APPENDIX TO CHAPTER V 165 



leaflets, melting at 150 (155), not very soluble in cold alcohol, and 

 less in water and particularly in dilute nitric acid. The picrate 

 G,H 7 N 8 . C 6 H 3 O 7 N 3 , m.p. 201-5, crystallises in two modifications ac- 

 cording to Gulewitsch [1906] and is more soluble than guani- 

 dine picrate. 



The picrolonate, C 2 H 7 N 3 . C 10 H 7 O 5 N 4 , dissolves in 4000 parts of cold 

 water; m.p. 291 (Wheeler and Jamieson [1907]). The aurichloride 

 C 2 H 7 N 3 . HAuCl 4> m.p. 198, is soluble in ether. The platinichloride 

 (C 2 H 7 N 3 ) 2 . H 2 PtCl forms monoclinic prisms and dissolves in 14^3 parts 

 of water at 18-19. 



Benzene-sulphonyl-methyl-guanidine, C 2 H 6 N 3 . SO 2 . C 6 H 5 , m.p. 184, 

 soluble in 2500 parts of cold water, is suitable for the isolation (Acker- 

 mann [1906]). Aqueous mercuric chloride does not precipitate the 

 nitrate of methylguanidine even in 5 per cent, solution ; mercuric 

 sulphate precipitates a I per cent, solution, phosphotungstic acid a 

 solution of i 19000 (Demjanowski [1912]). 



Dimethylguanidine. 



The aurichloride, C 3 H 9 N 3 . HAuCl 4 , melts at 144, decomposes at 

 150 and forms thin leaflets or plates. 



The picrolonate, C 3 H 9 N 3 . C 10 H 7 O 5 N 4 , m.p. 275-278, was probably 

 obtained from human urine by Kutscher and Lohmann [1906, 3, 4] 

 and forms four-sided prisms. The picrate, C 3 H 9 N 3 . C 6 H 3 O 7 N 3 , forms 

 small pointed needles or branch-like growths ; m.p. 224 (Wheeler and 

 Jamieson [1907]). 



