1862.] 125 



membrane. A slow evolution of spontaneously inflammable gas, 

 burning with a splendid green flame, was also noticed ; and this evo- 

 lution of gas became more rapid when the warmth of the hand was 

 applied to the flask containing the ingredients. Purified and sub- 

 mitted to analysis, the gas exhibited a composition agreeing with the 



formula 



C 2 H 3 



Boric methide is produced from boracic ether and zincmethyl by the 

 following reaction : 



Boracic ether. Zincmethyl. Boric methide. Ethylate of zinc. 



The formation of boric methide under these circumstances proves 

 conclusively that the corresponding ethyl compound is formed, not 

 by the removal of the whole of the oxygen from boracic ether, but 

 by the actual substitution of the three atoms of oxygen in boracic 

 acid by three atoms of ethyl ; whilst boric methide is in like manner 

 produced by the similar substitution of methyl for oxygen, which is 

 quite in harmony with the mode of formation of very numerous com- 

 pounds in the organo- metallic family. 



Boric methide exists at ordinary temperatures as a colourless and 

 transparent gas possessing a peculiar and intolerably pungent odour, 

 irritating the mucous membrane arid provoking a copious flow of 

 tears. Its specific gravity is 1*93137. It retains its gaseous con- 

 dition when exposed to a cold of 16 Cent. ; but at 10 Cent., and 

 under a pressure of three atmospheres, it condenses to a colourless, 

 transparent, and very mobile liquid. It is very sparingly soluble in 

 water, but very soluble in alcohol and in ether. In contact with 

 atmospheric air, it takes fire spontaneously, burning with a bright 

 green flame, which is very fuliginous if the volume of the flame be con- 

 siderable. If the gas issue into the air through a tube ^th of an inch 

 in diameter, the amount of smoke is surprisingly great ; 2 or 3 cubic 

 inches of gas, when consumed in this way, filling the atmosphere of a 

 large room with large comet-like flocks of carbonaceous matter. This 

 curious phenomenon is probably due, in part at least, to the forma- 



