92 



alcohol and in ether, from the former of which it precipitates on 

 addition of water. Its boiling-point lies between 93 and 96 C, and 

 its specific gravity is 3*069. It thus appears to have a weight 

 greater than any known non-metallic liquid at ordinary temperature. 

 By analysis it gave numbers according with the formula 



0,H 3 Hg. 



The formation of this body is readily intelligible from the following 

 equation, if we neglect secondary decompositions, 



C 2 H s Hg 2 , I + KCy=C 2 H 3 Hg + KI + Cy + Hg. 



The cyanogen does not, however, appear as liberated gas, but 

 remains behind in the form of paracyanogen. 



From the constitution of this substance, the name mercuric methyl 

 is proposed. Should this appellation be accepted, Dr. Frankland's 

 radical would be styled mercurous methyl. 



To control the analysis, and further corroborate the formula, the 

 specific gravity of the vapour was taken after Dumas' s method. 

 It was found to be 14-86. The weight represented by the formula 

 C 2 H 3 Hg, divided by the experimental density, gives the quotient 

 7*73. Supposing the constituents of mercuric methyl condensed 

 into one volume of vapour, the number 7*23 should have been ob- 

 tained. 



The theoretical density of mercuric methyl is =15*9. It is, 



/*2o 



however, more probable that the elements of this compound are con- 

 densed into two volumes, whence the formula should be doubled to 

 (C 2 H 3 ) 2 Hg 2 . 



Mercuric methyl may also be obtained, but less readily, by em- 

 ploying hydrate of potassa or lime, instead of an alkaline cyanide. 



In this reaction much gas is liberated. 



2(C 2 H 3 Hg 2 ,I) + 2KOHO= C 2 H 3 Hg + C 2 H 4 + 3HgO + HO + 2KI. 



Mercuric methyl exhibits no tendency to unite with the electro- 

 negative elements, such as chlorine, oxygen, &c. All attempts to 

 produce such combinations lead to the destruction of the substance. 

 With iodine or bromine the liquid hisses as if hot metal were plunged 

 into water. Methyl gas is liberated, and the iodide or bromide of 

 mercurous methyl is produced: 



