NEF. — BIVALENT CAUBON. 165 



duct is obtained which is only partially volatile, and leaves au amor- 

 phous opaque residue. This can.^ however, be seen immediately by 

 the ai)pfarauce of the lorn)ylchloridoxime itself when prepared ; if 

 the crystals are clear as glass, the substance is pure ; if, on the other 

 hand, the crystals are turbid or opaque, the product is impure. In 

 larger amounts (a few decigrams) formylchloridoxime decomposes 

 very soon at ordinary temperature ; it at first becomes colored green, 

 and then puffs up with tremendous evolution of heat and a hissing 

 noise. The same decomposition takes place instantly by the heat of 

 the hand, or on heating the substance in a vacuum at 40°. Carbon 

 monoxide is given off and the puffed up sticky residue consists chiefly 

 of hydroxylamine hydrochloride. 



The substance thus possesses a tremendous tendency to decompose 

 into hydrogen chloride and carbyloxime, C : NOH, and the latter com- 

 pound is then split by the hydrochloric acid into carbonmonoxide and 

 hydroxylamine. Formylchloridoxime possesses very poisonous prop- 

 erties, has a very sharp pungent smell, and diluted with air or in 

 dilute aqueous solution has an odor which cannot be distinguished 

 from that of prussic acid ; this is probably due to a partial dissociation 

 into hydrogen chloride and carbyloxime, C ■ NOH. Also the action 

 of the substance on the human system, producing a flow of saliva, an 

 irritation in the throat, and violent headaches, is entirely analogous to 

 that of prussic acid. Formylchloridoxime possesses also a very sharp 

 pungent smell, and acts violently on the eyes, the action is not at first 

 very noticeable, but sets in after a time. Thus, for example, after 

 being exposed to the influence of the vapor of the substance for about 

 one hour on an afternoon, my eyes were only colored intensely red, 

 but in the evening a most violent inflammation set in, so that I could 

 hardly see for twenty -four hours. The consequences, however, are 

 only temporary. 



Formylchloridoxime, when brought on the skin, causes white blis- 

 ters and deep wounds, which heal only very slowly. The substance is 

 not decomposed either by water or by alcohol, — a noteworthy prop- 

 erty for a soluble acid chloride ; in this respect it resembles the acid 

 chloride, benzenylethoximchloride, 



C6H5C = NOCoH5, 

 CI 



obtained by Tiemann and Kriiger,* which is stable even towards caus- 



* Ber. d. chem. Ges., XVIII. 732. 



