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SCIENCE 



[N. S. Vol. XLV. No. 1172 



rapid development of inventions in this 

 line. The progress made here alone has 

 been as great as has been accomplished in 

 many individual decades in the past. The 

 importance of this is apparent when we 

 consider that if the chemical engineer had 

 at his disposal as efficient apparatus and 

 materials of construction in his plant, as 

 exist in the chemical laboratories of the 

 present day, or as the mechanical and elec- 

 trical engineers have in their work, prog- 

 ress in the arts would be at least a hundred 

 years ahead of its present development. 



The tendency to manufacture at the 

 market is another good development which 

 has been greatly accentuated by the war. 

 For some time there has been a growing 

 tendency for manufacturers who are large 

 consumers of chemicals to produce these 

 chemicals themselves. Assisted by gradual 

 price elevation, this tendency has been 

 greatly encouraged by the invention in the 

 last two decades of processes and machines 

 of merit which could find no sale as such, 

 in well-established chemical manufacturing 

 plants, because they frequently offered in- 

 sufficient advantages to warrant discard- 

 ing those already operating, or were merely 

 alternative in their character. A good ex- 

 ample of how this tendency to manufacture 

 at the market works out normally where 

 the impelling force is merely gradually ad- 

 vancing prices, competition preventing ex- 

 cessive elevation, is to be seen among others 

 in the case of bleach for paper manufactur- 

 ing. Consumers of alkali and bleach, such 

 as progressive paper manufacturers, opera- 

 ting on a large scale, and others have ex- 

 perimented for years with inventions for 

 the electrolytic production of these mate- 

 rials from common salt. Our present high 

 development in this branch of chemical in- 

 dustry is in no small degree due to these 

 individual efforts, many of which during 

 the past twenty years have been eminently 

 successful. High prices and poor deliver- 



ies in the last two years have forced mat- 

 ters to a head in this direction. Where 

 formerly we had a few large chemical 

 plants manufacturing caustic soda and 

 chlorine for bleach by electro-chemical 

 means, we now have distributed throughout 

 the country a great number of concerns 

 who have added to their equipment a plant 

 for the production of these products. The 

 operation of these units under widely di- 

 verse conditions will greatly enrich our 

 chemical engineering experience. A num- 

 ber of cell types are obtainable which op- 

 erate economically. Some of these are well 

 advertised in the current literature, but 

 some, though equally successful, such as the 

 Allen-Moore, Gibbs and Nelson cells are not 

 so well known. The cell portion of such a 

 plant is only a fraction, however, of the 

 equipment required and it is important 

 that the rest of the plant should be 

 properly designed. The simpler and more 

 durable, therefore, the design of appa- 

 ratus, the more satisfactory the entire 

 equipment will be. There has been placed 

 in operation in some eight plants recently 

 a total of nearly 2,000 cells of one type 

 alone, with a daily capacity of 200,000 

 pounds of chlorine gas. Some plants con- 

 structed this year cost as much as a half 

 million dollars. These will be valuable for 

 defense, for we use much chlorine in ma- 

 king guncotton or nitro-cellulose, for mines 

 and smokeless powder. 



This use of alternative inventions is valu- 

 able in encouraging new invention and 

 much industrial chemical investigation, and 

 alleviates to some extent the ill effects of 

 unwarranted increase in selling prices. 



Progress in Chemical Engineering may 

 be illustrated perhaps best by the progress 

 in acid-making equipment. High pressure 

 manufacturing of chemicals and difficulty 

 of obtaining supplies has brought rapid 

 improvements and development of chemical 

 engineering materials by compelling large 



