BEGINNINGS OF MODERN CHEMISTRY 



tering for some time, had not been completely over- 

 thrown. 



In 1787 Lavoisier, in conjunction with Guyon de 

 Morveau, Berthollet, and Fourcroy, introduced the re- 

 form in chemical nomenclature which until then had 

 remained practically unchanged since alchemical days. 

 Such expressions as " dephlogisticated " and "phlogis- 

 ticated " would obviously have little meaning to a gen- 

 eration who were no longer to believe in the existence of 

 phlogiston. It was appropriate that a revolution in 

 chemical thought should be accompanied by a corre- 

 sponding revolution in chemical names, and to Lavoi- 

 sier belongs chiefly the credit of bringing about this 

 revolution. In his Elements of Chemistry he made use 

 of this new nomenclature, and it seemed so clearly an 

 improvement over the old that the scientific world has- 

 tened to adopt it. In this connection Lavoisier says: 

 "We have, therefore, laid aside the expression metallic 

 calx altogether, and have substituted in its place the 

 word oxide. By this it may be seen that the language 

 we have adopted is both copious and expressive. The 

 first or lowest degree of oxygenation in bodies converts 

 them into oxides; a second degree of additional oxy- 

 genation constitutes the class of acids of which the spe- 

 cific names drawn from their particular bases terminate 

 in ous, as in the nitrous and the sulphurous acids. 

 The third degree of oxygenation changes these into the 

 species of acids distinguished by the termination in ic, 

 as the nitric and sulphuric acids; and, lastly, we can 

 express a fourth or higher degree of oxygenation by 

 adding the word oxygenated to the name of the acid, as 

 has already been done with oxygenated muriatic acid." 9 



33 



