104 THE CHEMICAL COMPOSITION OF THE BODY 



Quantity of Water in Per Cent. 



Teeth 10.0 Bile 88.0 



Bones 13.0 Milk 88.7 



Cartilage 55 -o Pancreatic juice. ... 90.0 



Muscles 75- Urine 93-6 



Ligament 76.8 Lymph 96.0 



Brain 78.9 Gastric juice 97-5 



Blood 79 . 5 Perspiration 98.6 



Synovia 80 . 5 Saliva 99-5 



In all the fluids and tissues of the body blood, lymph, muscle, gland, 

 etc. water acts the part of a general solvent, and by its means alone circula- 

 tion of nutrient matter is possible. It is the medium also in which all fluid 

 and solid aliments are dissolved before absorption, as well as the means by 

 which all, except gaseous, excretory products are removed. All the various 

 processes of secretion, transudation, and nutrition depend of necessity on 

 its presence for their performance. 



The greater part, by far, of the water present in the body is taken into 

 it as such from without, in the food and drink. A small amount, however, 

 is the result of the chemical union of hydrogen with oxygen in the oxidations 

 of the body. 



The loss of water from the body is intimately connected with excretion 

 from the lungs, skin, and kidneys, and, to a less extent, from the alimentary 

 canal. The loss from these various organs may be thus apportioned (quoted 

 by Dalton from various observers): 



From the alimentary canal (feces) 4 per cent. 



From the lungs 20 per cent. 



From the skin (perspiration) 30 per cent. 



From the kidneys (urine) 46 per cent. 



100 



Under some conditions the loss of water from the alimentary canal may 

 be enormously increased, as in acute diarrheas. In young children and 

 babies in particular this fact is often not realized and not enough water is 

 given by the mouth to supply the loss. The result is a considerable 

 concentration of the blood and tissues, a relative dessication that may 

 prove very injurious. 



