reached. Some of the most interesting of the results thus obtained 

 have been by compounds of carbon with various elements. 

 These carbides are most of them new to chemistry and have 

 furnished some interesting as well as useful reactions. Thus the 

 carbide of calcium formed by fusing together lime and carbon in 

 the electric furnace is decomposed (as are many of these carbides) 

 by contact with water and yields acetylene. Acetylene, as you 

 doubtless know, is a highly inflammable gas having considerably 

 greater illuminating power than coal gas. Five cubic feet of 

 acetylene burnt in one hour are said to give a light equivalent to 

 that of 240 candles. One ton of calcic carbide will yield about 

 11,000 cubic feet of acetylene at a cost of about £4. Acetylene can 

 either be burnt alone, or be used for enriching coal gas. Though 

 very explosive under certain conditions there would seem to be no 

 difficulty in rendering its use reasonably free from danger. It 

 has been brought already into practical use — as the train by which 

 the President of the French Republic lately travelled, was lighted 

 by it. Certain carbides of metals are found to produce, when 

 decomposed by water, some of the true liquid petroleums, a 

 circumstance which renders probable the suggestion made many 

 years ago by Mendeleef that the petroleum deposits at Baku in 

 the neighbourhood of the Caspian Sea were derived from the 

 decomposition by water of metallic carbides deeply situated under 

 the surface of the earth. 



Another result of the electric furnace is the synthetic pro- 

 duction of alcohol directly from its elements. Acetylene made 

 from calcic carbide is transformed into ethylene and the ethylene 

 being absorbed by concentrated sulphuric acid gives sulpho- 

 vinic acid and this diluted with water and boiled gives chemically 

 pure alcohol. 



Electricity has been brought into the service of the engineer 

 by the new art of electric welding and there is perhaps no 

 branch of electrical work which possesses greater possibilities at 

 present. The ease and convenience of manipulation are as yet but 

 little known in this country, but Messrs. Lloyd, of Birmingham ; 

 Messrs, Spencer, of Newburn; and The Electric Welding Company, 

 of Pimlico ; are doing much to introduce it to the wider notice it 

 deserves. The system of electric welding is due to Professor 

 Elihu Thomson, and may concisely be described as sending a 

 current of electricity through the metal to be welded and thus 

 heating it and then forcing the heated parts together by 

 mechanical pressure. The Thomson process is highly popular in 

 America, and Mr. Dobson of Messrs. Dobson and Barlow, who 

 were probably the first to use the process in this country, states in 



