August 7, 1914] 



SCIENCE 



189 



condition, it is an aqueous solution, con- 

 taining only about one third of real acid, 

 so that the transportation of one ton of 

 acid practically involves the extra cost of 

 freight of about two tons of water. Fur- 

 thermore, the transportation of hydro- 

 chloric acid in anything but glass carboys 

 involves very difScult problems in itself, 

 so that the market for hydrochloric acid 

 remains always within a relatively small 

 zone from its point of production. How- 

 ever, for awhile at least, an outlet for this 

 hydrochloric acid was found by converting 

 it into a dry material which can easily be 

 transported; namely, chloride of lime or 

 bleaching-powder. 



The amount of bleaching-powder con- 

 sumed in the world practically dictated the 

 limited extent to which the Leblanc proc- 

 ess could be profitably worked in competi- 

 tion with the Solvay process. But even 

 this outlet has been blocked during these 

 later years by the advent of the electrolytic 

 alkali processes, which have sprung up 

 successfully in several countries, and which 

 give as a cheap by-product, chlorine, which 

 is directly converted into chloride of lime. 



To-day, any process which involves the 

 production of large quantities of hydro- 

 chloric acid, beyond what the market can 

 absorb as such, or as derivatives thereof, 

 becomes a positive detriment, and foretells 

 failure of the process. Even if we could 

 afford to lose all the acid, the disposal of 

 large quantities thereof conflicts imme- 

 diately with laws and ordinances relative 

 to the pollution of the atmosphere or 

 streams, or the rights of neighbors, and 

 occasions expensive damage suits. 



Whatever is said about hydrochloric 

 acid applies to some extent to chlorine, pro- 

 duced in the electrolytic manufacture of 

 caustic soda. Here again, the develop- 

 ment of the latter industry is limited, 

 primarily, by the amount of chlorine which 



the market, as such, or as chlorinated 

 products, can absorb. 



At any rate, chlorine can be produced 

 so much cheaper by electrolytic caustic 

 alkali processes than formerly, and in the 

 meantime the market price of chloride of 

 lime has already been cut about in half. 



In as far as the rather young electrolytic 

 alkali industry has taken a considerable 

 development in the United States, let us 

 examine it somewhat nearer. 



At present, the world's production of 

 chloride of lime approximates about half 

 a million tons. 



"We used to import all our chloride of 

 lime from Europe, until about fifteen years 

 ago, when the firet successful electrolytic 

 alkali works were started at Niagara Palls. 

 That ingenious mercury cell of Hamilton 

 Y. Castner — a pupil of Professor Chandler 

 and one of the illustrious sons of the 

 Columbia School of Mines — ^was first used, 

 and his process still furnishes a large part 

 of all the electrolytic caustic soda and 

 chlorine manufactured here and abroad. 



At present, about 30,000 electrical horse- 

 power are employed uninterruptedly for 

 the different processes used in the United 

 States, and our home production has in- 

 creased to the point where, instead of im- 

 porting chloride of Hme, we shall soon be 

 compelled to export our surplus production. 



It looks now as if, for the moment at 

 least, any sudden considerable increase in 

 the production of chloride of lime would 

 lead to over-production until new channels 

 of consumption of chloride of lime or other 

 chlorine products can be found. 



However, new uses for chlorine are being 

 found every day. The very fact that com- 

 mercial hydrochloric acid of exceptional 

 purity is now being manufactured in Niag- 

 ara Falls by starting from chlorine, indi- 

 cates clearly that conditions are being 

 reversed; no longer than a few years ago, 



