650 THEORY OF COAGULATION. 



and venous blood of ducks and fowls began to 

 solidify almost immediately, I performed the fol- 

 lowing experiment, with a view of discovering 

 how far the process might be modified by re- 

 ducing the temperature of animals. For this 

 purpose, a healthy pigeon was immersed in water 

 at 47, with the exception of its head, when a 

 thermometer in recto, fell from 108 to 74 in 

 twelve minutes, and the poor bird presented all 

 the symptoms of approaching convulsions, coma, 

 and death. In this state it was decapitated, and 

 its blood made to flow into three saucers, one of 

 which was placed in water at 130, another in 

 water at 110, while the third was exposed to 

 the temperature of the room at about 60, when 

 the blood in the first saucer began to solidify in 

 three minutes, that in the second in four minutes, 

 and that in the vessel at 60, but slightly in seven 

 minutes. Nor is it less worthy of notice, that 

 when the blood of another pigeon was treated in 

 the same manner, but without previously re- 

 ducing its temperature, it coagulated sooner at 

 110 than at 60, sooner at 130 than at either; 

 and more firmly in five minutes, than the blood 

 of the other pigeon at the expiration of thirty mi- 

 nutes. Nor is it more strange that caloric should 

 determine both the fluidity and coagulation of 

 blood, than that attraction and repulsion, con- 

 traction and expansion, should be modified ef- 

 fects of one and the same physical cause. 



