Mr Hermann on Cholera Alorbus. 129 



of the disease, which seems now without doubt to have gained 

 an entrance into England. 



Having been commissioned by the constituted authorities at 

 Moscow to institute chemical investigations into the nature of 

 cholera, Mr Hermann made analyses of the blood, urine, and 

 bile obtained from patients in different stages of the disease, as 

 also of the vomited fluid and of the excrement. 



At the commencement of his analysis of the blood of a cholera 

 patient, he was surprised by finding that the clot contained a 

 Jree acid. This he at first conceived to be a peculiarity in the 

 blood of cholera patients, but he very soon found that his own 

 blood, at a time when he was in perfect health, possessed the 

 same, or rather stronger, acid properties than that of the cholera 

 patient. Aware that chemists in general describe the blood as 

 alcaline, he was induced to make an analysis of healthy blood, 

 with a view of ascertaining the nature and quantity of the free 

 acid which it contains. 



Healthy Blood. — Mr Hermann's own blood, allowed to stand 

 for twenty-four hours, until it separated completely into serum 

 and clot, contained 57 of serum and 43 of moist clot in 100 

 parts. He found that the serum of this blood slightly reddened 

 litmus, but not so powerfully as the clot did ; and this he could 

 not attribute simply to the colouring matter of the clot, as pure 

 water did not receive a colour from it so soon as the blue litmus 

 solution was changed to red. By boiling the serum and clot 

 with carbonate of baryta, in a vessel connected with a mercurial 

 pneumatic apparatus, he found there were disengaged from 100 

 volumes of serum, 18.1 volumes, and from the clot 21.2 volumes 

 of gaseous carbonic acid. 100 parts of the same clot were then 

 boiled without carbonate of baryta, and there were disengaged 

 from them 10.4 volumes of gaseous carbonic acid : 10.4 volumes, 

 therefore, of the free acid in the clot, consisted of carbonic acid ; 

 the other 10.8 volumes he found to be acetic acid. 



The blood of a healthy pregnant woman was analyzed, with 

 very nearly the same results *. 



• It must be obvious that a much more extensive series of experiments 

 than that adduced by Mr Hermann will be necessary to establish the accu- 

 racy of this result, differing so materially from that obtained by most che- 

 mists. 



OCTOBER — DECEMBER 1831. I 



