LIST OF ILLUSTRATIONS 



PAGE 



ALEXANDER SMITH Frontispiece 



Alexander Smith; B. Sc., Edinburgh, 1886; LL. D., 1919; Ph. D., 

 Munich, 1889. Fellow of the Royal Society of Edinburgh; 

 Member of the National Academy of Sciences; recently Head of the 

 Department of Chemistry, Columbia University, New York City. 



JOSEPH PRIESTLEY 28 



Joseph Priestley (1733-1804) was a nonconformist minister of 

 Birmingham, England, but devoted his leisure and his means to 

 chemical research, the results of which were published in his six 

 volumes on "Experiments and Observations on Different Kinds of 

 Air." He was the first to prepare pure oxygen, wJiich he called 

 "dephlogisticated air." He also made nitrous oxide, nitric oxide, 

 ammonia, hydrochloric acid, sulphur dioxide, and silicon fluoride. 

 He found that water could be made to absorb carbon dioxide 

 under pressure, thus laying the foundation of the "soda-water" 

 industry. On account of his sympathy with the French Revolu- 

 tion and his heterodox theological views a mob burned his home 

 and laboratory, July 14, 1791. Priestley narrowly escaped with 

 his life and went to America, where he settled at Northumberland, 

 Pennsylvania. Here a group of chemists gathered on August 1, 

 1874, to celebrate the centenary of the discovery of oxygen, and 

 founded the American Chemical Society, now the largest scientific 

 association in the world. 



ANTOINE LAURENT LAVOISIER 29 



Antoine Laurent Lavoisier (1743-1794) is called "the father of 

 modern chemistry" because he placed the science on the solid 

 basis of quantitative experiments and devised the system of naming 

 compounds by their composition. He proved that the air con- 

 tained two gases; one which was inert and another which supported 

 combustion and united with metals. He called the former gas 

 "azote" because it would not support life and the latter "oxygen" 

 because it formed acids. He was guillotined during the Reign of 

 Terror. The Commission on Weights and Measures petitioned 

 that he might be allowed to complete his work on the metric system, 

 but Coffinhal, vice-president of the revolutionary tribunal, refused, 

 saying: "The republic has no need for savants." 



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