444 POPULAR SCIENCE MONTHLY. 



the field of technical chemistry as possible, I could doubtless with 

 equal propriety have selected others. We can simply mention such 

 important questions as the hygienic preservation of food, the flame- 

 proofing and preservation of wood, prevention of the corrosion of 

 structural iron and steel, the great problems of chemical metallurgy, 

 et cetera. We must, however, note some of the more recently de- 

 veloped forces and phenomena of nature, the application of which to 

 technical chemistry forms problems for to-day. One of the most 

 important of these is electricity. Thanks to the triumphs of modern 

 electrical engineering we are now able to call to our aid unlimited 

 amounts of this agent at a cost comparable to that of other forms of 

 energy. Possibly the simplest, though not the earliest, method of 

 utilizing electrical energy in chemical processes is in supplying the 

 heat necessary to carry on a reaction directly at the point where the 

 reaction takes place. In a number of chemical industries, for example, 

 the manufacture of phosphorus, it was previously necessary to produce 

 within thick walled retorts a very high temperature. The result was 

 that a great deal of heat was wasted, the retorts deteriorated very 

 rapidly and the reaction was carried on at a low efficiency. By using 

 an electric furnace for the manufacture of phosphorus these expensive 

 retorts are eliminated. In addition much cheaper raw materials may 

 be used, the process is made continuous and a high efficiency obtained. 

 By the substitution of electrical heating for the closed retorts 

 previously used in the preparation of carbon bisulphide the manu- 

 facture of this chemical has been placed upon an entirely new basis. 

 The economy introduced by supplying the heat at the point where 

 the union of carbon and sulphur takes place is clearly indicated by the 

 low price at which this material can now be sold and its enormously 

 increased consumption. 



With the ability to obtain temperatures far above that which is 

 possible by the ordinary combustion of fuel there was opened up a 

 new field in synthetic chemistry. Eeactions which it was impossible 

 to carry out on a technical scale and others the existence of which 

 was not suspected are now through the application of electrical energy 

 become the bases of large manufacturing enterprises. Calcium car- 

 bide, carborundum, artificial graphite and many hitherto unknown 

 alloys are the commercial products of the electric furnace where 

 temperatures in the neighborhood of 3000° C. obtain. 



The third and more strictly chemical application of electrical 

 energy is in the use of the current for electrolysis. Faraday long ago 

 determined the laws according to which chemical compounds break up 

 when subjected to the passage of an electric current. It is only in 

 recent years, however, that the cost of electrical energy has made it 

 possible to apply the knowledge thus furnished by this great in- 



