Manchester Memoirs, Vol. lix. ( 1 9 1 5 ), No. 11. 21 



non-metallic. After having verified the truth of this 

 hypothesis in the case of sulphur, carbon, phosphorus, etc., 

 he set himself the problem of finding out what substance 

 was produced by the combustion of inflammable air 

 (hydrogen). He expected the production of an acid. After 

 long researches in collaboration with LAPLACE, he an- 

 nounced to the Academy on the 25th of June, 1783, that 

 the substance produced by the combustion of hydrogen 

 and oxygen was water. This discovery, however, had 

 already been made by CAVENDISH. It is to be regretted 

 that Lavoisier has not done justice to the works of 

 Cavendish and other men of science. 9 



Lavoisier's discoveries, and above all the admirable 

 quantitative method which he inaugurated, opened up for 

 chemistry a new highway of discovery. Chemists in ever 

 greater numbers began to tread this highway, continuing 

 and extending the work of the pioneer, and in the course 

 of the 19th century chemistry underwent unprecedented 

 development. 



To understand the historical influence of the creator 

 of modern chemistry, one has only to call to mind the 

 innumerable applications of chemistry, from chemical 

 matches and photography to the chemical industry, 

 properly so called. This industry furnishes us with in- 

 numerable products, the economic importance of which 

 is enormous, because, in an infinite number of cases, they 

 transform products of little value into valuable substances, 

 and furnishes to a crowd of other industries products 

 indispensable to them. Among the many applications of 

 chemistry we need only cite the employment of chemical 



,J Writing to Joseph Priestley in April, 1783, with reference to some 

 of Priestley's experiments, J AMES Watt suggests the theory that water is 

 composed of dephlogisticaled air and phlogiston deprived of part of their 

 latent or elementary heat {Encyclopaedia Britannica, 11th edition, vol. 28 

 [1911], p. 417)- 



