. PIQGRAPHIES OF SCIENTIFIC MEN 



. t :: , : t -The doctrines -of Aristotle, and Byzantine, Egyptian, 

 Arabian,' and European writers concerning the "four 

 elements" earth, water, fire, and air and other non- 

 scientific theories were swept away by the master-mind 

 of the great Frenchman. Even Priestley, Cavendish, 

 Scheele, Macquer, and other distinguished men could not 

 entirely divest themselves of the phlogistic theory ; in 

 fact, Black "was the only chemist of his age who com- 

 pletely and openly avowed his conversion to the new 

 Lavoisierian doctrine of combustion." 



In 1764 Lavoisier (having been called to the bar as an 

 avocat) gained the prize awarded by the Government of 

 Louis XV. for the best method of lighting the streets of 

 Paris and other large towns, and elaborate experiments 

 on the subject are to be found in the memoirs of the 

 Acade'mie des Sciences " the greatest scientific body on 

 earth " as the illustrious Academy has been called by a 

 distinguished American writer; and in 1768 Lavoisier 

 was elected one of its members. Between that date and 

 1774 he published many papers on chemical, mathematical, 

 and geological subjects all of which are remarkable for 

 showing the extraordinary ardour and devotion to science 

 of this truly great philosopher. The accuracy of his work 

 and reasoning powers will be found by referring to two 

 of his papers in the memoirs of the Academy for 1770, 

 in which he refutes the idea, held by many, that water 

 could be converted into earth ; and it is remarkable that 



