THE BLOOD. 27 



blood was found to be fluid, and in a few minutes after, being 

 laid open to the air, it coagulated as usual. Now, as the blood 

 in the last experiment was coagulated, when the heat had 

 never risen above 1201; and in this experiment was fluid, though 

 it had been exposed to a heat of 114; we may therefore con- 

 clude that the coagulable lymph in the blood of a dog in health 

 is fixed in a degree of heat between 114 and 120 of Fahren- 

 heit's thermometer. 



As to the degree of heat at which the lymph in human blood 

 coagulates, I have not yet had an opportunity of trying it in a 

 more satisfactory way, than with the mixture with Glauber's 

 salt, in which state it coagulates at 125. But, as we find 

 that the human blood and that of a dog jelly nearly in the 

 same time, when exposed to the air, I think it probable that 

 the precise degree of heat at which the lymph of the human 

 blood coagulates, is between 114 and 120^ (xvi). I have 

 thought of making the experiment on the umbilical cord of a 

 recent placenta, which perhaps is the most likely way of coming 

 at the truth. 



The degree of heat, at which the serum of the blood (which 

 should not be confounded with the lymph) coagulates, is ge- 

 nerally said to be 150 ; but from my experiments I am inclined 

 to believe it requires a greater heat to fix it. They were made 

 in the following manner : 



(xvi.) In my experiments, mentioned in Note in, a mixture of 

 liquor sanguinis and a neutral salt appeared to be affected by heat only 

 like a very concentrated solution of albumen. When diluted with water, 

 and kept at a heat of 125 or 126, there was no precipitation of al- 

 bumen ; but the self-coagulating power of the mixture was com- 

 pletely destroyed. These results agree essentially with those of 

 Mr. Prater. a The heat of some animals approaches 1 14. In some 

 healthy birds at Ceylon, Dr. Davy b found it 111; and 113 under the 

 left ventricle of the heart in a soldier at Malta, three hours and a 

 half after death, in which case the blood was liquid, and yet coagulated, 

 as Dr. Davy informs me, on exposure to the air. 



We want some exact observations on the temperature of fishes in hot 

 springs. Sonneret is reported to have seen fishes, apparently not in- 

 commoded, in a spring as hot as 187 Fahrn., in the island of Lugon, 

 one of the MantiUes ; and Cuvier received some fishes from the waters 

 of Cassa and Tozer, which are said to be as high as 170 Fahrn. c 



a Exp. Inq. in Chem. Physiol. part i, c See Dr. Hodgkins's tr. of Edwards on 



p. 114. Physical Agents, 8vo, Lond. 1832. 



b Researches, i, 186-7, 230. 



