46 PHYSIOLOGY AT THE FARM. 



of the blood for example, the red particles exist in their pro- 

 per fluid. In the blood the proportion of this fluid medium 

 namely, water with a slight saline impregnation is larger ; in 

 the animal solids the proportion is somewhat smaller ; never- 

 theless it is universally diffused, and must surround the several 

 orders of organic atoms, and, perhaps, even enter between their 

 ultimate constituents. The water of the blood constitutes a 

 kind of liquid atmosphere to the vital solid atoms of that fluid, 

 in which they can perform the special acts for which they are 

 fitted in the freest possible manner. So the water spread 

 throughout the interstices of the living particles of the solids 

 constitutes a like fluid atmosphere, in which these living par- 

 ticles act and react on each other with all possible facility. If 

 the supply of water be withheld throughout the animal economy, 

 all the movements of living action are suspended or extin- 

 guished. It is, in short, the peculiarity of living molecular 

 action that it takes place between solid organic atoms in a 

 fluid medium or circumambient fluid atmosphere. The fluid is 

 doubtless derived from the blood, but in quantity it far exceeds 

 the amount of the blood. Like the serum, or rather the ser- 

 osity of the blood, it contains a small impregnation of soluble 

 saline matter. When organic atoms are spoken of, it is to be 

 understood that these are not chemical atoms, but the smallest 

 living molecules that is, particles endowed with living pro- 

 perties which cannot be divided without the loss of their 

 living character. Of late such bodies have been regarded in 

 physiology as living cells. 



If a horse weigh 1 500 lb., the quantity of his blood will 

 probably be about 300 lb. ; but the amount of water besides 

 diffused through his frame will not fall short of 900 lb. 



If the proportion of water in the blood fall below the just 

 standard, thirst arises, and if drink be supplied the due balance 

 is quickly restored ; if more water be afforded to the blood 



