220 COIvrPENDlUM OF. THE VETERINARY ART. 



or coagiiluble Ij^mpJi. The proportion, which 

 these component parts of the blood bear to 

 each other, seems to depend upon ihe state of 

 the system at the time it is drawn. V\^heii 

 the body is ileal thy and vigorous, we fmd but 

 little serum ; wheii it is preternatiiraiiy exciied, 

 or in a state of inflammation, there is still less; 

 and when the animal is weak and debilitated, 

 tliere is generally an abundance of serum. 

 Another circumstance to be attended to in 

 examining blood is the firmness or tenacity of 

 the coagulum. In health, the blood, when 

 dravvn^'and sulYered to coagulate, is of a mode- 

 rately firm consistence, and easily broken ; but 

 when the system is iiighly excited, as in general 

 inflammation, so great is the tenacity of the 

 mass, that the finger can scarcely penetrate 

 It . On the other hand, when the powers of life 

 are weak, as in the latter stage of symptom- 

 atic fever, the blood almost loses its power 

 of coaoulatin*]:. I recollect a piandered horse 

 that was made the subjectof experiments, and 

 that died in consequence of large and repeat- 

 ed doses of mercury ; the debility this pro- 

 duced was excessive; and the blood appeared 

 as tiiin, and nearly of the same colour, as claret. 



