56 AS TRUE AS POETIC, 



animals liable to be called ou for the most rapid circulation or 

 most remarkable for speed and endurance. 



1 1 0. — We have spoken of these blood corpuscles as composing 

 thirteen per cent, of the blood, but that is only a rough average 

 estimate. They vary from something like five to twenty per 

 cent., and the cause of their variation is a most important 

 consideration in connection with the subject of this chapter. 

 The smallest per centage is found in the blood of poor needle 

 Avomen, or of any females poorly fed, getting little active exercise, 

 and abo\'e all shut up in close rooms. The largest per centage 

 is found in the blood of man, or any other animal, constantly 

 at Avork in the cold open air with enough good nutritious food. 

 With women shut up from the open air, the blood cells are 

 usually so few that their feet are kept warm with difficulty, if at 

 all. With too much hard work in the cold open air, the blood 

 cells may get so large a per centage of the blood as to give a 

 tendency to inflammation, when food or drink of an inflammatory 

 character is indulged in. Poor Ijlood can only be made good 

 blood by good food and plenty of exercise in the open air ; high 

 feeding without the exercise in the open air will only do mischief, 

 and especially endanger the lungs. The blood cells can be slowly 

 increased by the open air exercise, they can be rapidly decreased 

 by shutting up in bad air, they can be instantly lessened by 

 bleeding, and the corpuscles so lost cannot be restored for some 

 weeks or months, under the very best treatment. 



Thus Mrs. Heman's allusion to the "rich blood" of the 

 Arab, is as physiologically correct, as it is poetically beautiful, 

 and such rich blood must be cultivated in any animal that is to 

 be capable of any extraordinary exertion. In other words, if the 

 horse is to lie fit for much, he must both be taken into the open 

 air, and the pure air must be taken into him, if he is shut up at 

 all. TTc must not breathe air that has already parted with its 

 free oxygen, and become loaded with carbonic acid gas, or with 

 the ammonia arising from stones reeking with the excretions of 

 his own body. 



1]]. — Now we come at last to the air itself. Roughly 

 speaking the atmospheric air consists of 70 parts nitrogen or 



