An Account of some Experivients on Animal Heat. 453 



Venous blood 121. Water G2-5. Mixture 89; after three 

 »Timutes SS'O ; after seven 87. 



Arterial blood 121. Water 63-5. Mixture 89- 5 ; after three 

 minutes SS'^, and after seven 87. 



Now, allowing- about one degree of the cooling effect to have 

 I'-een prorluced bv the receiver indicated by the admixture of the 

 hot and cold water, calculating the quantity of blood u«cd from 

 the knowledge of its volume and specific gravity, employing the 

 formula given by Professor Robison, which consists in multiply- 

 ing respectively the weight of the water and the blood by the 

 change of temperature, and dividing the first product by the se- 

 cond, the quotient or specific caloric for venous blood ajipears to 

 be as -812, and for arterial as -814; results very similar to those 

 I have obtained with the blood of the sheep. 



In the remaining experiments, blood with the fibrin present 

 was employed, and with this exception they were perfectly simi- 

 lar to those already described. 



The blood used to ascertain its time of cooling was obtained 

 from a sheep ; and one day the vein was opened, and on the 

 next the artery. The capacity of the bottle employed exceeded 

 that of the first by one ounce measure of water ; but it was equally 

 thin. The air of the room was of temperature 69. 



Water cooled from 120 to 80 in 118 minutes 

 Venous blood in .. .. .. 112 



Arterial blood in 113 



And hence, as the latter was of specific gravity 1049, its capa- 

 city for heat seems to be as -913 ; and as the former v/as of spe- 

 cific gravity 1051, its capacity appears to be -903. 



Inthe following experiment, equal volumes of fluid blood and 

 of water were used ; which was easily accomplished by means 

 of a thin bottle with a large mouth, to which a cork was adapted, 

 with a perforation more than sufficiently large to admit the bulb 

 of a very delicate tlierniometer, and of course to allow, v.hen the 

 bottle was filled to tlic brim, the excess to flow out on the in- 

 troduction of the cork, which was always similarly placed. To 

 retard the process of cooling, the bottle v/as closely surrounded 

 by a thick layer of what is commonly called cotton-wool.^ Its 

 capacity vc as equal to five ounce measures of water, or 2400 

 grains. ' It was first filled with cold water, which, when its tem- 

 perature had been ascertained, was thrown into the receiver 

 before used ; it was next filled with hot water of temperature 

 about 110, so that the heat of the glass might be nearly the 

 same as that of the l)lood : and lastly, when the vein or artery 

 had been opened, the bottle was immediately emptied and filled 

 with blood, the temperature of which was ascertained by the 

 y {'■i thcrnio- 



