VI PREFACE. 



studies. To my colleagues of the Medical Profession 

 it will afford an easy bird's-eye view of the chemical 

 features of the field of their thoughts and action. Its 

 perusal will involve no unreasonable tax upon the time 

 of any reader or student, and occasional reference to 

 particular points is facilitated by marginal notes and a 

 short alphabetical index. 



The second part of the work is an Analytical Guide 

 for the use of those who desire to make themselves 

 practically acquainted with the phenomena and con- 

 stituents of animal bodies. It is therefore not de- 

 scriptive in the sense in which ordinary chemical text- 

 books may be said to be so, but prescriptive in the style 

 and manner of pharmacopoeias. It directs the student 

 how to proceed in order to arrive at a certain result, 

 leaving him in most cases to appreciate the result of 

 his operation by his own reflection. The guide is 

 perhaps the most elementary that could be written for 

 any practical purpose, and yet I think it improbable 

 that ordinary students of medicine will easily go 

 through the whole of its matter in the laboratory. I 

 hope, therefore, that teachers of chemistry who will 

 make use of the Guide in their classes will select the 

 reactions and analyses to be performed by each student 

 according to his knowledge, ability, and intentions. 



This little treatise summarises much of the method 



