36 THE LIFE OF SCIENCE 



Lastly, it is necessary to know the history of epidemics and to 

 study all the social facts that have been their causes or their re- 

 sults, to estimate correctly the evolution of medical ideas. 



2. Science and technology. Industrial requirements are always 

 putting new questions to science, and in this way they guide, so to 

 say, its evolution. On the other hand, the progress of science con- 

 tinually gives birth to new industries or brings new life to old 

 ones. It follows that the history of science is constantly inter- 

 woven with the history of technology, and that it is impossible to 

 separate one from the other. 



Let us see some examples. After exhaustion-pumps had been in- 

 vented, there was such a demand for good pumps of this kind that 

 special workshops were founded in the beginning of the eighteenth 

 century, in Leyden, Holland, to make them, and of course these 

 workshops soon undertook to make other scientific instruments. It 

 is hardly necessary to point out how intimately connected the 

 making of these instruments is with the history of physics or as- 

 tronomy. 



A geological discovery suffices to revolutionize a whole country 

 and transform an agricultural nation into an industrial one. Of 

 course, a transformation as complete as this involves a radical 

 change in scientific needs. The working of mines has always 

 exerted such a deep influence on the evolution of science and 

 civilization that one might compare the importance of mines in the 

 history of science with that of temples in the history of art. L. de 

 Launay has very clearly shown that the silver mines in Laurion 

 played a considerable part in the history of Greece. 



The history of chemistry would sometimes be unintelligible if 

 the history of chemical industries was not studied at the same 

 time. Let me simply remind the reader of the case of coloring 

 matters. Industrial research made in this direction has deeply in- 

 fluenced the progress of organic chemistry. On the other hand, it 

 is well known how much has been done to improve this industry 

 by the scientists of the German Chemical Society. 



