1882.] On the Excretion of Nitrogen by the Skin. 35!> 



altered, and falls to such a minimum that one can scarcely perceive 

 the increase even during greater intervals of time." 



I believe that under ordinary circumstances the excretion of 

 nitrogen by the skin is very small indeed, even in cases of gout 

 (Case D) and Bright 's disease (Case B), in which I expected to find 

 it present in larger amount. This being so I can now well under- 

 stand bow it was that Voit, Ranke, and Parkes, by their indirect 

 methods came to the conclusion that there was no such excretion, yet 

 I do not deny that under extraordinary circumstances, such as those 

 mentioned by Leube,* Deininger,"! Kaup and Jurgensen,^ Taylor,§ 

 Schottin,|| and others, crystals of urea may have been found upon the 

 skin. However, with the exception of the case of Leube there does 

 not appear sufficient evidence that adequate care was taken to ascertain 

 that the crystals found were really those of urea and not of other salts, 

 such as sodium chloride, crystals of which, as is well known, frequently 

 simulate those of other bodies. I find that Leube notices this as 

 an objection to the researches of former experimenters, and to obviate 

 it he treated the mass removed from the skin with baryta- water and 

 absolute alcohol in the usual manner, and so undoubtedly proved the 

 presence of urea. Dr. Taylor seems also to have proved the presence 

 of urea in the "saline mass" removed from the skin in a case of 

 ursemic poisoning. Owing, I presume, to the smallness of the 

 quantities obtained, none of the above-named experimenters give the 

 quantity of the saline matter, nor the amount of urea found in it, 

 with the exception of Kaup and Jurgensen, who state that they 

 obtained 8"4 grms. from the shirt worn by a choleraic patient. My 

 method of collecting the cutaneous excretion afforded me an easy 

 means of ascertaining the quantity of sodium chloride excreted, and in 

 the table will be found the quantities obtained in nine experiments. 

 In five of these the amount excreted can be compared with that of 

 soluble nitrogen, and it will be seen that the quantity of sodium 

 chloride is comparatively great, the proportion to nitrogen, which is 

 nearly constant, being as 10 : 1. In conclusion I would observe that 

 though I found nitrogen to be excreted by the skin in all cases, yet 

 the quantities are so small that I do not believe the cutaneous excretion 

 can ever act vicariously towards the renal to any appreciable extent. 

 I now submit this paper to the Society in the hope that some one 

 having more leisure and more ample resources at his command may 

 further prosecute the inquiry. 



* "Deutsches Archiv fur Klinische Medicin," Bd. vii, p. 1. 

 f Id,, Bd. vii, p. 587. 

 X Id., Bd. vi, p. 55. 

 § Op. cit. 



|| Schottra, though he failed to find nitrogen in normal sweat as already men- 

 tioned, succeeded afterwards in doing so in a case of renal disease (" Schmidt's 

 Jahrb.," Bd. 74, s. 9). 



