PREFACE. 



BY the application to Chemistry of the meth- 

 ods which had for centuries been followed by 

 philosophers in ascertaining the causes of natu- 

 ral phenomena in physics, by the observation 

 of weight and measure, LAVOISIER laid the 

 foundation of a new science, which, having 

 been cultivated by a host of distinguished men, 

 has, in a singularly short period, reached a high 

 degree of perfection. 



It was the investigation and determination of 

 all the conditions which are essential to an ob- 

 servation or an experiment, and the discovery 

 of the true principles of scientific research, that 

 protected chemists from error, and conducted 

 them, by a way equally simple and secure, to 

 discoveries which have shed a brilliant light on 

 those natural phenomena, which were previous- 

 ly the most obscure and incomprehensible. 



The most useful applications to the arts, to 

 industry, and to all branches of knowledge re- 

 lated to chemistry, sprung from the laws thus 



