INTEGUMENTS. 



kind of fluid w UK i\m of the tranfpu-ation : very fmall par- 

 tic'es of fluid are obfei vcd on the ikin, and they unite into 

 larger and larger drops. Heat is the moft common caufe of 

 fwcating, as it is a very powerful means of exciting the ac- 

 tion of the heart, on vl'.'.ch this phenomenon depends in 

 mar.y cafes. : hence war .. ^■r and the warm bath are powerful 

 caufes. Strong bodily cx'.rticn, and warm food, by llimu- 

 lating the vafcular fyftcn , produce the fame cffeft. Fear, 

 and other afTedions of ll;e mind, fainting, and various mor- 

 bid dates of the frame, ai!\) produce fweating. We cannot 

 r.aT-.cany particular degr. . of heat at which iweating is cer- 

 tainly produced : and llio pulfe is often very greatly accele- 

 rated in difeafe without this confequence. Sometimes a 

 particular part of the body only fweats : fometimes one 

 iidc, as Haller has noticed in his own perfon. 



Bichat enquires whether the nerves have any influence on 

 the cutaneous difeiiurge. He obferves, that in palfied pa- 

 tients fweat takes place on the difeafed as well ;.s on the found 

 ijc " I lately," fays he, " attended at the Hotel Dieu a pa- 

 tient, in whom the left fide of the body was rendered per- 

 feftly paralytic, in confequence of an apopleftic attack : yet 

 he fweated only on this fide. Examples of the oppoiite 

 phenomenon arc adduced ; but they cannot invalidate the 

 common obfervation that the dilcharge is equal on both 

 fidps. Is it not well known, that when the nervous adion is 

 entirely annihilated in a paralytic limb, bliilers affedl it in the 

 ufual manner ? Do convulfions, in \\'hich the nervous adion 

 is incrcafed, augment the cutaneous exhalation ? Have the 

 Uates of acute fenfibility, where there is in the cutaneous 

 nerves fo great a fufceptibi ity of impreflions, any known 

 influence on perfpiration ? Let us tlien confefs, that in cuta- 

 neous exhalation, as well as in fecretion, we are entirely ig- 

 norant of the nature o^ the nervous influence, if any fuch 

 exift." 



Tlie difcharges by the fl<in and the kidney feem to be re- 

 garded by phyfiologills as the principal means by which the 

 refiduary matter of luitrition and digellion is expelled from 

 the body ; and they have attempted to (hew the ratio which 

 tlicfe bear to each other, to the pulmonary exhalation, and 

 to the feces. We have not derived much information from 

 thcfe labours, which merely prove, in a general manner, that 

 the difchargc is cffei'tcd througli tJie internal organs in cold 

 climates andfeafons, and through the fliin under oppofite cir- 

 cumllances. In this refped, the kidney ar.d the Ikin are always 

 in oppofite rtatcs in rehitian to each other: in winter the urine 

 is iTiuch loaded with fubllances, and in fummer the perfpira- 

 tion has a fait tafte aiid other peculiar characters, arifing fom 

 matters which it does not contain in the former feafon. 

 Every individual mufl have obferved in iiis own ]perfon that 

 vvliile he fiveats freely no urine is collefted in the bladder ; 

 and, that when the cutaneous difcharge is interrupted, the 

 fecretion of the kidney goes on very actively. 



We do not know much about the pulmonary exhalation; 

 cither as to its quantiy, its nature, or its relations to the 

 cutaneous difcliarge : but that the tv.o organs very power- 

 fuily influence each other, is rendered very obvious by the 

 phenomena of difeafe. The effeif of cxpofure to cold and 

 moiibire in exciting pulmonary aireflions, and the difpofilion 

 to fuch diforder; in the winter, vthen the cutaneous cxha- 

 lanis are lefs adive, are well known. 



Wc often have occafion to obferve a manifeft coimeSion 

 betweei! the perfpiration and the alvine difcliarges. 



When the extent of the exhahng organ, the innumerable 

 tubes by which it is penetrated, the quicknefs with which 

 wc can even fee the perfpiration produced, are regarded, we 

 fliall exm-ct to find thai the quantity of the difcli u-ge is very 

 confiderabie. Although it wot known t« the ancients, who 



had noticed its influence on the health, and introduced it int« ' 

 their pathology, we find little detailed information concern- 

 ing this funftion before the feventeenth century, about the 

 beginning of which it became the fubjeft of the moft pa- 

 tient refearch, and of the moft extenlive experiments per- 

 haps ever undertaken. Sanctoritis, a Venetian phyfienn , 

 dedicated thirty years to his experiments, which confift'- * 

 chiefly in weighing whatever he ate and drank, as well ;i 

 what he difcharged by urine and ftool. From him the i >• 

 fefible perfpiration has fometimes received the epithet oi 

 Sandorian. His example was followed by fev^:;;! perf ^^ 

 in difi"erent countries; by Dodart in France; by K< :', 

 Robinfon, Rye, and Home in this country- ; and by L:- 

 nings, in South Carolina. Even our gay monart'i, 

 Charles II. amufed himfelf with fome experiments c '. 

 this fubjed. Something muft be taken from the nuiviber^ 

 exprefling the quantity of perfpiration, on account of t! f 

 pulmonary exhalation, the mucus of the air pafiages a"u 

 nofe, and fpitting. For, in the experiments now alluded 

 to, all the diiTerence between the ingefta and tiie egefta ;;• 

 fel down as lofs by infenftble infpiratioii. 



In the experiments of Home, in Scotland, the food 

 amounted to 41b. 3 or.. ; the feces to gi oz. ; the urine to 

 2 ', lb., or 3:' lb. ; the perfpiration, iu the courfe of an hour, 

 varied from two-thirds of an ounce to 40Z., and even fix 

 under expofure in the fnn. In the twelve hours of night, 

 the perfpiration varied from 12 to 18 oz. ; and in 137' hour* 

 the difcharge amounted to 3 lb. 3;^ oz. ; and on another occa- 

 fion, to 2 lb. 6,^ oz. 



Rye, who lived at Cork, in Ireland, found the urine in 

 the winter feafon to amount in one day to 42 ^'j, oz. ; the 

 perfpiration to J3 oz. in fpring, the urine wae 40 oz. ; the 

 perfpiration 60: in fummer the numbers were 37 and 63. 

 The average daily quantity of urine, therefore, was rather 

 lefs than 40 oz., and that of th.e perfpiration 56^ oz. The 

 average daily amount of the feces was 4^ oz. ; that of the 

 food 96 oz. The large quantity of perfpiration in the 

 winter is chiefly made up of what is produced during the 

 night. 



Keil found the medium quantity of perfpiration to be 

 31 oz. ; of urine 38 ; of feces 5 ; food 78. 



Robinfon allows that the urine is diminiflied, and the per- 

 fpiration incrcafed in a very fenfible manner in the fummer, 

 fo that the average number of ounces of the former is in 

 fummer 27, in winter above ^o. In the fummer months 

 the perfpiration and urine are as j and 3, in the winter a» 

 2 and 3 ; in .April, May, October, November, and Decem- 

 ber, they are nearly equal. In a young perfon he eftimates 

 the ratio of the perfpiration to the urine as 1340 to icoo ; in 

 an old one as 967 to 1000. He makes the average quantity 

 of foud 8602., and 58 when he was old ; the urine 55 and 

 z8 ; the perfpiration 46 and 27^ ; the feces ji and 3J. 

 Thus the food and all the excretions are diminilhed as age 

 advances. 



Hartman, in Germany, found the food to be 8 oz. ; the 

 urine 28 ; feces 6 or 7 ; and perfpiration 4y or 46. 



Dodart, in France, found that the perfpiration was to 

 the feces as 7 to 1. He eftimates the difcharge in fum- 

 mer at 40 oz. 3 dr. 26 gr. ; in winter at 26 oz. 46 gr. 



Sandorius, in the warm and humid air of Venice, took 

 8 lb of food ; the perfpiration amounted to j lb. ; the feces 

 to 4 oz. ; and the urine in the night to 16 oz. ; in the twenty, 

 four hours to 44 oz. 



I.,inings has given us very accurate accounts of his expe- 

 riments, which were performed in South Carolina. From 

 his labours, as well as from thofe of Robinfon, in Ireland, it 

 appears tliat the perfpiration is moft abundant in the warm 



mortlis 



