14 WONDERS OF ORGANIC LIFE. 



a dark modena-red, the latter of a bright scarlet. 

 The specific gravity of venous blood is greater 

 than that of arterial, and this appears to be 

 owing to the carbon contained in the latter. 

 The specific gravity of the blood, averaging 

 1050, (water being 1000,) is capable of in- 

 crease or decrease, according to health and diet; 

 and in the higher animals it always exceeds 

 that of the lower. Its temperature is greater 

 in birds than in any other warm-blooded 

 animals. 



The separation of blood into serum and 

 crassamentum is the result of its death, or 

 perhaps the mode of its dying. During this 

 process a peculiar odour is exhaled, in the 

 form of a vapour, from which we turn away 

 with aversion, and from which the ox instinc- 

 tively recoils when forced into the slaughter- 

 house. The quantum amount of serum in 

 proportion to the crassamentum varies in dif- 

 ferent animals, and in the same animal, according 

 to its condition and state of health. The serum 

 is most abundant in small feeble animals, desti- 

 tute of energy ; small in quantity in animals of 

 muscular vigour and ferocious habits. Its 

 general colour is yellowish, often with a tinge 

 of pale green ; it is adhesive, and has a saline 

 flavour. In its chemical composition it is es- 

 sentially albumen, and coagulates by heat. At 

 the temperature of 160° it is converted into a 

 substance similar in appearance and character 

 to the luhite of a hard-boiled egg. This fluid 

 albumen contains several earthy and neutral 



