THE HAMILTON ASSOCIATION. I9 



that violent effervescing of the water marked the rapid evolution of 

 a gas, the overwhelming odor of which enforced attention to its 

 presence, and which on the application of a match burned with a 

 smoky but luminous flame and numerous explosions. It was acety- 

 lene gas. 



To Willson is due the credit of discovering how to make cal- 

 cium carbide at the price of about one cent a pound in unlimited 

 quantities instead of the rare laboratory product obtained in grains 

 at the rate of about $10,000 per pound, thus producing not only a 

 new light, but for manufacturing and commercial purposes opened 

 up a vast range of new combinations of hydro-carbons at a much 

 cheaper rate than ever existed before. The dream of the chemist 

 has been realized, and synthetic chemistry took several strides for- 

 ward. The possibilities of cheap carbide for light or chemical com- 

 binations places Willson in the front rank of the scientific men of 

 the age. 



Calcium carbide Ca C2 is described as a dark brown, dense sub- 

 stance, having a crystalline metallic fracture of blue or brown appear- 

 ance, with a specific gravity of 2.262. In a dry atmosphere it is 

 odorless, but in a moist atmosphere it emits a peculiar smell, resem- 

 bling garlic or phosphorus. When exposed to air in lumps it absorbs 

 moisture and the surface becomes coated with a layer of hydrate of 

 lime, which to a certain extent protects the rest of the substance 

 from further deterioration. It is not inflammable and may be ex- 

 posed to the temperature of a blast furnace without taking fire, the 

 exterior only being converted into lime. When brought into contact 

 with water or its vapors at ordinary temperatures it rapidly decom- 

 poses, one pound when pure generating 5,892 cubic feet of acetylene 

 gas at a temperature of 64" F. 



Calcium carbide is manufactured from powdered lime and car- 

 bon in the shape of ground coal, coke, peat or charcoal, these two 

 substances being fused together in an electric furnace. The process 

 is very simple, and may be described, thus : 



The lime and carbon, having been ground to a fine powder, is 

 intimately mixed in a certain proportion and fed into a crucible or 

 furnace, the lower part of which has a carbon plate which is attached 

 to one of the dynamo terminals ; the other terminal is connected to 

 an upright carbon resenibling the upper carbon of an arc lamp, but 



