AUTHOR'S PREFACE. xv 



for an instant, doubt that pathology, therapeutics, and diag- 

 nosis, are only safely based on chemistry, physiology, and morbid 

 anatomy: he cannot entertain a doubt that the same chemistiy 

 with which he scans the changes in crude inorganic matter, 

 will likewise enable him, if not at present, yet surely at some 

 future period, to detect the variations in the composition of the 

 animal fluids and solids, some of which are dependent on phy- 

 siological, others on pathological causes, and will throw a new 

 light on the normal functions of the organism, as well as on 

 the various processes of disease. 



After contemplating the dependence of vital manifestations 

 on the unceasing metamorphosis of the animal body, and the 

 secretions and excretions as its products ; after glancing at the 

 physical and chemical modifications that these secretions and 

 excretions undergo in numerous pathological conditions, and 

 observing how these changes aflfect the structure and chemical 

 conditions of the different organs, we can no longer entertain 

 a doubt that all morbid phenomena are accompanied by me- 

 tamorphoses in the organism, different from those that occur 

 in the normal condition. But it will require an immense number 

 of analyses in order to ascertain and determine these modifi- 

 cations, to express them in definite terms, to connect them 

 duly with functional disturbances in the organism, or with 

 other symptomatic phenomena ; and, finally, as far as possible, 

 to endeavour to discover their origin. In such researches 

 the mere chemist can do little : in order to produce results really 

 serviceable to science, physiology and pathology are as essential 

 as chemistry itself, and no one can hope to advance this de- 

 partment of scientific inquiry who does not include, in his own 

 person, the chemist, the physiologist, and the pathologist. 



Every science is slowly and gradually developed. Physio- 

 logical and pathological chemistry forms no exception to this 

 rule : it is still a mere infant science, that has scarcely attained 

 a self-dependent existence. The reader must therefore not 



