454 APPENDIX. 



acid fluid of the spleen* and in leuceemic blood. f Further, 

 very large quantities of this acid have been obtained, under my 

 own inspection, from normal human sweat, the exact nature of the 

 acid being not only determined by the reactions described in p. 50, 

 but also by the determination of its saturating capacity and by 

 elementary analysis. 



(4) Addition to p. 56, line 8 from bottom. Schottin believes 

 that he has found metacetonic acid in the sweat ; but considering 

 the small quantities in which the acid in question occurs, and that 

 formic, acetic, and butyric acids are also present, it must remain 

 undecided whether this supposed metacetonic acid may not be 

 merely a mixture of the two last-named acids. 



(5) Addition to p. 61, line 5. Schottin has determined the 

 existence of butyric acid in the sweat with all the necessary 

 accuracy, his investigations having been carried on under my own 

 superintendence. Its quantity was, however, far less than that of 

 the acetic and formic acids. It is, moreover, not a mere product 

 of decomposition of the secretion of the sebaceous follicles, as I 

 formerly believed, but occurs in a free state in the sweat of the 

 axillary regions, the genitals, and the feet. 



(6) Addition to p. 89, line 17. StreckerJ has discovered a body 

 of much interest, which is isomeric with lactamide. He has termed 

 it alanine ; its formula is C 6 H 7 NO 4 ; and it is prepared in the 

 following manner : 



If a mixture of 2 parts of aldehyde-ammonia and 1 part of 

 anhydrous prussic acid be heated with an excess of aqueous hydro- 

 chloric acid, this substance is formed ; it must be precipitated 

 from the hydrochlorate of ammonia which is intermingled with 

 it, partly by crystallisation, and partly by extraction with alcohol 

 and ether; the hydrochloric-acid compound is decomposed by 

 hydrated oxide of lead (C 4 H 4 O 2 + C 2 NH + 2 HO = C 6 H 7 NO 4 ). 



Alanine crystallises in nacreous, oblique rhombic prisms, or in 

 needles united in tufts; it dissolves in 4 '6 parts of water at 17, 

 is slightly soluble in cold alcohol, but insoluble in ether; the 

 aqueous solution has an intensely sweet taste, does not re-act on 

 vegetable colours, and is precipitated by no re-agent. It sublimes 



* Verhandl. d. phys.-med. Ges. in Wurzb. Bd. 2, S. 298. 



* Ibid. p. 321. 



t Ann. d. Ch. u. Pharm. Bd. 75, S. 27-40. 



