ANNUAL RECEIPTS AND WASTE IN MAN. 11 



compensation. But even after a year, if a state of health is maintained, 

 the weight may remain precisely what it was, and this may continue year 

 after year in succession. The consumption of large quantities of solid, 

 liquid, and gaseous matter does not therefore necessarily add to the 

 weight. 



There are two periods of life for which this observation will not hold 

 good. They are infancy and old age. During the former the weight in- 

 creases from day to day, and during the latter it slowly declines. 



If there be thus causes for the increase of weight of the living system, 

 there are also causes for its diminution. Setting aside the minor ones, 

 these may be chiefly enumerated as loss by urine, by faeces, by transpired 

 and expired matters. By transpired matters, are meant such as escape 

 under the form of liquids and gases from the skin, and by expired mat- 

 ters, vapors and gases escaping from the lungs. There is, therefore, a 

 tendency to an increase and a tendency to a diminution of the weight, 

 and, in the condition of equilibrium we are considering, these must bal- 

 ance one another. 



If a man of the standard weight abstains from the taking of water and 

 food, a good balance will prove that in the course of less than an hour he 

 has become lighter. If he still persists, it needs no instrument to detect 

 what is going on ; the eye perceives it, for emaciation ensues. 



How, then, is it possible for a living being to continue at its standard, 

 except the causes of increase are precisely equal in effect to the causes 

 of diminution? Overlooking minor ones, we may therefore assert that 

 the sum total of food, water, and atmospheric air taken in a given period 

 of time is precisely equal to the sum total of all the losses by urine, fae- 

 ces, transpired, and expired matters ; for if the receipts were greater, the 

 weight must increase if the losses were greater, the weight must dimin- 

 ish. Persistency in this respect proves equality, and the case is just as 

 simple as in the common affairs of life ; he who pays less than he receives 

 grows rich ; if his payments are more than his receipts, he becomes poor ; 

 but his condition is unchanged if his payments and receipts are equal. 

 Infancy, old age, and manhood answer to these circumstances respect- 

 ively. 



From the army and navy diet scales of France and England, which of 

 course are based upon the recognized necessities of large Quantity of 

 numbers of men in active life, it is inferred that about 2 J 

 pounds avoirdupois of dry food per day are required for each year, 

 individual ; of this about three quarters are vegetable and the rest animal. 

 At the close of an entire year the amount is upward of 800 pounds. 

 Enumerating under the title of water all the various drinks coffee, tea, 

 alcohol, wine, &c. its estimated quantity is about 1500 pounds per an- 

 num. That for oxygen may be taken at 800 pounds. 



