OF ARTS AND SCIENCES. 135 



On passing dry hydrogen chloride into a chloroform or an ethereal 

 solution of phenylisocyanide (cooled to — 15°) to which exactly one 

 molecule of alcohol has been added,* there is formed diphenyl- 

 formamidinehydrochloride, and not a trace of phenylformimido- 

 ether, 



, OC 2 H 5 f 



The same result is obtained on treating an alcoholic solution of 

 phenylisocyanide (5 grams) with a few drops of alcoholic hydrogen 

 chloride. 



Prussic acid reacts likewise with halogen hydrides, forming 

 white salt-like products. Thus Claisen and Matthews | have ob- 

 tained, by using acetic ether as a diluter, the salts 2 HXC, 3 HC1, 

 and 2 HXC, 3 HBr. 



With regard to the nature of the products formed by directly 

 passing dry hydrogen haloids into anhydrous prussic acid, there is 

 no accord in the literature, especially in the case of the product 

 obtained with hydriodic acid. The last named substance was dis- 

 covered almost simultaneously by Gal § and by Gautier,|| and the 

 formula HXC, HI confirmed by both by means of analyses. 



The description of the products obtained is however entirely dif- 

 ferent. Gal, on the one hand, describes his product as crystallizing 

 in wart-like aggregates, which are instantly decomposed by water; 

 whereas Gautier, on the other hand, states that his substance 

 crystallizes in rhombohedra, has a refreshing salty but not acid 

 taste; it is very soluble in water and in alcohol, with neutral reac- 

 tion to test paper, and crystallizes from the latter solvent without 

 decomposition. The substance is not hygroscopic, and sublimes 

 without melting at 350°-400°. 



These are, however, pretty exactly the properties of ammonium 

 iodide; hence it follows that Gautier's supposed prussic acid salt 

 was nothing else than ammonium iodide. This becomes the more 

 probable because of the fact that Gautier, in his last paper f on 

 prussic acid, describes an addition product, HXC, HI, of entirely 



* Pinner, Ber. d. chem. Ges., XVI. 354, 1644. 

 t Comstock and Clapp, Amer. Chem. Jour., XIII. 527. 

 \ Ber. d. chem. Ges., XVI. 310. 

 § Comptes Rendus, LXI. 643. 



|| Bull, de la Soc. Chim., IV. 88;. Comptes Rendus, LXI. 380. 

 TF Loc. at., XVII. 143. 



