Dr. Thomson's Analysis of the Blood of Cholera Patients. 34Y 



drical tin-plate vessels, one highly polished, and the other 

 coated with lamp-black. These were placed in a frame near 

 a britrht steady fire, and protected by a reflector behmd them 

 from*currents of cold air, an equal quantity of water having 

 been poured into each vessel, and a few drops of oil, which 

 formed a film on its surface, and effectually prevented the 

 evaporation of the water till it reached nearly the boihng 



point. • 1 1 1 1 



Thus circumstanced, I found that the water m the black 

 vessel heated, and afterwards boiled off, six and a half times 

 faster than it did in the other ; but when the polished vessel 

 was put into a case, blackened externally, and with a space ot 

 :^th of an inch between them, the water was heated nearly 

 twice as rapidly as it was without the case. 



It may be best for me to abstain, for the present at least, 

 from entering on any theoretical views on the subject of heat, 

 further than just to remark, that I do not see how the facts 

 I have mentioned are to be accounted for on the hypothesis 

 of exchanges of temperature between bodies, not in contact, 

 taking place on the principle of radiation merely, and not of 

 attraction between matter and heat. R.vV. Fox. 



XLIX. Chemical Analysis of the Blood of Cholera Patients. 

 By Thomas Thomson, M.B. F.R.S. Regius Professor of 

 Chemistry in the University of Glasgow*. 



I AVAILED myself of the opportunity presented by the 

 existence of cholera, during the months of February and 

 March 1832, in Glasgow and the neighbourhood, to examine 

 the composition of blood drawn from the patients in well- 

 marked cases of the disease. Abundance of opportunities for 

 this kind of investigation were afforded ; because bleeding 

 had been recommended by the almost united testimony of the 

 Indian practitioners as the most powerful means of checking 

 this formidable disease. It was employed, of course, when 

 cholera first broke out in Glasgow, by aUnost all the medical 

 practitioners. At first bleeding was considered as beneficial. 

 It was said that the patients more frequently recovered after it, 

 and that even when death followed (as was the case with more 

 than one half of those who caught the disease), the patients 

 who had been bled continued to live for a much longer time 

 than those who had not been so treated. By degrees, how- 

 ever, confidence in the efficacy of this remedy began to be 



♦ Communicated by the Authot 



2 Y 2 shaken. 



