INTRODUCTION. XI 



veries, chemists will be probably obliged to 

 trace back the road of error which they have so 

 long traversed, in order to learn afresh the first 

 principles of their art/* 



It is greatly to be lamented that the pursuits 

 of the chemists, instead of being confined to 

 their proper objects to the examination of the 

 qualities of matter, dead and common have 

 been equally, but improperly, directed and ex- 

 tended to the investigation of living matter also ; 

 hoping to explore the causes of animation, and 

 of vital action, from chemical phenomena, which 

 are the inevitable attributes of decomposition 

 and decay.* 



* The Monthly Magazine, some time since, very justly 

 observed, " that Dr. DAVY'S Chemical Lectures shew, that 

 students in chemistry have to unlearn most of what they have 

 received as authority in that science. It may be hoped, there- 

 fore, that we shall have no other voluminous systems of this 

 variable science > till its elementary principles are somewhat 

 better settled " 



* In deprecating, as I do, experiments, it is proper that I 

 should be clearly understood. I deprecate the application of 

 chemistry to physiology, as much as I would deprecate the 

 practice of employing the phenomena of death,^in order to 

 explain the actions of life ; and more especially I deprecate 

 the experiments made on different organs and fluids of the 

 living system, because the natural and healthy functions of a 

 part can never be ascertained through the medium of mutila- 

 tion, or extirpation; but%ith respect to the investigation of 

 matter dead and common, experiment alone is the medium 



