ON PUEE WATER. 
555 
into one pail^ whilst the other four would contain the water. 
In more accurate figures^ the solid constituents of a man^s body, 
weighing 154 pounds, would be 43 pounds of solid and gaseous 
matter, and 111 pounds of water. 
Neither the water nor the other constituents of a man^s 
body are permanently retained. Life does not so much 
consist in the chemical changes which our daily food is 
undergoing as in the destruction of the tissues which are 
formed out of the food. Blood, muscle, and nerve formed 
from the food of yesterday become the source of active life 
to-morrow. That which to-day is available flesh is to-morrow 
rejected from the system. The water of the tissues is removed 
at the rate of from 80 to 100 ounces a day. Of this 50 ounces 
pass off by the kidneys, 30 by the lungs, and 14 by the skin. 
Of course season affects these quantities, and the larger 
the person and the greater the drinker, the more water is got 
rid of. 
Not only is water necessary to the sustaining of the human 
body, but all other constituents are taken into the body 
by its agency. All our food naturally contains water. 
Here is the result of analyses of various articles of food. 
One hundred pounds contain the following quantities of 
water : — 
Potatoes 
75 lbs. 
Cabbage 
92 „ 
Flour 
14 „ 
Eice 
13 „ 
Bread 
44 „ 
Milk 
86 „ 
Beef 
50 „ 
Mutton 
44 „ 
Fish 
78 „ 
Eggs 
... ' 80 „ 
Cheese 
40 „ 
From this list it will be seen that all our ordinary food 
contains water. But this is not enough to carry the various 
substances we use as food into the system. The sugar, the 
starch, the oil, the fibrin, and albumen must all be dissolved 
and carried into the system by the aid of water. Hence we 
partake of beverages. We drink tea, coffee, chocolate, beer, 
soup, and other fluid foods. In all these cases we are merely 
flavouring the water which it is necessary for us to take in 
order to enable the stomach to dissolve and take up the more 
solid forms of our food. 
The quantity of water contained in the meat, bread, and 
vegetables of which man indirectly partakes in his food is 
about one-fourth of the quantity of water he requires for daily 
