RELATIONS TO OTHER SCIENCES 677 



cultivation of the borderland between the sciences of physics and 

 chemistry that has been going on with increasing activity during 

 the past quarter of a century. It is safe to say that the series of 

 text-books of physical chemistry now being edited by Sir William 

 Ramsay, and of which the Phase Rule and its Application, by 

 Alex. Findlay, is the pioneer, will find their way largely into the 

 libraries of the technical chemists. Many examples may be cited 

 of the utilization of these generalizations in the solution of pro- 

 blems in technical chemistry, but Christy's : admirable researches 

 into the rationale of the cyanide processes for the recovery of gold 

 from its ores will suffice. The experience of the past has repeatedly 

 demonstrated the commercial possibilities that are latent in scien- 

 tific theories. A famous example is found in the commercial de- 

 velopment of benzene. Lachman, in 1898, after referring to its 

 discovery by Faraday in 1825, and its production from benzoic 

 acid by Mitscherlich nine years later, says : 2 " These famous chem- 

 ists little thought that their limpid oil would once lay claim to be 

 the most important substance in organic chemistry; that it would 

 give birth to untold thousands of compounds; that it would re- 

 volutionize science and technology. The technical development 

 of benzene and its derivatives employs over fifteen thousand work- 

 men in Germany alone; the commercial value of the products 

 reaches tens of millions of dollars; by far the greater portion of 

 the research work done to-day is concerned with the same group 

 of substances. Nearly all of this tremendous activity is due to a 

 single idea, advanced in a masterly treatise by August Kekule in 

 the year 1865. Twenty-five years sufficed for the chemists of all 

 nations to recognize the inestimable importance of the benzene 

 theory, for in 1890 they came together at Berlin to do honor to the 

 man who had created a new epoch in the science." There is abund- 

 ant verification of Hoffmann's statement that "the technologist 

 is not likely to leave long without utilization any fact of science 

 which may be developed and made valuable from the technical 

 side," and of Ostwald's saying "that the science of to-day is the 

 practice of to-morrow." 



In his most attractive book, Physical Chemistry in the Service 

 of the Sciences, van 't Hoff says: "There exists in Germany a 

 very beneficial cooperation between laboratory work and tech- 

 nical work. Both go as far as possible hand in hand. After phys- 

 ical chemistry had made several important advances and was 

 firmly established in such a way that pure chemistry was assisted 

 by cooperation with it, Ostwald judged correctly that this coopera- 



1 Transactions, Am. Inst. Mining Eng., vol. xxvi, p. 735, 1897, and vol. xxx, 

 p. 864, 1901. 



2 Spirit of Organic Chemistry, p. 21. 



