INTEGUMENTS. 



fiinrft," and " fubfequertt to tlie dally ufe of it, the urine 

 flawed more plentifully, and became Icfs punfjent." An 

 obfenvatioii precilely iimilar is made by Mr. Cruikfhank : 

 *« a patient of mine, witli a rtritlurc of the ocfojjhagus, re- 

 ceived nothing, cither folid or liquid, into the ilomach for 

 two-months ; he was exceedingly thirlly, and complained of 

 making no water. I ordered him tlie warm bath for an hour, 

 evening and morning, for a month ; his thiril vanifhed, and 

 he made water in the fame manner as when he ufed to drink 

 hy the mouth." Anatomy of the Abforbing Veflcls, 

 p. lot. 

 , Dr. Currie ftates further, concerning his patient, that the 

 difcharge by urine alone exceeded much in weight the wade 

 of Ibs whole body ; and it cannot be doubted, he adds, that 

 the difcharge by ftool and perfpiration exceeded the weight 

 of the clyllerg. Thus it appears that the egella exceeded 

 the ingefta in a proportion much greater than the walle of the 

 body will explain." That cutaneous abforption affords the 

 rt»ly adequate folution of this phenomenon is an irrefillible 

 conclulion. Still, however, this is denied. When forced to 

 confefs that there are cafes where tlie egefta exceed the in- 

 gefta, and which can oi.ly be accounted for by abforption, 

 tjie opponents of the cutaneous inhalation deny this funflion 

 to the {kin, and bellow it moil gratuitoufly on the lungs. 



Many other examples might be cited, in which the body 

 evidently acquired weiglit from fome other quarter than by 

 the food or drink, lialler has many futh inftances. Rye 

 and Linings gained feveral ounces by expofure in a moill at- 

 mofphere : and Fontaua experienced a fimilar occurrence. 



Some faSs, wliich oppofe the notion of inhalation by the 

 furface of the il<in, have been obferved in the applications of 

 medicated fubftances to the body. Seguin made numerous 

 experiments of this kind, with folutions of muriate of mer- 

 cury on fyphilitic patients : we are informed, that in cafes 

 where the epidermis was perfeftly found, neither the known 

 efFefts of mercury on the body, nor any amelioration of the 

 venereal fymptoms, was ever obferved. He alfo immerfed 

 his own arm in a folution of two drachms of the mercurial 

 muriate in ten poundsof water. At the tempenitureof I0° 

 and 28^ of Reaumur, no part of the fait was miffing at the 

 end of the experiment ; but when the bath was at 18^ of the 

 fame fcale, there was a lofs of one or two grains of the mu- 

 riate in the hour, though the quantity of fluid was not dimi- 

 niflitd. It appears to us that the experiments on the whole 

 fhew that the muriate of mercury was not abforbed ; we can 

 hardly admit that two grains were taken up as ftatcd in this 

 account. The entrance of fo large a quantity of this very 

 r aftive preparation into the fyftcm, mull have been attended 

 I with very unpleafant effects on the fubjeA of the experiment, 

 I which do not fcem to have occurred. 



The effcfts produced on the odorous properties of the 

 urine, by expofure of the body to oil of turpentine, are well 

 known. By inhaling the vapour of this fluid, the violet 

 fmell is imparted to the urine very fpecdily : even a fingle full 

 infpiratiou ,is fuftcieiit to produce the effect. Walking in a 

 room where it has been fpilled will operate in the fame way. 

 It has been proved by experiment that the lungs are the 

 organs by which the abfirption takes place, and that the 

 fluid is not taken up by the fl<in. Dr. Roufl'eau, of Phila- 

 delphia, expofed.his body freely to the turpentine vapour, 

 breathing through a pipe, which communicated v/ith the ex- 

 ternal air, and had no conneftion with the air of tiie room. 

 No efFe£l was produced on the urine. He immerfed his arm 

 in fpirit of turpentine for two hours, luting the veffel con- 

 taining it to the arm, fo that no vapour could efcape ; no 

 change was perceptible in the properties of the urine. He 

 fmeared hit body all over fcvcral times with tlie iyirits c£ 



turpentine, guarding againfl the inhalation of the vapour o^ 

 the lungs, by breathing- the external air through a tube. 

 ?le continued this for fome time, imtil tiie fuifacc \viis irri- 

 tated, and the pulfe quickened ; the refult was the fame?. 

 Thefe experiments were frequently repeated, and with the 

 fame refult, whether the f])irit of turpentine was employed, 

 or camphor, garhc, or mulk. Currie'e Med. Rep. v, i.' 

 chap. 19. 



'l"he exhalant veffels of the flcin arife in the exterior ca- 

 pillary fyllem, which furrounds the corion, and which afl^ords 

 the point of termination of the cutaneous arteries. Tlioy 

 draw from this lource the fluid which they pour out on the 

 epidermis. We are entirely ignorant of tlieir form, length, 

 courfe and direction : but the phenomena of the cutaneous 

 difcharge, and of injections prove their exiftcnce. They do 

 not feem to be equally abundant in all parts : in the face and 

 chell they are numerous, fo that we fweat eafily in tliofe 

 parts ; the number is fmaller in the back and limbs. Sweat 

 IS very feldom obferved in the palms and foles : but there ii 

 great variety in thefe refpcfts in different individuals. 



It Appears from experiments, that a confiderable difcharge 

 takes place from the (kin liabitually, although not in a form 

 cognizable by our fenfes. This is called inienfible perfpira- 

 ration, or tranfpiration. Under particular circumflnnces, 

 the cutaneous difcharge confifts of fluids poffefling very fenfl- 

 ble properties : this is called fweat. The epithet infenfible 

 is apphed to the former, todiilinguifli it from the fweat, but 

 under certain circumllances it may be rendered obvious to 

 the fenfes. It has been often an"erted that a vapour inay be 

 obferved to arife from the body, and may be recognized by 

 its fliadow againil a white wall m the fummer. This is obferved 

 more readily in a denfe atmofphere. Haller faw a kind of 

 cloud or fmoke ariflng from the face, hands, and indeed 

 every part of the naked body in the fubterraneous exca. 

 vations ofClaullhal and Rammellberg. A ftill more ob- 

 vious demonflration of the tranfpiration is yielded by holding 

 a finely pohflied metallic furface near the Ikin ; the watery 

 vapour is condenfed by the metal, and clouds it. Under 

 ordinary circumftances, the whole difcharge is evaporated as 

 it is produced, and paffes off in this invifible form. As all 

 bodies abforb heat in clianging from a fluid to a gafeous form, 

 this evaporation mull have a very powerful efieCt in regulating 

 the temperature of the animal frame. _ When the nature of 

 our clothing confines the perfpiration, and prevents its evapo- 

 ration, an unpleafant feeling of heat is produced ; this is_par- 

 ticularly obferved when the body is covered with oiled lilk. 

 On the other hand, expofure of the Ikin in a nakod_ Hate, 

 particularly in the wind, has a very rapid and powerful cool- 

 ing effect. The ' importance of this funftion in regulating 

 our hfat did not efcape the notice of that fagacipns obferver 

 Benj. Franklin : " during tlie hot Sunday at Philadelphia, 

 fays he, in June 1750, when the thermometei- was up at 

 loo" in the fhade, I fat in my chamber without exercife, 

 only reading and writing, with no other clothes on than 

 a Ih'rt, and pair of long linen drawers, the v.indows all open, 

 and a bri/k wind blowing through the houfe. The fweat 

 ran off the backs of my hands, and my fliirt was often fo 

 wet as to induce me to Call for dry ones to put on. My 

 body, however, never grew fo hot as the air, Or as the inani- 

 mate bodies immerfed in the air.'" (Letters and Papers, 

 p. 365.) It does not appear that Franklin actually meafured 

 his heat ; but he makes the inference of his comparative cool- 

 nefs from remembering that all the bodies about him, even 

 the fhirt out of his drav\er, felt warm to the touch ; and l»e 

 concludes that he was kept cool " by the continued fweatjng, 

 and by the evaporation of that fweat.' 



Frobfbbly fweat is only an iocreafed quantity of the fame 



kuid- 



