INCOME AND EXPENDITURE OF BODY. 433 



Solid and gaseous matter, . .^ . 17,150 grains (1,113 grms.) 

 Water (either fluid or combined with the 

 solids and gaseous matter), . . 49,500 " (2,695 " ) 



The matter thus lost by the body is matter the chemical attractions 

 of which have been in great part satisfied; and which remains quite use- 

 less as food, until its elements have been again separated and re-arranged 

 by members of the vegetable world. It is especially instructive to com- 

 pare the chemical constitution of the products of expenditure, thus 

 separated by the various excretory organs, with that of the sources of 

 income to be immediately considered. It is evident from these facts 

 that if the human body is to maintain its size and composition, there 

 must be added to it matter corresponding in amount with that which is 

 lost. The income must equal the expenditure. 



2. Sources and Amount of Income. The Income of the body 

 consists partly of Food arid Drink, and partly of Oxygen. 



Into the stomach there is received daily: 



Solid (chemically dry) food, . . . 8,000 grains (520 grms.) 

 Water (as water, or variously combined 



with solid food), .... 35,000-40,000 " (2,444 " ) 



By the Lungs there is absorbed daily: 

 Oxygen, . 13,000 " (844 " ) 



The average total daily receipts, in the shape of food, drink and oxy- 

 gen, correspond, therefore, with the average total daily expenditure, as 

 shown by the following table. 



Income. 



Solid food, . . 8,000 grains. 

 Water, . . 37,650 " 

 Oxygen, . . 13,000 " 



58,650 grains. 

 (3,808 grms., or about 8J- Ib.) 



Expenditure. 



Lungs, . . 20,000 grains. 

 Skin, . . . 11,750 " 

 Kidneys, , . 24,100 " 

 Intestines, . . 2,800 " . 

 (Generative and mam- 

 mary-gland products 

 are supposed to be 

 included) 



58,650 grains, 

 (about 3, 808 grms.) 



These quantities are approximate only. But they may be taken as 

 fair averages for a healthy adult. The absolute identity of the two num- 

 bers (in grains) in the two tables is of course diagrammatic. No such 

 exactitude in the account occurs in any living body, in the course of any 

 given twenty-four hours. But any difference which exists between the 

 two amounts of income and expenditure at any given period, corresponds 

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