THE URINE. 389 



products of the exchange of material; still, often a smaller or 

 greater part of the body in question withdraws itself from oxidation 

 and appears unchanged in the urine. A part of the organic acids, 

 which are otherwise burnt into 1 water and carbonates and render 

 the urine neutral or alkaline act in this way. The volatile fatty 

 acids poor in carbon are less easily burnt than those rich in carbon, 

 and they therefore pass in large amounts unchanged into the urine. 

 This is especially true of formic and acetic acids (SCHOTTEN, 

 GREHAKT and QUINQUAND). Oxalic acid passes completely or 

 almost completely unchanged into the urine (GAGLIO). 



The acid amides appear not to be changed in the body 

 (SCHULTZEN and NENCKI). A small part of the amido-acids seem 

 indeed to be eliminated unchanged, but otherwise they are, as stated 

 above (page 338) for leucin, glycocoll and aspartic acid, decomposed 

 within the body, and they may therefore cause an increased elimi- 

 nation of urea. Sarcosin (methylglycocoll), NH(CH 3 ).CH 2 .COOH, 

 also perhaps passes in small part into the corresponding uramido- 

 acid, methylhydantoinic acid, NPI 2 .CO.N(CH 3 ).CH 2 .COOH. Also 

 taurin, amido-ethylsulphonic acid, which acts somewhat differently 

 in different animals (SALKOWSKI), passes in human beings, at least 

 in part, into the corresponding uramido-acid, taurocarbaminic acid, 

 NH 2 .CO.NH.C 2 H 4 .S0 2 .OH. A part of the taurin appears as such 

 in the urine. In rabbits, when taurin is introduced into the 

 stomach, nearly all its sulphur appears in the urine as sulphuric and 

 sulphurous acids. After subcutaneous injection the taurin appears 

 again in great part unchanged in the urine. 



Creatin passes, at least in part, into creatinin. A part may perhaps 

 appear as urea (see page 257). Hypoxanthin passes into uric acid. 



A coupling with glycocoll may also occur. Furfur ol or the 

 anhydride of pyromucic acid, C 5 H 4 2 , passes to a great extent 

 coupled with glycocoll as pyromucuric acid, C 7 H 7 N 4 0, into the urine 

 of rabbits and dogs and to a less extent as furfuracrylic acid 

 coupled with glycocoll as furfuracryluric acid, CsH^O (JAFFE 

 and COHN). In birds (hens) this condition is different. In these 

 animals furfurol gives pyromucic acid and a coupled acid, 

 pyromucinornithuric acid, C 15 H 16 N 2 6 , which decomposes on warm- 

 ing with concentrated hydrochloric acid into pyromucic acid and 

 ornithin, C 6 H 12 N 2 2 (JAFFE and COHN). 



