138 PROCEEDINGS OF THE AMERICAN ACADEMY. 



and Rilliet * is, in all probability, basic mercuric carbondioxidoxime, 



Hg; ;C:NOhg. 



A yellow compound insoluble in water is, in all cases, the chief pro- 

 duct of the action between aqueous solutions of sodic nitromethane 

 and mercuric chloride ; in fact only by the above mentioned method is 

 it possible to obtain fulminate ot mercury in ajipreciable amounts. 

 If the corrosive sublimate solution is heated, before adding the sodic 

 nitromethane solution, or if the former solution is added to the latter 

 solution, not a trace of mercuric fulminate can be isolated, and much 

 yellow insoluble mercury salt is formed. The composition of this yel- 

 low salt varies also according to whether the mercuric chloride solution 

 is added to a solution of the sodium salt, or vice versa. In the latter 

 case, the salt obtained contains much more carbon and nitrogen. 



Basic Mercuric Carbondioxidoxime, Hg C : NOhg. 



On the addition of a solution of mercuric chloride (containing 

 16 grams HgCl2) to a cold aqueous solution of sodic nitromethane 

 (10 grams), a white precipitate is formed which, after an hour's stand- 

 ing, has become perfectly yellow. The solution is decanted, and the 

 residue is repeatedly treated with boiling water, and then dried on 

 clay plates, and finally at 100°. The latter operation must be carried 

 on with all possible precautions, since it happened several times that 

 the salt exploded, demolishing the air bath and the windows of the 

 hood. The yield from 10 grams sodium salt was regularly from 

 8 to 10 grams. The salt is, at ordinary temperatures, not quite so 

 dangerous as mercuric fulminate, but it often explodes by friction. 

 It is absolutely free from chlorine and contains no hydrogen : digestion 

 with dilute sulphuric or with dilute nitric acid, in which it is insoluble, 

 does not change the composition of the salt. 



0.4698 gram, mixed with cupric oxide, gave 0.0612 gram COo and 



0.0129 gram l\0. 

 0.1818 gram, mixed with cupric oxide, gave 6.5 ccm. Ng at 19° 



and 747 mm. 

 0.2195 gram, dissolved in dilute hydrochloric acid, with addition of 



little KCIO3 and precipitated with HgS, gave 0.2045 gram HgS. 



* Ber. d. cliem. Ges., V. 1030. Cf. Ann. Chem. (Liebig), CLXXI. 35. 



