LEUCOMAi'NS OF THE URINE. 463 



periments they ascribe to lack of oxygen and to increase of carbonic 

 acid. On the other hand Formanek explains the presence of 

 ammonia as due to external decompositions and the fatal results as 

 due to the combined effects of ammonia and carbonic acid. 



The most recent contribution on this subject is that of Sanarelli 

 and Biffi.' These investigators demonstrate that many intestinal 

 products may be absorbed and subsequently be eliminated by the 

 lungs. When rectal injections of ammonia, hydrogen sulpnid, 

 butyric acid, aceton, and carbonic acid were made these substances 

 could be detected in the exhaled air. 



Sewer air, according to observations made by Odling, contains a 

 basic substance which is probably a compound ammonia. It contains, 

 however, more carbon than methylamin and less than ethylamin. 



It should be remarked that Jackson (1887) announced the pres- 

 ence in expired air of quantities of carbon monoxid gas sufficient to 

 produce the ill effects ordinarily attributed to the organic matter. 

 The presence of this poisonous gas must first be fully demonstrated 

 before it can be taken into account in the consideration of the tox- 

 icity of air ; certainly, even if present, it cannot explain the results 

 obtained by the French investigators as stated above. 



According to Ilosva, expired air contains nitrous acid. This may 

 possibly be derived from that which is constantly being formed in 

 the mouthj either by the reduction of nitrates (Miller) or by surface 

 action. 



Leucomains of the Urine. 



A number of basic substances have been isolated at different times 

 from the urine, and on that account they may be properly classed as 

 leucomains. Thus, Liebreich (1869) found in the urine a base which 

 apparently was an oxidation product of cholin, and which has since 

 been regarded as identical with betain. In 1866 Dupr6 and Bence 

 Jones found, among other things in the urine, an alkaloidal body 

 which in sulphuric acid solution possessed a blue fluorescence (see 

 p. 41). Most of the members of the purin group have been de- 

 tected in the urine and on account of their well defined nature they 

 are described by themselves. It is desirable perhaps in this connec- 

 tion to emphasize the fact already brought out (p. 405) that the 

 greater part of the purin bases found in the urine are derived from 

 the preformed bases in the food. Rachford's view that migraine is 

 due to intoxication with paraxanthin and allied bodies has been 

 referred to on page 403. 



In 1879, Thudichum announced the presence in the urine of four 

 new alkaloids, one of which, urotheobromin, was subsequently redis- 

 covered by Salomon andnamed paraxanthin. Another base which was 

 obtained, namely, reducin, yielded a barium salt which readily re- 



MmmaK d^Igime sper., 12, 90, 1902. 



