KIDNEY. 



(jiiantity of urine is fo remarkably augnipiited in Jiabetts, the 

 flcin is parched and dry. 



The quantity of food, and more particularly of drink, in- 

 fluences very greatly that of the urine ; and feveral phyfi- 

 ologifts reprefent the two as nearly equal. The effect of 

 aqueous drinks, however, will be conliderably incdified by 

 tlie ftate of the cutaneous difcharge. If the individual be 

 warm and llrong, a great part of fuch drinks is difTipated by 

 the flvin : in a weaker Hate of the body, combined with ex- 

 ternal cold, it is difpofed of by the kidnies. The labourers 

 in harvcll will often drink fome gallons of liquor, while pro- 

 fecuting their hard work under a hot fun, without any in- 

 creafed urinary difcharge ; the perfpiration, however, is un- 

 commonly copious, and its evaporation has a mod favourable 

 cfFcft in keeping the body cool. The liquors which in- 

 creafe tlie urine moll remarksblv are thofe of an aqueous 

 kind, fuch as water, vegetable infufions, weak beer, cyder, 

 &c. taken cold. Stimulating drinks, fuch as the ftronger 

 wines and fpirits, and warm fluids, excite the fyllem in 

 general, and are more likely to be difpofed of by the Ikiii. 

 The quantity of urine, afcertaincd by aftual experiment, has 

 varied confiderably. The accounts of Hartman, Robinfon, 

 De Gorter, Keii, Rye, Home, Sanclorius, and Linings, 

 give us the follcwing numbers of ounces in t.venty-four 

 hours; iH, 31, 36, 38, 40, 44, 50^, 64: the average of 

 the whole will be 49 ounces. 



The qualities of the urine are affecled, in many inllances, 

 in a very obvious way by the nature of the food. As this 

 fecretion provides for the removal from the body of the re- 

 fidual and cxcrementitious part of our aliment, we cannot 

 doubt that it mull be very cITentially influenced by the pro- 

 perties of the food. Rhubarb, beet root, madder, and 

 other fubllances affeft its colour. Fourcroy mentions a 

 man, who conceived that he voided blood, but was perfeftly 

 free from pain, and all fymptoms of uriiiary affciftion. He 

 had eaten a large quantity of beet root for feveral days ; and 

 on leaving this off, the urine recovered its healthy appear- 

 ance. (Sya. desConnoifr. Ciiim. t. 10. p. 170.) Garlick 

 and onions affecf its fmell ; oil of turpentine gives it an 

 odour refembling that of violets ; and afparagus imparts to 

 it a remarkable fetor. Several other vegetables, fuch as 

 fennel, carrots, parfnips, &c. produce alfo very feniible ef- 

 fects on its fmell. A very ftriking inllarce of change in its 

 properties, produced by an alteration in the food, is afibrded 

 in the treatment of the diabetes mellitus by animal diet. 

 SeeDi.\nF-.TES. 



The alteration of the urine by the food is more particu- 

 larly evinced in individuals, whofe digclUve organs are not 

 ftrong : hence the ftate of the urine is an important fymptom 

 in f-.'.ch cafes. 



Two or three kinds of urine are diftinguifhed, according 

 to the interval between the repaft and the time of evacuating 

 the fluid. The fsri, difcharged within a very ihort time 

 after drinking, is called urine of the drink (urina potus), or 

 crude urine. It is often evacuated fo ioon after drinking, 

 and has fo little of the dillinguifliing characters of urine, 

 that it has given rife to the notion already mentioned of a 

 (hort communicatKjn between the llomach and bladder. It 

 appears almoll like a mere water, and has neither the fmell, 

 colour, nor weight of urine : it mull be regarded as an ex- 

 tremely diluted form of the fluid, in which the urce is dif- 

 fufed in a very large proportion of water. The urine of di- 

 gellion orconcoftion (urina chyli) is that evacuated two or 

 three hours after a meal. Its colour and ether urinous pro- 

 perties arc more ftrongly marked than in the preceding ; 

 but it is not yet perfedl urine. It is affected by the nature 

 •f the food. The urine of the blood (urina fanguinis) is 



voided feven or eight hours after eating, or in the morniiig 

 after a night's flcep. It is highly coloured and acrid, has 

 a ftrong tafte and fmell, not that imparted by any particular 

 food, bot the peculiar urinous odour. The circumftances 

 of digeftion and the nature of the food either do not affeft 

 this, or afTed it in a much lefs degree. It contains a large 

 proportion of falls and nr^e. It's charaaers, in fliort, are 

 thofe defcribed as belonging to urine; and it is always felef'cd 

 for the purpofe of experiments on the chemical conftitution 

 of this fluid. 



The paflfiuns have an influence on the nature of this fluid ; 

 fear, forrow, and, in general, tlie emotions which a6t vio- 

 lently on the frame, often caufc an abundant flow of colour- 

 lefs and inodorous urine, which feems to confift almoft 

 entirely of water. 



But the effects of the caufes which we have ju 11 confidered; 

 are very flight in comparifon with the changes produced by 

 difeafe. The alteration in this cafe goes deeper, and the 

 variations are more numerous and charafterillic. Since the 

 earliell ages of medicine, phylicians have drawn iudications 

 from this fource concerning the nature, progrefs, and ter- 

 mination of dileafes ; and empirics have no; overlooked fo 

 favourable an opportunityof levying a t,ix on public credulity. 

 Careful analyfes of the various morbid urines are ftill attiong 

 thofe defiderata, which promifc very interefting refults to the 

 phyliologift and pathdogill. A few fadts only have been 

 collected on this fubjeft. The fedimcnt of the urine, at 

 the termination of acute difeafcs, has been found to confift 

 chiefly of uric acid. The colourlefs fluid voided in nervous 

 diforders, in hyfteric paroxyfms, &c. is little more than 

 mere water. Phofphoric acid and phofphate of lime are 

 not found in the urine during the paroxyfm of gout ; but 

 the latter returns towards its celTation, and is even more 

 abundant than in the healthy ftate. In thofe affeCtions, in 

 which the bones become foftened, the urine has a large 

 proportion of phofphate of lime : the earth abforbed from 

 the bones is evacuated by the kidnies. During utero-gefta- 

 tion, this earthy fait is not found in the urine. For the re- 

 markable qualities of this fluid in diabetes, fee that article. 

 The fecretions of the mucous membranes, over which the 

 urine pafles, may varioufly modify its properties ; and dif- 

 eafes of thefe parts may occafion the admixture of blood, 

 pus, mucus, &c. 



The latt circumilance we have to mention concerning the 

 urinary fecretion, dilUnguiflics it from all others ; ria. that 

 the fecreted fluid is concerned in no oiher funftion, but is 

 entirely expelled from the body, after traverfmg the urinary 

 padages. In other inllances the fecreted fluids ferve fome 

 office ; the tears lubricate the furface of the eye ; the action 

 of the faliva in aflifting maftication is- very important ; the 

 bile and pancreatic juice concur in digellion. Hence the 

 alterations in the quantity or qualities of thefe are followed 

 by ferious confequences ; while the changes of the urine, 

 particularly in quantity, are hardly obfervcd. 



The /-cnij/ fa/y«/fj ( capfulx fuprarenales, or atralil?.ri:c, 

 rencs luccenturiati) are two fmail bodies, a right and a loft, 

 placed above the upper extremities of the kidnies, which 

 they cover to a certain extent, and behind the peritoneum. 

 They are fometimes double on one or holh tides. Theic 

 fize varies much according to the age of the fubj;dt : in the 

 firft months of fcetal exillence they are at leaft as large 

 as the kidnies, and they continue to grow until the firil years 

 afterbirth: but as this growth is much lefs rapid than that 

 of the kidney, the proportionate lizrs of the two organs are 

 foon entirely changed, and become fuch as we lind them in 

 the adult. When they have acquired tlieir ^reatcft magni.* 

 tude, they fometinies prefcrve il in the adult ; . or they ara 



gradually 



