170 PROCEEDINGS OF THE AMERICAN ACADEMY. 



taining pieces of ice, an aqueous solution of hydrogen sulphide (one 

 molecule), reaction sets in immediately, and a strong odor resembling 

 very closely that of prussic acid is noticed. The clear colorless fil- 

 trate contains both silver and sulphur ; on addition of silver nitrate, a 

 brown precipitate consisting of silver fulminate and silver sulphide 

 is obtained ; hydrochloric acid precipitates chloride and sulphide of 

 silver. On treating silver fulminate with hydrogen sulphide, an addi- 

 tion must therefore take place as follows : 



AgON : C + H^S =r AgON : C^^ , 



forming silver thioformhydroxamate, which, like silver formylchlorid- 

 oxime, is soluble in water; this salt is then further acted upon by 

 hydrogen sulphide, and partially converted into silver sulphide and 

 thioformhydroxamic acid, 



HON ; C^jj • 



The above facts suffice also to explain fully the former experiments 

 of Ehrenberg* and of Scholvien.f Scholvien believed he had ob- 

 tained free fulminic acid on adding aqueous sodic fulminate to cold 

 dilute sulphuric acid and extracting immediately with ether, for he 

 obtained by shaking the ethereal solution quickly with silver nitrate 

 a precipitate of silver fulminate. t He describes the " free fulminic 

 acid " as a volatile compound, which affects the eyes and mucous mem- 

 brane of the nose in an intolerable manner. 



It is now clear that Scholvien's compound was nothing else than 



XT 



formylsulphate-oxime, HON: Cqo/-) qtt formed by an addition of sul- 

 phuric acid to the unsaturated carbon atom present in sodic fulminate, 

 as follows : 



NaON : C -f H^SO^ = NaON : C^gQ ^^ (I.) 



2NaON : C^Q Qjj -H HaSO^^ SHONiC^g^ ^j^ + Na,S04. (H.) 



Formylsulphate-oxime is a substance which is far less stable than 

 the analogous formylchloridoxime described above, which is not sur- 

 prising. It possesses, just as formylchloridoxime, only to a far 

 greater extent, a tendency to split into sulphuric acid and carbyl- 

 oxime, C:NOH. This is the reason why Scholvien always noticed 



* Journ. f. prakt. Cliem., [2.], XXX, 43. \ Ibid., XXXIL, 463, 481. 



t Ibid., XXXII. 463, 480. 



