136 PROCEEDINGS OF THE AMERICAN ACADEMY. 



formed, which very soon becomes colored yellow, and which in all 

 probability is the mercury salt of nitromethane, 



CH2 = N-Ohg* 



II 

 O 



This white salt exists, however, only a few moments, since it is a 

 very powerful oxidizing agent capable of intra-molecular oxidation. 

 It therefor^ loses water almost instantly, 



C : N - Ohg = C : NOhg + H,0, 

 H2 II 

 O 



forming mercuric fulminate ; and since the constitution of fulminate 

 of mercury is definitely proved in the following paper to be C : NOhg, 

 it follows at the same time that the nitromethane salts must have the 

 constitution represented by the general formula 



H.,C : NOM. 



II 

 O 



An aqueous solution of sodic nitromethane (10 grams) is added 

 rapidly to a cold mercuric chloride solution (containing 16 grams 

 HgClo). After standing 15 minutes, the solution (300-500 c.cm.) is 

 heated to boiling and quickly filtered from the yellow precipitate, which 

 is then boiled out once with hot water. On cooling, a grayish white 

 heavy crystalline precipitate separates out from the filtrate. In order 

 to get rid of traces of adhering mercury, it is dissolved in dilute cya- 

 nide of potash and reprecipitated with dilute nitric acid.f In this way 

 perfectly pure fulminate of mercury is obtained, which is absolutely 

 identical in every respect with the product made in the ordinary way. 

 The yield is 1 gram to 1.6 grams pure salt from 10 grams sodic nitro- 

 methane. 



0.2221 gram substance, dried over H2'^04 in a vacuum, and dissolved 

 in dilute hydrochloric acid, with addition of KCIO3, and precipi- 

 tated with HoS, gave 0.1815 gram HgS. 



0.4005 gram substance, mixed with cupric oxide, gave 0.1248 gram 

 CO., and 0,0074 gram HoO. 



0.1968 gram substance gave 17.5 c.cm. Ng at 16° and 747 mm. 



* hg represents a half-atnm of bivalent mercury, 

 t Steiner, Ber. d. cliem. Ges., IX. 787. 



