38 A CHEMICAL TRIAD. 



Lavoisier in his own way. He revolutionised the whole do- 

 mains of chemistry ; he reduced the nomenclature of that 

 science to a system, and gave us most of the names by which 

 chemical substances are at the present time known. 



f l shall not wait longer for Priestley,' at length said 

 Lavoisier ; * I am impatient to show you my experiment :' 

 and, saying this, he made arrangements for burning a piece 

 of iron wire in oxygen gas. Every itinerant chemical lecturer 

 performs the experiment now, because it is so brilliant. The 

 performance of it by Lavoisier, in the presence of his friend 

 Berthollet, marked the downfall of a theory. It was one of 

 the capital discoveries of Lavoisier, that when a body was 

 burned and the results of combustion collected, they were 

 invariably heavier than the body consumed ; from which it is 

 quite clear that combustion cannot depend upon the loss of a 

 something which philosophers called ' phlogiston,' but that it 

 is attended with the gain of something. So Lavoisier pro- 

 ceeded to weigh his iron wire ; he then burned it, and weighed 

 the result of combustion ; no difficult matter in this case, in- 

 asmuch as that result is a solid. 



1 shall not entrap the reader against his knowledge, 

 giving him a chemical lecture in the place of a biographical 

 incident; but it will be at least worth while to make him 

 aware of some of the great points of philosophy developed 

 by the subject of this sketch. 



Whilst Lavoisier and Berthollet were thus engaged, the 

 bell rang, and immediately afterwards Priestley was intro- 

 duced. 



6 Mon ami,' said Lavoisier, going to meet him, and grasp- 

 ing his hand, ' why so late T 



Priestley trembled, and was pale ; his coat, too, was torn ; 

 lie sank into a chair, and for a time could find no words. 

 When at last he spoke, Priestley explained that he had 

 been lost in a crowd of revolutionary miscreants, who were 

 parading the streets with a model of the guillotine. Such 



