ElvISHA MlTCHEIvI^ SCIENTIFIC SOCIETY. 11 



itic variet}" by the intense heat. Along with this are 

 to be seen crystalline masses, lustrous and dark brown- 

 ish black in color. 



These are quite hard, and break with a crystalline 

 fracture. Several eiforts at effecting- a separation from 

 the g-raphitic carbon were unsuccessful. The lustre is 

 slowly lost on exposure to air, more rapidly if the air 

 be filled with moisture. The work will finally crum- 

 ble down into a gray powder with particles of black 

 graphite interspersed through it. The carbide can be 

 kept for a year or two if placed in a tightly stoppered 

 bottle and is quite easily preserved if a little coal-oil is 

 placed in the vessel containing it. 



B}^ far the most interesting property of this carbide 

 is its decomposition when brought in eontact with 

 water. The metallic carbides seem to be distinguished 

 by the ease with which 'they exchange their carbon for 

 the oxygen of water or for the radicals of various acids, 

 the carbon combining with the h3^drogen to form var- 

 ious hydrocarbons. Several authors have reported that 

 the decomposition of this particular hydrocarbon caused 

 the formation of acetylene. Experiments were carried 

 out by us proving this fact, some time before there 

 were any publications concerning it in the chemical 

 journals, but we were not at liberty to publish any- 

 thing concerning- it at that time. If the gas, as evolved, 

 is passed through a set of absorption flasks containing 

 ammoniacal copper solution it will be entirely absorbed, 

 not a bubble passing through, out of one or two liters 

 of gas. Thus it seems to be pure acetylene. The 

 amount of gas yielded by an}" one sample will be 

 affected to some extent by the amount'of- graphitic 

 carbon present. Hence different lots will vary some- 



