the Knowledge of the Tetrazoline Group. 211 



This explanation of the phenomenon is supported by the fact that 

 the alcoholic mother liquor of the crystals of tetrazoline hydro- 

 chloride yields the yellow additive compound, and that aqueous 

 solutions of the normal pi atini chloride slowly deposit the insoluble 

 substance (C 2 H 4 N 4 ) 2 , PtCl 4 . 



We have begun already to study, on similar lines, dimethyl- 

 tetrazoline which is formed by the action of heat on mono- 

 acetyl hydrazine (see Pellizzari, Atti R. Accad. Lincei, 1899 [v], 

 8, 327). The properties of this base differ in many respects from 

 tetrazoline ; whilst the latter yields with mercuric chloride the 

 compound 2C 2 H 4 N 4 , 3HgCl 2 , dimethyltetrazoline forms with the 

 metallic chloride the additive product C 4 H 8 N 4 , HgCl 2 . Aldehydes 

 which so readily condense with tetrazoline, have no action on 

 dimethyltetrazoline. On the other hand, platinic chloride yields 

 with dimethyltetrazoline a very soluble normal platinichloride 

 (C 4 H 8 N 4 ) 2 , H 2 PtCl 6 ; its aqueous solution, on standing, slowly 

 deposits a }^ellow solid which has the composition (C 4 H 8 N 4 ) 2 , PtCl 4 

 and, therefore, is analogous to the additive product of the metallic 

 chloride with tetrazoline. Methyl iodide, also, seems to react with 

 dimethyltetrazoline in a similar manner as with tetrazoline, and 

 yields a substance, crystallising in brown needles, which resembles 

 in properties the compound C 3 H 7 N 4 I 3 . 



We are engaged in the further study of this substance and in 

 examining the action of aldehydes on bisdiazomethane and allied 

 heterocyclic compounds. 



