AND PROPERTIES OF THE BLOOD. 223 



heavier than arterial, as 1052 is to 1049 ; but, as before 

 observed, these data vary. — The temperature of the blood in 

 the horse is about 100; and in the ox, 102; but various 

 circumstances tend to increase or decrease it. Arterial 

 blood is usually one or two degrees warmer than venous. 

 Some diseases reduce the heat of the blood, and inflam- 

 mations are also supposed capable of augmenting it. The 

 quantity an animal contains, in proportion to his bulk, has 

 been endeavoured to be ascertained : but the results have 

 been various. Very fat animals are found usually to have 

 proportionably less than lean ones ; and in those in a state 

 of close confinement, the quantity is found to be smaller 

 than in the wild. A medium sized horse has lost forty-four 

 pounds. — The chemical property of the blood is an im- 

 portant subject to the medical student. It appears to be 

 variously compounded, but is most distinctly separable into 

 two parts ; the one solid and red, called the clot ; the other 

 fluid and slightly tinged with yellow, termed the serum ; or, 

 it is divisible into serum and crassamentum. The process 

 which separates them is termed coagulation. The coagulum, 

 or crassamentum, is found to be composed of two parts : 

 that to which it owes its colour is called its red globules ; 

 the other component, or that which gives consistence and 

 adherence to the red particles, is known by the names of 

 coagulable lymph, or fibrin. The red particles are con- 

 nected with the strength of organs ; and parts subjected to 

 the greatest exertions, as muscles, are fullest of them ; for 

 as muscles are more or less highly coloured, so have they 

 proved stronger or weaker. From known facts, one would 

 infer that the red globules are longer in forming than the 

 other parts. The ^'&rm forms the other portion of the clot, 

 and appears to be the most important part of the vital fluid. 

 After the perfect abstraction of the serum and red particles by 

 maceration, the fibrin will be left white, tough, and fibrous ; 

 bearing in general aspect, as w^ell as chemical characters, 

 a close resemblance to muscular fibre when deprived of its 

 connecting membranes and colouring matter. It appears to 

 be that part of which all the solids of the body are imme- 

 diately framed : it forms the callus of bones, and can become 

 organized whenever extravasated. It spontaneously coagu- 

 lates, is soluble in alkalies, but insoluble in water, oils, or 



