TO 



THE BRITISH ASSOCIATION 



FOR THE 



ADVANCEMENT OF SCIENCE. 



AT the meeting of the British Association in 

 Glasgow, in 1840, I had the honor to present 

 the first part of a report on the then present 

 state of Organic Chemistry, in which I en- 

 deavored to develope the doctrines of this 

 science in their bearing on Agriculture and 

 Physiology. 



It affords me now much gratification to be 

 able to communicate to the meeting of the As- 

 sociation for the present year, the second part 

 of my labors ; in which 1 have attempted to 

 trace the application of Organic Chemistry to 

 Animal Physiology and Pathology. 



In the present work, an extensive series of 

 phenomena have been treated in their chemical 

 relations ; and, although it would be presump- 

 tuous to consider the questions here raised as 

 being definitely resolved, yet those who are 



