98 Veterinary Elements. 



This red coloring matter combines very readily with the 

 oxygen of the air. The paleness often noticed in weak 

 animals, whether weak from lack of good food, pure air, 

 or as a result of loss of blood, is due to a deficiency in 

 number of the red cells, and therefore of the red color- 

 ing matter, the coloring matter may be dissolved out, 

 thus accounting for the peculiar coloration of meat that 

 has been frozen and then thawed. The difference in the 

 contents of the red blood cells before and after birth are 

 made use of in the human race for the detection of crime. 

 These cells contain a nucleus before birth, after they do 

 not, so that in case of the finding of a dead child, if no 

 nuclei are found in its red blood cells it is assumed that 

 it has lived a day or two, if nuclei are found the child 

 was still born. 



White blood cells have an average diameter of -^-gVo of 

 an inch. 



The amount of blood in the body varies with the ani- 

 mal, it has been estimated in the horse to be about equal 

 to ^g of the body weight, in man about -^. 



The blood pump (heart) is a hollow muscle, cone 

 shaped, and in the horse about 5J Ibs. in weight. It is 

 situated in the chest cavity between the right and left 

 lungs, its apex being downwards. It is divided into two 

 well marked halves, each of which is again divided into 

 an -upper chamber or auricle and a lower chamber or 

 ventricle, consequently we speak of the right side of the 

 heart and the right auricle, or ventricle, as the case may 

 be. The division between the auricles and ventricles is 

 not as perfect, being only by valves, as is the division 

 between the right and left heart. These valves serve 



