been written on the fubjecl, till within a few years, which is worthy of attention. The rapid improvements in the fcience of Aerology , of which Doctor Priestly is the difcoverer, have enabled the modems to view the fubjecl: in a more juft manner than the ancients could pofTibly have done. Air is necefTary to the exigence of all organized beings. We find none exifting where they are not admitted to its contact; even plants, as well as ani- mals, are found by experiment to die in vacuo. Nature ( 6 ) Nature has taken great pains to provide animals, even of the moft infignificant kind, with organs for bringing their blood fufficiently in contact with the fluid in which they live. This is inftanced in a manner remarkably curious in infecls, in their diffe- rent modes of exigence. From numerous obferva- tions it appears, that air is more effential to animal life than aliment. It forms a great part of the food of plants, and probably alfo of animals -, but each of thofe claffes of being requires it of different kinds : that which is the moft falubrious to plants being noxious to animals ; and that which is emitted as excrementitious by the former, moft falutary to the latter. Thus, by an unequalled defign, are thofe two kingdoms made to labour for each other, and tho. balance between the components of our atmof- phere preferved. — The death of animals, by fub-. xnerfion, ftrangulation, and fuffocation, is produced by a privation of this all-vivifying fluid. We may be eafily convinced of its effentiality to life, by vo- luntarily fufpending refpiration a few moments. The vail serial ocean in which we continually move, although apparently a limple fluid, is in fad a very heterogeneous mafs. It is compofed of the various fubftances which are capable of being vola- tilized at the temperature at which it exifts, and which it can by its folvent power fufpend, Monf. Lavoisier has proved, fynthetically and analytically, that it is compofed of oxigenous gas, and mepbetic airs, m the proportions of 27 and 73 to the 100 parts. This ( 7 ) This mephetis confifts chiefly of azotic, although it contains a final] portion of carbonic and hydroge- nous gafes* That carbonic gas enters as an ingredient in the compofition of our atmofphere,. has been proved to a demonftration. It is fufficient for this purpofe to mention, that lime water expofed to the air is ren- dered turbid, the lime becoming precipitated > and that cauftic alkalies (pure alkalies) are carbonated^ or rendered eitervefcent. . That hydrogenous gas exifis in the atmofphere, has not fo generally been allowed : but whoever will confider what a vaft quantity of this gas is exhaled from marines, mines, putrifying animal and ve- getable fubftances, will" not have a doubt remaining on this head. The airs, then, w T hich compofe our atmofphere, are, the ovigenous ', azotic , carbonic, and hydrogenous, j Now, * The oxigenous, azotic, carbonic, and hydrogenous gafes of the French Chemifts, are fynonymous with the dephlcgifticated, phlogifticated, fixed, and inflammable airs of Priestly. •f The mechanical properties of the atmofphere have, till very lately, entirely attracted the notice of Philcfophers. The attention of men of the greater!, eminence is now turned towards Its compcfition. The propor- tions of the ingredients in this fluid muft vary according to a variety of circumflances and fituations. The analyiis of the accurate L.^ voisier, already mentioned, is about the medium, and may be moft relied upon, as his abilities and apparatus enable him to do julVice to the inquiry. The proportion of carbonic gas is generally eftimatrd at an hundreth part, that of the hydrogenous is not afcertained. Probably neitlher are eflVntial to the compofition of atmofpheric air, as the azotic gas, is fufficknt to qua- lify the acYum of the oxi^enuus. C 8. ) Now, as animals cannot live without air, it muft be fame one of thefe components of the atmofphere in particular, which fupports their exigence, or the whole collectively. Azotic gas (as its name fignifies) is noxious to animal life. " It cannot be breathed by animals, neither will it admit of the combuftion of inflamma- ble bodies, nor of the calcination of metals.'* If common air be infpired into the lungs, and again ex- pired into a receiver, the volume becomes diminifh- ed, while the azotic gas remains the fame both in quantity and quality. It is, therefore, unfit for the plirpofts of refpiration. Hereafter it will appear, that refpiration is not merely a paflive function -, that it is not confined to the mere reception and cmiflion of air. The unrefpirability of carbonic gas was long fince fhewn by Van Helmont, and has fince been proved by Hales, Priestly, and others. It is manifefted by the experiments which have been made on dogs in the grotto del cano y and by accidents which happen in breweries, cellars, and places where the procefs of fermentation is going on. It is this gas which produces the fatal effects that follow from the com- buftion of charcoal in confined places. The expe- riments which have been made on animals in the air exhaling from mineral waters, prove the fame fact. It is further corroborated by the actual experiments of the Abbe Nollet, and the intrepid Pilatre de Rosier* ( 9 ) Rosier, who breathed it at the hazard of life: De Rosier had not taken more than two or three infpi- rations, before he was feized with all the fyrnptoms of apoplexy. Bergman obferves, that it kills ani- mals inftantaneoufly, and that the hearts of animals fo deftroyed are entirely deprived of their irritability. Hydrogenous gas is likewife incapable of fupport- ing refpiration. " Birds, placed fuccerlively in a vefTel rilled with this air, died without producing the fmalleft perceptible change in it." M. Chaptal fays, that he refpired it himfelf, and found that the fame air might be taken into the lungs feveral times without danger j and that it was not in the leaft vi- tiated or diminifhed after the experiment. De Rosier likewife infpired it feveral times with impu- nity. From thefe facts it appears that hydrogenous gas is incapable of being decompounded in the lungs : It is then merely a pailive fubftance in refpi- ration, producing death by a negation of fome other principle which can fupport this procefs.* Having afcertained that neither azotic* carbonic* nor hydrogenous gas can fupport refpiration, it there- fore follows, that the ovigenous is the only one fit for B this * From the experiments of feveral eminent perfons on this gas, it would appear, that it exerts a pofitive operation in the lungs, and that it is in itfelf deleterious. The Abbe Font an a found extreme difficulty in tak» ing three infpirations. of it. Thefe apparent contradictions will reconcile themfelves when we confider the power which this gas poffelfes of difiblving charcoal, fulphur, phofphorus, and federal of the metals.— On? pofuive experiment, like thofe mentioned in the text, ought to have more weight than an hundred negative onc^ ( If ) this purpofe \ for the exiflence of any other in oUf atmofphere is not afcertained. This gas, like every other, is a compound fub- ftance, It is formed of a radicle or bafe, called oxi- gene, held in folution by caloric (heat, fire, igneous fluid, matter of heat) to the point of faturation, which conftitutes its principle of elafticity. From the numerous experiments which have been made, it appears that ovigenous gas is capable of fupporting refpiration only a certain time ; and that air is refpirable in proportion to the quantity of this gas contained in it. Count Morozzo placed ten fparrows fucceffively under a glafs filled with oxige- nous gas -, the firft died in five hours and twenty- three minutes, and the air became considerably dimi- niihed in quantity -, the fecond died in two hours and ten minutes, the third in lefs time, and fo on •, the duration of their exigence diminishing in proportion to the diminution and vitiation of the air. Others, that were placed in atmofpherical air, died much fooner than thofe in oxigenous gas ; the collective duration of the exiftence of three fparrows placed fuccefilvely in the latter, being three times greater than in the former ; correfponding with the propor- tion of oxigenous gas prefent. Chaptal fays, that air in which five fparrows had died, yielded only feventeen hundreths of vital air. — As we have ihewn, that none of the gafeous parts of the atmofphere are capable of fupporting refpiration except C ii ) except the oxigenous, it mufl be from a diminution of this that breathing becomes difficult in crouded aflemblies without free ventilation. The above cited experiments mew that air is di- minifhed by animal refpiration. The lofs in one hour, by the breathing of a man, is 3 60* cubic inches, which will contain, according to the experiments of Lavoisier, 130 grains of folid oxigene. Now, it is impoffible for this gas to be diminished in bulk, unlefs by cold or by preiTure, without decompofi- tion •> and in order that fuch decompofition may take place, it is neceiTary that fome fubftance ihould come in contact with it, for which its oxigene has a flronger attraction than it has for its caloric : Such a fubftance exifts in the lungs of animals, and ihall be pointed out in its proper place. As oxigenous gas is decompounded in the lungs, refpiration may be considered properly a fpecies of oxigenation. Accordingly, it is found that the fame changes take place in the air during calcination, comburtion, and fermentation, as in refpiration. Thefe procefTes require fimilar circumftances to favour them, and produce feveral phenomena com- mon to each. 1. Oxigenous gas is required. 2. Caloric is ^engaged. 3. Oxigene becomes fixed. 4. The * " M. De la Metherie has proved that 360 cubic inches of vital air are abforbed in an hour. My experiments have not fhewn fo great a lofs." Chaptal's Chemistry. The eftimate of the lofs of air in an hour by Kales, is the fame as that of la Mather ie. See his Staticks. ( * ) 4. Tk? augmentation of the weight of the products is equal to the weight of oxigenous gas employed. If refpiration is a fnecies of oxigenation or com- bnftion, why does not the difengaged caloric manifeft kidf in the form of light and flame r The reafon is readily afligned. — The procefs of oxigenation va- ries according to a variety of circumftances. In order that it mav go on in a rapid manner, it is ne- celiary that the iubitance to which the oxigene is at- tached mould have a ftrong attraction for it, and that it mould be in a temperature moft favourable to inch an attraction. It is likewife neceffary that it mould be concentrated, and not diiTufed through a mafs of incombuftible matter. There is but one of thofe favourable circumftances exiiiing in the lungs of animals : the fubftaiice bv which oxigene is at- J o traded there, has indeed a ftrong affinity for it, as mall be fhewn-, but it is diftufed through a fluid imiuiceptible of combuftion. The temperature of animal bodies is probably not the moft favourable to a rapid procefs. The difengaged caloric will, under tiiefe circumftances, consequently, be invifible, a Suf- ficient quantity not being; evolved in any given ipace of time to manifeft itfelf by the properties of flame and light, Moreover, as fbon as the caloric is let loofe in the lungs, it is communicated to the forma- tion of the vapour and carbonic acid gas which are continually exhaling; from the lung's.' As * Whether :he v:; :-.;.• exh;i ; -r from "he lungs c* sn;n:ah :i formed thtre, by the ur.io:i of h^dro^ene pafMrif ircm tht oio-od with the oxigene ( 13 ) As the diminution of pktgem'us gas by animal re- fpiration is conftant and fucceiTive, wre mull: look for fome fiahftance in the lungs to which Irs bafe becomes attached. We know of no other matter there which has an attraction for cxigene fufncient to difengage it from its caloric, except the blood. In refpiration, therefore, the folid matter of oxigenous gas mult unite with this fluid. I am of opinion, that the oxi- gene of all the gas which is decompounded in the lungs paries into the blood, The from the air, or whether it be a fluid exhaled from venels already formed, is doubtful. The latter conjecture I think the moft probable ; for C an ? - tal fays, that when hydrogenous z::s is taken into the lungs of animals repeatedly, it does not alter either its quantity 01 ijaality: If hydrogene is comtantly exhaling from the bloed, ought no: the volumeof gas to have been augmeatei ? — I intend hereafter to determine this point, by placing animals in hydrogenous gas; if this aqueous fluid is then exhaled, itmuii fee fccre'ed from the blood. From a cat which I faw Profefihr Kemp place in a tolerably good vacuum, this halitus was exhaled, and mani felted itfelf by condenGng upon the fides of the receiver. — This fluid appears to poilef: the properties of '.vater, and muft therefore be formed in theexhalaat arteries; for I co not know of a drop of water, qjc a aqjja, in the ani- mal body. It is tranfpare.it, aimoit taftelef=, and evaporates by heat without coagulation or leaving any renduum. That carbonic acid gas extAs in greater quantity in the c'r exp ; re: from the lungs of animals than it did previous to hrfpiration, is proved by its rendering lime-water turbid, reddening the tincture of turnfole, and oy carbonating aikaiies when caufed to pafs through them. See Goouw^^'s inaug. diiTert. Priestly on air. Chaptal's Chem. — I am inclined to believe that the compound radicle of this gas is formed in the blood an3 not in the veiicles of the lungs; for, " according to the ■ of the Count Dt Mu.lt, and the obfervations of Fouoj-'ET," carbonic gas is constantly tilling off from the &in as well as the lungs. If M air be placed in contact with blood, it acquires the property of precip I lime-water." Whether the aqueous matter and carbonic acid are formed in the lungs cr not, they require a large quantity of ca;:;ic to convert them into the gafeous ftate ; and muft, no doubt, take up all tics caloric which .; extri- cated from the oxigenous gas in the lungs. ( U ) » ' The decomposition of fuch a quantity of oxigenous gas as takes place in refpiration, mull produce fonie corresponding change in the blood ; for experiments mew that this fubftance is a very general and power- ful agent in nature. It was long fince obferved by Lower, that the blood which flowed from the pul- monary veins was more florid than that which flowed from the artery. The fame fact has been fince taken notice of by Boerhaave, Haller, Cigna, Hew- son, Goodwyn, &c. &c. The blood, then, ac- quires a more florid appearance during its pafTage through the lungs. The caufe of this florid appearance has been made the fubject of the prize questions of many learned focieties. It was a long time attributed to nitre m the air, from the property which this fubftance has of communicating a red colour to blood out of the body. Boerhaave attributes it to texture •, Hal- ler to a mixture of oily and ferrugenous matter-, Hales to fulpbur\ Hewson to the efficacy of the fpleen and lymphatic glands. ! The fad: is, there have been as many conjectures reflecting the caufe of it, as there have authors written on the fubject. — It was left for the immortal Priestly to prove that the blood is indebted to what he calls depblogifticated air for its red colour.* He * The Doftor does not appear to have had an idea of the decompofkion of this gas in refpiration ; he fuppofes it moil fit for this purpofe of any of the airs, becaufe " it contains the leall phlogifton ;" and therefore, according to his idea, it is thebeft folvent or menftruum for that principle. Hence, fays he 5 refpiration is a l< phlogiltic procefs, the ufe of the lungs ( U ) He expofed a quantity of venal blood to common air* and found that by agitation it immediately be- came red ; but this was more eminently the cafe when oxigenous gas was ufed, and in a fhorter time.* Blood rendered florid in this manner, and blood ta- ken from an animal in this flate, were expofed to hydrogenous^ azotic and carbonic gafes \ the florid co- lour immediately difappeared, and the blood became black-, but upon expofure to oxigenous gas ^ it foon refumed its former appearance. Blood becomes red in proportion to the quantity of oxigenous gas con* tained in the air to which it is expofed. Hewson being to difcharge that phlogifton which had been taken into the fyftem with the aliment. 1 ' But as all the phaenomena which the Stahlians afcribe to the difengagement of phlogifton, are produced by combinations with oxi- gene, the experiments of Dr. P. are equally applicable to our purpofe, as if they were made upon the principles of the French Chemiftry. * Here it will be pertinent to remark, that as blood is rendered fluid fooner, and in a greater degree out of the body, by expofure to oxigenous gas than to atmofpherical air, it is certainly preferable, in cafes of fufpended animation, to inflate the lungs with it. Goodwyn found by ufing this inftead of common air that he could reftore animals fooner. This ga9 1 conceive, might be exhibited with great advantage in fevers of the typhoid kind, in dropfies, chlorofis, and other difeafes of debility. It is eafily procured, and is not a very dear remedy, as iaoo cubic inches can be obtained from one pound of nitre; and one pint from an ounce of minium. It is a grand defideratum to find a mode for obtaining it from water. Mint, lavender, and many other fragrant plants emit it in co- pious quantities, and might be placed in a fick room with great advantage ; they would be pleafing to the eve, grateful to the fmell, afford a ftimulus to the heart, and would abforb the unrefpirable part of the air. Chap- tal relates a cafe or two of its beneficial influence in pthifis pulmon. The breathing of this air " diffufes an agreeable warmth in the breaft, infpires cheerfulnefs, renders the patient happy: — In defperate cafes, it muft certainly be a precious remedy which can fpread flowers on the bor- ders of the tomb, and prepare us in the gentleft manner for the laft dread- ful effort of nature^ ( i6 ) Hev/son fays, that he injected air into a vein be- tween two ligatures, and found that the contained blood aflumed a more florid appearance. Beccaria expofed blood in vacuo •> it immediately became black. Priestly fays, that he repeated the expe- riment with the fame refult. The blood does not come in actual contact with the air in the lungs. That oxigenous gas can act through membranes apparently more denfe and im- permeable to air than the vehicles of the lungs, is evident from the following experiment of Doctor Priestly. A quantity of black blood was inclofed in a bladder, and expofed to the air •, when it was ex- amined, it exhibited the fame florid appearance as if it had been in actual contact with that fluid, the bladder appearing to be no obitruction to the procefs of floridation. It is a curious and interesting fact, that oxigenous gas can act on blood although it be covered with a flratum of ferum of the depth of two inches and an half: whereas the flighted covering of oil, faliva, or water, effectually prevents its action. As florid blood becomes black in vacuo, or when expofed to any of the unrefpirable gafes ; as this co- lour is restored by expofing it to oxigenous gas, which at the fame time becomes diminiihedj as blood is changed from black to red by oxigene out of the body, whether it be imparted to it from acids, neutral falts, oxigenous gas, or gafes containing a portion C -7 ) portion of this •, we may fafely conclude, that this principle is the immediate caufe of the fame change which the blood undergoes in the lungs. Priestly found by experiment, that if fuccemVe quantities of florid blood were placed in contact with a quantity of hydrogenous or azotic gafes, they be- came in a degree refpirable, and that nitrous air be- came leffened in bulk, at the fame time lofing its power of diminiming oxigenous gas. — Thefe phe- nomena, according to his theory, he afcribes to the abforption of phlogifton, by the blood, from the air: but any perfon verfed in the doctrines of the new chemistry will perceive, that they are owing to an emirTion of oxigenous gas, the bafe of which exifts in the blood. — This view of the fubject affords an eafy and fatisfactory anfwer to the unphilofophical queftion, whether air exifts in the blood in an elaftic form ? That the bafe of air exifts in the blood, and that it will eafily affume the gafeous ftate, is evinced from the experiments juft mentioned ; but if a vein be taken out of an animal with a ligature pafTed round each end, and it be placed under an exhaufted receiver, it will not fwell ; or if an artery or vein is punctured under water, not even the fmalleft bubble of air afcends. If air was to be injected into the veins of an animal, it would deftroy its life ; for we muft be convinced from the analogy of the blood vefTels to hydraulic tubes, that a fmall quantity of air in any of their fuperior flexures would effectually obftruct the circulation of the blood, C The ( i8 ) The blood of fijhes, of the feet us in utero, and of the chick in ovo 9 is red. Are not thefe objections to the theory which fuppofes that oxigene is the florid- ifying principle of blood ? That aquatic animals require air for the continu- ance of their exiftence as well as the terrene^ is ren- dered fufBciently evident from the well known fact, that fifh in the winter will rufh in crowds to holes which form or are formed in the ice— --an artifice fre- quently ufed for taking thofe animals. This por- tion is further corroborated by the following experi- ments. If a few fifties are placed in a veflel of water, and the air be effectually excluded, they will foon die. The fame takes place in vacuo, Thefe creatures feem to fufTer the fame inconve- nience from being crowded together in a fmall quan- titv of water, as men or other land animals do, when in confined places — the water probably not being fufficiently permeable to air to afford them neceffary iupplies. The experiments of Priestly throw great light en this part of our fubject, and furniin fufflcient data to prove, that oxigene is necefTary to the florid- ification of the blood of fifties. — He inclofed a num- ber of thefe animals in different veffels, containing water, with atmofpheres of nitrous, hydrogenous, azotic and carbonic gafes •, under which circumftances they died in a fhort time — in the carbonic gas they expired convulfed. He likewife placed two fmall fifhes ( i9 ) Mies in a pail of water : after they i had been in twenty-four hours, he found that the water had left its property of purifying air. In repeating the ex- periment with water which contained air of great purity, he found, after the fifh had died in it, that the air which it contained had not only become di- minifhed in quantity, but alfo that its quality was worfe than that in which a candle goes out. From thefe experiments it appears, that the gafes which are noxious to land animals, are unfit for the refpiration of fifties. From the diminution of the quantity of pure air in the water in which theft ani- mals had been, it is evident that they decompound oxigenous gas, and that, like terrene animals, they want conftant fupplies of frefh air. With refpect to the young of animals in utero, it- is now rendered fufficiently evident, that they are fupplied with arterial (oxigenated) blood by the umbi- lical vein. — -Whether the vefTels of the placenta have a power of taking up chiefly that part of the blood in which oxigene refides, or whether the arteries of the uterus tranfmit to the veins of the placenta chiefly that part, is. doubtful. Probably this will not appear neceflary when we advert to the well afcer- tained fact, that the blood of women during preg- nancy, and probably of other animals, manifeits a highly florid colour. — So wifely has Nature adapted means to ends, and upon fuch beautiful principles has (he conftituted the animal ceconomy, that the irritability irritability and tone communicated to the fyftem by a diftention of the uterus, fhould ad as a phyfical caufe in increaflng the power of oxigenating blood, in order that the foetus may be fupplied without in- juring the mother. f* The gen'ral Order fince the whole began, *! Is kept in Nature^ and is kept in Man." That oxygenation is necefTary to the blood of the chick in ovo, is manifefted from the fact, that if the communication between the membranous lining of an egg-fhell and the external air be cut off, it is inca- pable of being hatched, If I had time fufficient for the purpofe before me, I would try if it was poffible to hatch chickens in any of the unrefpirable airs, and whether oxigenous gas would facilitate that procefs* That their fhells are permeable to oxigenous gas, may be inferred from the putrefaction of eggs. When animal fubftances putrify, carbonic acid gas is exhaled -, and from analogy I conclude this to be the cafe with them. Oxigene is efTential to the for- mation of carbonic acid, and if it could not pene- trate their fhells, it is probable that they would never putrify. It is a notorious fact, that if they are coated with, or immerfed in any fubitance which will exclude the air from them, they may be pre- ferred from putrefaction, even during the warmer! feafons, for a long time. The membrane which lines the internal furface of the fhells of eggs, is found to be turgid with blood in advanced incuba- tion •, probably it performs the ofrke of oxigenation for the chick whofe lungs are inactive. Here ( 21 j Here arifes a curious and important queftion— •important^ becaufe, if it could be fatisfadtorily an- fwered, we mould be in pofferTion of a never-failing mean of increafing the energy of the fanguiferous fyftem :— < To ivhicb of the component parts of the blood does the oxigene become united^ and zvbat is its nature and properties? The inferences drawn from the experiments of Priestly and others, mew that oxigene is the fiorid- -ifying principle of the blood ; but what is the nature of that principle which is capable of being floridified* remains to be determined by experiment, i. It muft refide particularly in the colouring part of the blood. 2. It muft be common to the blood of all red blooded animals. 3. It muft have a great affi- nity for oxigene at a moderate temperature. Iron^ as a principle always prefent in red blood., feems to promife a happy explanation of this pheno- menon. The arguments which prefent in favour of this being the floridifiable principle, are, 1. It is al- ways prefent in the blood of animals. 2. It is found in the greatett, quantity in the colouring* part. 3. It has an univerfal agency in nature, " in colouring clays and ftones from the darkeft brown to the moft beautiful red." 4. The union of this fub fiance with oxigene * The blood is here fuppofed diftinguifhable into three feparate parts, ferum, coagulable lymph, or fibrous portion, and colouring part. — Ac- cording to the moft accurate analyfis of the blood, iron rcfides exclu- sively in the colouring part. C 22 ) oxigene produces a colour fimilar to that of the blood. 5. It is afubftance friendly to animal bodies, increaf- ing the denfity, floridity, and circulation of the blood. 6. It is one of the moft combuftible of the metals, and eafily reduced to an oxide (calx) by oxigene.— Does not the quantity of iron in blood accord with the degree of its floridity ? Thefe arguments do not appear fufficiently cogent to afford full fatisfaclion. The attraction of iron for oxigene at the temperature of animals, is not fufficiently great to account for that inftantaneous change which the blood undergoes in the lungs, or when expofed to oxigenous gas out of the body. The proportion of iron found in blood, does not ap- pear fufficient to account for its florid appearance ; but when we conficjer how much colour depends upon texture, this objection will not militate fo ftrongly. A quantity of red oxide of iron, equal in weight to that which is obtained from a given weight of blood, will not dirTufe that beautiful red appearance through fo large a mafs of water as the colouring matter from an equal quantity of blood. Red oxide* of iron does not remain in folution, in water, like the colouring part of the blood. Upon the principles of this theory, iron fhould be a more certain * The oxides of iron differ In colour according to their degrees of ox- ygenation J fome containing not more than from twenty to twenty-five parts of oxigene to the hundred; while others have this principle in the proportion of thirty-two or thirty-four hundreths; in which laft ilate they form a beautiful red, like carmine. Fourchoy, vol. i. p. 413. ( n ) certain remedy, always increafing the quantity of co- louring matter, and confequently the floridity.* Upon the whole, the prefence of iron in red blood is not fufficient to account for all the changes which take place in the lungs of animals. It is, therefore, neceffary to call in the aid of fome other of the com- ponent parts of the blood, by which we mall be able, either fingly or conjunctly with iron, to account for them in a fatisfaclory manner. Phofphorus, as another never-failing principle in the compofition of red blood, will afford much af- iiflance in the folution of this difficulty. The cir- cumftances, which a priori appear in favour of this fubftance, are, i. That it is always found in the blood of animals. 2. That its attraction for oxigene is very ftrong, and that at a low temperature. 3 . Hu- man * Chalybeates probably do no!: produce any great effect till rney are taken into the circulating mafs. They then form a bafe, or increafe the power of fome other fubftance exifting in the blood for the attachment of oxigene in the lungs. The blood, being more highly oxigenated, will ftimulatethe extreme arteries of the fyftem to greater action j and a greater quantity of caloric will be evolved from the combined ftate in a given time. Heat being one of the greateft ftimuli of animated nature, will further excite arterial action even to the moft minute ramifications. Ac- cordingly we find, that iron is *' confnlered one of the moft powerful tonics. It increafes the force of the heart, ads upon the fecreting powers, improves digeftion, and invigorates the whole fyftem." (Moore's Mat. Med.) That iron does enter into the blood by the lacteals, is proved by its being prefent in a preternatural quantity in the urine of perfons why have been under the ufe of it, and by their blood being of a more florid colour, containing more than a natural quantity of this fubftance. (Menghini quoted by Fourcroy and Chaptal.) — This explana- tion, of the operation of iron, accounts for its good effects in cachexie>, and fhews how and why it is fo effectual in reftoring the floridity of the /countenance and frefn colour of the whole body.— -May not iron be given in conjunclion with p hofyhorus, or the phgfphoric acid with advantage r ( 24 j man calculi become of a florid red, as does alio the blood, if oxigene be communicated to them by the. nitrous acid. 4. Animal fubftances receive the red dye better than any other. Probably thefe two phe- nomena are not only produced through the interven- tion of phofphorus, but alfo of iron, as both are prefent.* A great quantity of phofphoric acid is formed in the animal body. It enters largely into the compo- iltion of bone. It exifts in a naked ftate in the gaftric juice. It is found in the blood. In fact, it enters as an ingredient in almoft all the parts of ani- mal bodies. Large quantities are daily evacuated from the fyftem through the urinary organs, and by the ikin. As oxigene is the great acidifying principle through nature, phofphorus can only be brought into the acid ftate through the intervention of this principle ; and as it is impoiTible to conceive of any other way in which oxigene can have accefs to the blood but by the lungs, it is evident that this fubftance muft ac- quire its oxigene directly from the air during the paf- fage of the blood through that vifcus, or indirectly from fome fubftance which had previoufly undergone the * Whether thefe fubftances are formed in the bodies of animals or not, is not to the prefent purpofe to inquhe ; it is fufhcient to have afcertained that they are never-failing ingredients in red blood. If they are formed in animal and vegetable bodies, they are not fimple fubftances, as they are at prefent efteemed. The chemiftry of nature is not fufficiently attended to. The marine acid radicle, alkali, and probably calcarious earth can be formed in tha bodies of animals. ( 25 ) the procefsof oxigenation there.— There is no fub- ftance in the blood from which phofphorus could re- ceive oxigene in this indirect manner except iron. As the attraction of phofphorus for oxigene at the temperature of animal bodies is greater than that of iron, and as they are equally expcfed to the influence of this principle in the lungs, the former muft necefTarily undergo the greateft change. Thefe confiderations induce me to believe that the florid colour of blood is owing to iron and phof- phorus, brought into a ftate of union by oxigene. I am inclined to believe that thefe fubftances are united in the blood, becaufe oxigene is the bond of union between acids and metals, and becaufe the che- miftry of art can unite them through the interven- tion of carbone (pure coal.) Every circumftance favourable to their union exifts in the blood, toge- ther with the more fublime operations of the che~ miftry of nature* The idea then of the procefs, to which I have been conducted by this courfe of induction, is Amply this. During the pafTage of the blood through the minute branches of the pulmonary artery oxigene becomes united to phofphorus and forms the phofphoric* acid. The iron is reduced to the {late of red oxide, partly by the oxigene which it receives in the lungs, D and * Nature appears ftodious to acccmplifh this object;, by expoiing the greateft poffible quantity of furface to the oxigenous ga» ; the area of t',,s air veficles of the lungs being at leaft equal to the furface of the wholg body* ( 26 ) and partly by a communication from the acid. When thefe fubftances have undergone a certain de- gree of oxygenation, they become united by a fur- ther addition of oxigene ; probably at the fame time 'fome other part of the blood may be combined with them, which, when exiting in a perfect ftate of union, constitute the colouring of the blood. Dur- ing this union, which not only takes place in the blood while in the lungs, but alfo in other parts of the arterial fyftem, carbone is difengaged* and when the blood is undergoing a change from arterial to venal, it unites with cxigene, and is exhaled from the lungs and furface* of the body in the form of carbonic acid, From this view of the fubject I maintain that fome of the immediate principles of the blood become the bafe of its colouring part. — Are the laws of the chemical attractions modified by the living; principle in this function, or is it, like di • geftion, a pure chemical procefs? This theory, which appears to me to be fupported by a number of facts and ftrong analogies, is fufficient to explain all the phenomena connected with refpira- tion. The affinity of phofphorus for oxigene, ac- counts for the rapid decompofition of oxigenous gas in the lungs; the union of phofphorus and iron, for the colour of the blood. It ihews how blood is changed from venal to arterial, and from arterial to -venal. It explains why the blood becomes more red when expofed to oxigenous gas, although cover- ed 8 Sec Ncte pa^e 12. ( 27 ) ed with a ftratum of ferum of the thicknefs of two inches and an half', and why this change cannot take place when it has even the flighteft covering of fa- liva, oil, or water. It fhews why azotic and hydro- genous gafes are unfufceptible of decompqfition in tht kings. And it may ferve, in fome meafure, to throw light on the deleterious operation of carbonic acid in the lungs. The different temperatures of animals, and the different degrees of floridity in their blood, are likewife explicable in a degree by this theory. It not only affords a fatisfactory expla- nation of the formation of phofphoric acid in the blood, but alfo explains the fpontaneous ccmbuf- tion of animal bodies, and may, in fome meafure, elucidate the gout and ftone. Oxigene^ deprived of that principle which maintain- ed it in the gafeous ftate, and having afTumed the folid form, carries almoft all its caloric with it. The ftate in which oxigene exifrs in the air, is that of elaftic fluidity. It is capable in this condition of having its bulk increafed like all other fubftances in nature, by the addition of caloric. But, when deprived of that portion of caloric which overbalanced the attractive power between its particles, and maintained it in the aeriform ftate, it afTumes the folid form : in this con- dition it exifts in the oxides of metals, concrete acids, &c. On account of its ftrong tendency to combination it has never been obtained a in feparate ftate, or there is no doubt, but that, like other bodies, it might be brought into the intermediate (late of eMic fluidity and ( 28 ) and folidity. This may yet be effected by the con- joined action of cold and preffure. In water and ma- ny of the acids, oxigene approaches nearly to this condition -, in the former, its proportion is as eighty- five to fifteen of hydrogene. Lavoisier, when on the fubject of afcertaining the quantity of caloric difengaged during different fpecies of combuftion, makes it an important defi- deratum in chemiftry, to find a method for determin- ing the quantity of caloric which oxigene takes with it when it affumes the folid form. He fuppofes, that the oxigene entering into the compofition of the oxigenated nitric and muriatic acids, takes caloric with it •, hence (fays he) " the violent and dangerous deflagrations which the neutral falts, in which thefe acids enter as components, produce with charcoal and many metallic fubftances." The violent explofion of the aurum and argentum fulmmans, can only be explained upon this principle. Amoniac (volatile alkali) is requifite to the forma- tion of both, which is itfelf proved to be compofed of the bafes of hydrogenous and azotic gafes (hydro- gene and azote.) From the analogy of thefe ele- mentary fubftances with oxigene, it is prefumeable that they likewife take caloric with them when they affume the foiid form. The caloric thus exifting in the folid form in the ammoniac, and alfo in the ox- igene of the oxide of the metal, being rapidly difen- gaged by the formation of new combinations, is Ef- ficient to account for all the appearances which thefe iubftances, I 29 ) fiibftances prefent. Analogous to the fulminating gold and filver are gun-powder and the common pulvus fulminans, which explode equally well in vacuo as in open air.— -During the explofion of ful- minating gold and filver, which will take place in copper tubes, water and azotic gas are produced : the products, after the explofion of the pulvus ful- minans, and gun-powder, are entirely gafeous. — • How can the production of thefe various fluid fub- ftances from folids be explained, unlefs it is allowed that caloric, under certain circumftances, can take the folid form ; and that the fame caloric, in confe- quence of an alteration taking place in the fubftance by which it is held in chemical union, mail anume' another fcate, and be the caufe of liquidity and elafxic fluidity ? Caloric is, no doubt, in a degree condenfed in the natural (late of the air ; for if thin glafs bubbles, filled with air, be placed under the receiver of an air-pump, they will burft •, bladders, partly filled with air, under fimilar circumftances, immediately fwell — the latter fact takes place with bladders partly filled v/ith air when taken to the tops of high mountains. Mr. Boyle found air to expand in vacuo one hundred and fifty times ; but this falls yaftly fhort of the bulk which it is capable of occupying. It is impofiible to limit the bounds of the con- denfation of air. Boyle made it thirteen times more denfe than it was before he applied the prerTure. Halleti ( 3° ) H alley fays that he has feen it comprefied into one- fixtieth of its natural fpace. Hales condenfed it thirty-eight times. It has been lately made to occupy one hundred and twenty-eighth part of its former bulk. It is evident, that in the condenfation of air, ca- loric is not fqueezed out, for it inftantaneoufly re- turns to its former condition when the condensing power is removed, as may be ktn in the familiar in- fiance of the air-gun. It would not only return to its former volume, but would actually pafs infinitely beyond it, was it not for the mechanical preflure of the contiguous atmofpherical column. If in the comprerlion of air caloric was forced from between its folid particles, it would be in a free or difengaged ftate, and confequently would manifeft itfelf by heat. In the expanflon or condenfation of air there is neither an addition nor diminution of caloric, there cannot be of the folid matter, caloric can then be made to occupy a greater or lefl'er fpace than it naturally does in air; its particles cannot be in contact even in the more, condenfed ftate of air. If caloric is matter, and if it be fubject to the laws of the che- mical attractions, and can exift in bodies not only as water does in a fponge, but alfo in combination ; why may it not become part of their folid fubflance ? From what has been advanced above, it appears that oxigenous gas is decompounded in the lungs. That its folid matter, oxigene, becomes the fioridify- ing ( fcf ) ing principle of the blood, and that iron and phof- phorus are the fubftances capable of being floridified. It was then rendered probable from the nature of fluid and folid, and from feveral phenomena explica- ble upon no other principles, that the bafes of gafes when aHuming the folid form carry caloric with them I now think it probable, that the caloric thus united with the oxigene* in. the blood, is evolved in the extreme arteries, and is the greater!: fource of heat to animal bodies. In maintaining an opinion that heat is not com- municated to animals by the blood from the lungs, but that it is evolved in every point of the body which contains arteries, I know that I fhall act in oppofition to the fentiments of great names— Ami- cus P *l at o fed arnica Veritas magis. Although we do not know in what manner arteries evolve combined caloric into the free or fenfible rtate, yet that its evolution is connected with the action -of the arterial fyftem is an obvious truth. But whether this depends upon the action of the ar- teries, or upon that caufe by which arterial ac- tion is directly produced, will be difficult to deter- mine. * " One hundred parts of phofphorus require one hundred and fifty- four parts of oxigene for faturation." It has been already obferved, that the proportion of oxigene in the red oxide of iron is as thirty-four to onr hundred. If one hundred and thirty grains of oxigene are combined with the blood in one hour, three thoufand one hundred and twenty mud be fixed in the courfe of one day, which appears to me to carry combiner! caloric fufhcier.t to be adequate to the effect of the heat of the humaa bod). ( 3* ) mine. We certainly know, that arteries pofTefs the power of decompounding the blood, and of recom- pounding it again, as in the various fecretory organs of the fyftem. Analogous to this, is that change which the blood Undergoes from arterial to venal, as it paffes through the extreme arteries into their an- aftamofing veins. As the affinities of bodies for caloric, and capacity for containing it, are changed when they undergo any chemical alteration, it is eafy to conceive that blood, when it undergoes the change juft mentioned, mail throw out a quantity of fts combined caloric, which will manifeft itfelf in the feniible form. During this change of blood from red to black, difengaged oxigene may unite to its car- bone, and form the carbonic acid which is exhaled in fuch quantities from the lungs and fkin.— The blood being deprived of its oxigene, by its union with carbone, by a quantity of phofphoric acid going to the formation of bones and other purpofes, and by a portion of this acid conftantly palling off by the kidneys and fkin •, the fyftem at the fame time continually generating phofphorus -, it is again pre- pared to attract oxigene in the lungs, and thus is kept up the perpetual round of changes in the blood from venal to arterial, and from arterial to venal during the exiftehee of animals. The idea of animal heat, which is deduced from the theory of refpiration already given, is limply this. By the decomposition of oxigenous gas in the lungs, a quantity of oxigene is communicated to the blood, ( 33 ) blood. The oxigene thus combined carries a large portion of its caloric with it; which is gradually evolving by the oxigene forming new combinations during the circulation, and which becomes more com- pletely evolved in the extreme arteries by that power which changes blood from arterial to venal. This idea of animal heat refts on the following obfervations, and its eafy application to the explanation of phenomena. The heat of animals is in propor- tion to the extent, perfection, and vigour of their lungs : thus birds are warmer than terrene animals ; thefe latter are warmer than the amphibious, and thefe frill more fo than fillies, whofe temperature is fcarcely above that of the element in which they live. Animals appear to deftroy oxigenous gas in propor- tion to their temperatures. The blood of animals is found to correfpond with their lungs; that of land animals containing a greater quantity of crafTamen- tum, and being more florid than thofe which live both on land and in water, and thefe latter again more fo than fimes, whofe blood is pale, aqueous, and in fmall quantity. The ftate of the blood does not only differ in the different claffes and fpecies of animals, but alfo in individuals of the fame fpecies : " in in- fants, delicate women, and weakly men, it is paler, and lefs difpofed to coagulate, than in robuft healthy perfons. The blood is thin and pale coloured in cachexies, but in difeafes of an oppofite diathefis it is highly florid, and contains a large proportion of era Ma men turn, correfponding with the weaknefs or E ftrength ( 34 ) ftrength of the pulfe. Any caufe increafing the energy and a&ion of the arteries, increafes heat* Every part of the body containing arteries, is fuf- ceptible of inflammation,* or an increafed genera- tion of heat, even the vafa vaforum of the lymphatics •, and that in proportion to vafcularity and fenfibility. Inflammations are generally circumfcribed, which would not be the cafe if heat was communicated through the body by a mere difTufion from the lungs. Every part of the body is capable, in a certain de- gree, of fupplying itfelf with heat, according to its exigencies. Children have been born with marks of the fmall-pox, the fuppuratory procefs of which difeafe implies inflammation. If * Inflammation is confined to the extreme arteries. The phenomena Of this difeafe all concur in fhowing that there is an increafed impetus of the blcod in the vetfels of the part affected \ and, as at the fame time the action of the heart is not evidently increafed, this is fufficient reafon to conclude that the increafe of heat in the part is owing to an increafed action of the vefTels independent of the heart. An increafe of action in any fet of veffels produces preternatural heat. Active inflammation may there- fore be defined an augmentation of that power by which ca- t'ORIC IS EVOLVED FROM THE COMBINED TO THE FREE STATE. A topical accumulation of excitability or ftimul ability will render the vef- fels of that particular part more fufceptible of the action of the oxigenated blood, by which means their action will be increafed (not their energy), and confequentiy a greater quantity of blood will circulate through the part in a given time than in health, and by this means a greater quantity of heat be evolved. Inflammation may thus continue by the part generating its own flimulas, till nature relieves the veffels by refolution or fuppuration: but if the excitement of the part be raifed too high by the ftimulant opera- tion of heat, that principle upon which the ftimulus ads will be worn out j the part being thus deprived of that principle, which, when prefent, mo- dified the agency of feptic powers, it will confequentiy be left to the de- ftrucYive action of external agents, decomposition will eufue, and the components of the fkin, mufcular fibres, &c. form binary combinations, which conftitutes fphacelus.— -Upon this principle of a part generating its own heat, the continuance of inflammation can be accounted for, without fuiipofing a fpafm to exift in the extreme ends of arteries to fupport their action, or without recurring to a vis msdicatrix for its formation. ( 35 ) If the heat of animal bodies was all evolved in their lungs, the following proportions would be found to be juft. i . The parts of the animal body would be cool according to their diftance from this fuppof- ed centre -, for it is an eftablifhed law in Nature, that heat mail decreafe as it recedes from the fource from which it originated. 2. No part would be fufcep- tible of an increafed degree of heat. 3, No part could refift the topical application of cold. 4. The foetus in utero would generate no heat, and confe- quently would be unfufceptible of inflammation. The accurate obferver of the phenomena of animal bodies will perceive that the reverfe of thefe is the ha, If the animal body had not the power of preferr- ing itfelf nearly at one uniform temperature, it would be imporlible for it to exiil. Heat is an agent which regulates chemical attractions: if the body was raifed much above, or funk much below its natural ftandard, the chemical operations which it perfoHns would be varied, new combinations formed, and death enfue. It was, therefore, neceflary that the temperature of animal bodies mould be nearly equa- ble, whether they were expofed to the cold of Sibe- ria, or to the burning heat of the torid zone, To fupport this regularity, Nature has made abundant provision. In the frozen regions of the earth, and during cold feafons of the year, atmof- pheric air contains a greater quantity of oxigenous gas ( 36 ) gas under a given volume, than it does in warm climates and feafons^ and, according to the idea, p. 30, a greater quantity of caloric is contained in condenfed than in rarefied air, and moft certainly more oxigene. Under thefe circumftances a greater quantity of oxigenous gas will be decompounded in the lungs, in a given time, than in warm climates and feafons, and confequently a greater quantity of oxigene fixed in the blood. If this fluid is ftimulant to the fanguiferous fyftem in proportion to its degree of oxigenation, the animal fyftem will be able to pre- ferve one uniform temperature, whether it be ex- pofed to an atmofphere at the freezing point of mercury or at the boiling point of water.* When the atmofphere is cold, and confequently the animal body deprived of a great quantity of heat by its mechanical contact, the air is moft replete with ox- igene and caloric, which are the great caufes of ani- mal heat. The contrary takes place when animals are furrounded by a warm atmofphere. According to my arrangement of this fubject, I have only to mention the effect of refpiration on the action of the heart. The connection between the ftate of the breathing and the pulfe has been noted by Boerhaave, Haller, Zimmerman, M'Bride, Gregory, and every other writer on phyfiology and pathology. * It is a well known fact, that the human body is not colder in the northern regions, where mercury has been known to freeze ; and the ex- periments of Biagdin and Fcrdvce mew that its temperature is not much increafed when expofed to air where Farenheit's Thermometer flood above two hundred and forty degrees. I 37 ; pathology. This natural connection between thefe two vital functions has been brought to account for the fuecefs of Hipprocates in curing difeafes ; who 5 it is faid, almoft neglected the pulfe, but attended particularly to the ftate of the breathing. Goodwyn fuppofes that the heart is indebted only to the chemical change which the blood under- goes in the lungs for the fupport of its inceflant ac- tion. He therefore denies that the dilatation of the thorax is the final caufe of refpiration ; and arTerts that the circulation of the blood through the lungs, even iuthe nioft perfect {late of expiration, is furn- cient to fupport the life and health of animals. The death of animals by drowning and ftrangulation, he fuppofes to be owing to venal blood paffmg from the right to the left ventricle of the heart unchanged. Hales and Haller fuppofe that the dilatation of the lungs is neceffary to the free tranfmiffion of blood through them. The former of thefe authors goes fo far as to fuppofe that this is the only ufe of refpiration. It appears to me that the truth (as ufual) lies be- tween thefe two extremes : the blood not only ap- pearing to ftimulate the heart in confequence of be- ing oxigenated in the lungs, but alfo by mechani- cally diftending it. If the conclufion of Goodwyn was founded in Nature, would there be that intimate connection be- tween ( 3* ) tween the frequency and force of the heart's action and the frequency and fullnefs of refpiration? Would the fufpenfion of refpiration produce that turcrefcence and rednefs of the face which it is inva- riably found to do ? From Hales's account of his experiments on dogs, it appears that the circulation of the blood was fupported in a kind of mechanical manner, by forcibly diftending the lungs with air, which muft have been much vitiated by its having been frequently taken into the lungs of the animal. Cullen obferves, that " the tone of the arterial fyf- tem depends upon its tenfion." I know of no rea- fbn why this will not apply to the heart in fome mea- fure. The right or anterior ventricle of the heart acts without the ftimulus of arterial or oxigenated blood. This Goopwyn fays is becaufe the venal blood is its proper ftimulus. Does it not act by the ftimulus of oxigenated blood in the foetus ftate ? — ■ According to Goodwyn's idea, a different organi- zation is implied in the ventricles of the heart, to render each fufceptible of its peculiar ftimulus, which is not proved. Upon the whole, I am induced to conclude, that the uninterrupted aciion of the heart is owing to the evolution of caloric from the oxigene of the blood as it paiTes from the lungs to the heart, to the oxi- gene which changes the blood from venal to arterial, and to the mechanical aciion of the blood. Is ( 39 ) Is the tenacity of the hearts of animals, for their vis infita or irritability, increafed in proportion to the diminution of the power of their refpiratory organs in decompounding oxigenous gas ? — and do their temperatures decreafe in the fame ratio ? From the doubts, difficulties, and uncertainties which occur in attempting to explain the phenomena of refpiration (and indeed of almort every other function of the animal ceconomy) I am convinced that much more is ftill to be done. There are not yet a fufficient number of facts collected, and experi- ments made, to conftitute the ban's, or ferve as data for reafoning in a fatisfactory manner ; I have no doubt, and I have analogy in my favour, that this will foon be done. A genuine fpirit of investigation prevails — Revolutions are taking place in every fpecies of knowledge — Medicine does not remain ftationary ; and from the unbounded profpects which chemiftry opens to view, I have no doubt but that a period is commencing which will mark a glorious sera in the hiftory of this fcience. FINIS. o f> = ^ ^ 1 r^O rn L — *T1 g^ss ro (— en ~m ^ > — j c/>