AUTHOR'S PREFACE. xi 



as calculi, tubercular and carcinomatous matter, dropsical 

 effusions, &c. 



I have made myself practically conversant with the most 

 approved methods of analysing the different fluids and solids 

 described in this work ; and, as far as my resources permitted, 

 I have endeavoured to determine the various physical and che- 

 mical modifications they undergo in the course of different dis- 

 eases. My attention has been especially directed to the study 

 of those fluids that are of the greatest importance to the 

 practical physician. Within the space of a few years I have 

 made about 170 quantitative analyses of various animal matters, 

 of which the very large majority refer to human blood, milk, 

 and urine, and on which I lay the foundation for the patholo- 

 gical chemistry of those fluids. In fact, without these analyses 

 it would have been impossible to publish a work worthy of the 

 name of ' The Chemistry of Man ;' for the essays of Andral 

 and Gavarret on the Blood, and of Becquerel on the Urine, did 

 not appear until I had made considerable progress in my work. 

 I have deemed it, in every case, my duty to incorporate the 

 results of other chemists with my own, and if, in any instance, 

 I have failed in acknowledging the sources from which my 

 statements have been drawn, the fault is one of inadvertence, 

 not of design. All purely phj^siological matter, not bearing 

 directly on chemistry, has been omitted ; but microscopic in- 

 vestigation, especially in those instances in which it strengthens 

 the evidence of experimental chemistry, has been deemed legi- 

 timately deserving of a place in this treatise. 



My views regarding the metamorphosis of the blood, and its 

 relation to nutrition and animal heat, were first communicated, 

 at Erlangen in the autumn of 1840, to the medical and chemi- 

 cal section of Associated Naturalists ; and my subsequent re- 

 searches into the chemical constitution of the blood and urine 

 confirm my belief in their general accuracy. These views may 

 be summed up in the following terms : The blood is subjected 



