CHEMISTRY. 159 



Elements. 



The bodies which we at present call chemical ele- 

 ments are probably all compounds. 



Chemical Union. 



It has been admitted as an axiom in chemistry, 

 that chemical union consists in the combination of 

 the atoms of bodies with each other. 



Modes of Existence. 



Solidity, liquidity, and aeriform elasticity, are only 

 three different forms of existence of the same matter. 



Discoveries. 



Dr. Black discovered carbonic acid and latent 

 heat. 



Mr. Cavendish, hydrogen, the composition of 

 water, and nitric acid. 



Dr. Priestly, nitrous gas, the existence of ammo- 

 nia, and several of the acids, in an aerial form, and 

 oxygen gas. 



Scheele also discovered oxygen gas, azote, and 

 the composition of atmospheric air. 



Lavoisier overturned Stahl's system, and intro- 

 duced a new theory. 



Dalton, the theory of definite proportions. 



Sir. H. Davy, the metallic bases of the earths and 

 alkalies. 



Chemical Nomenclature. 



The new chemical nomenclature (commonly called 

 Lavoisier's) was sketched and delivered to the world 

 in A.D. 1787, by Lavoisier, Fourcroy, Morveau, and 

 Berthollet. The prior chemical nomenclature was 

 founded by Stahl, in 1 720, and was adapted to the 

 system of Phlogiston. 



