Dr. Davy's Account , &c. 
591 
The experiments that I have made, will be described in the 
two following sections, and in the last will be offered the few 
remarks and conclusions which naturally arise, and are fairly 
deducible from the results. 
1. On the capacities of venous and arterial Blood for Heat, 
I must premise, that my object has been to endeavour to 
ascertain the relative capacities of venous and arterial blood 
for heat, rather than their exact specific caloric. ‘ The latter, 
from many circumstances, is difficult to be accomplished ; 
whilst the former is comparatively easy, and in a theoretical 
point of view is probably equally useful. 
I have employed both the methods commonly used. I shall 
mention most of the experiments that I have made, without 
noticing the repetitions of them, and shall begin with those on 
the times of cooling of equal volumes of venous and arterial 
blood. 
The blood used was from the jugular vein and the carotid 
artery of a lamb, about four months old. It was received in 
bottles, and to remove the fibrin, which is a great impediment 
in experiments of this kind, it was immediately stirred with a 
wooden rod. In respect to colour, the difference between the 
venous and arterial blood was not so great as in the sheep's, 
and this in a great variety of instances I have always observed, 
the venous being of a less dark hue. The specific gravity of 
the venous blood, without the fibrin, was found to be 1050, 
and that of the arterial 1047. 
A glass bottle equal in capacity to 2518 grains of water, 
and weighing 1332 grains, was filled respectively with water 
and venous and arterial blood of the temperature of the room 
4 G 2 
