CHEMICAL PHYSIOLOGY. 31 



In my research on cholera I have shown that in Biooa change 



/ m^cnolera. 



that disease the serum of the blood, being changed in 

 its constitution in consequence of the alvine flux, refuses 

 to perform the functions which it performed before. It 

 exhausts water and other matters from the blood- 

 corpuscles, and the latter thereupon cease to carry 

 oxygen ; oxydation does not take place any longer, 

 hence the temperature falls, and the algid condition of 

 cholera is produced. In yellow fever, and in a disease 

 which occurs in England, paroxysmal cruenturesis, the 

 hematocrystalline of a portion of the blood-corpuscles 

 leaves them, and in the one disease decomposes and 

 colours the skin yellow, in the other appears in 

 the urine with a red or reddish-brown colour. A 

 similar decomposition takes place in some cases of 

 pygemia, and in poisoning by arseniuretted hydrogen, 

 and by the bite of venomous serpents. Several 

 poisons, such as sulphuretted hydrogen, carbonic 

 oxyde, hydrocyanic or prussic acid, kill or injure 

 by decomposing the hematocrystalline, or com- 

 bining with it, and keeping the oxygen out. Thus 

 the study of many diseases requires an intimate know- 

 ledge of the constitution of the blood-corpuscles. The 

 value of this we have only just begun to appreciate, 

 and the chemical and optical methods of investigation 

 applied with rigorous accuracy will bring us not only 

 the explanation of normal phenomena at present re- 

 maining obscure, but also useful practical information 

 on the nature of diseases, processes of poisoning, and 

 their treatment by prevention or cure. 



One of the most remarkable properties of the blood o 



