AS WELL AS FOOD. 13 



ganism, after having entered into combination, within 

 the body, with the oxygen of the atmosphere. 



If we assume, with Lavoisier and Seguin, in order 

 to obtain a foundation for our calculation, that an adult 

 man receives into his system daily 32| oz. (46,037 cu- 

 bic inches = 15,661 grains, French weight) of oxygen, 

 and that the weight of the whole mass of his blood, of 

 which 80 per cent, is water, is 24 Ibs. ; it then appears, 

 from the known composition of the blood, that, in order 

 to convert the whole of its carbon and hydrogen into 

 carbonic acid and water, 64,103 grains of oxygen are 

 required. This quantity will be taken into the system 

 of an adult in four days two hours. (2) 



Whether this oxygen enters into combination with 

 the elements of the blood, or with other parts of the 

 body containing carbon and hydrogen, in either case 

 the conclusion is inevitable, that the body of a man, 

 who daily takes into the system 32| oz. of oxygen, must 

 receive daily in the shape of nourishment, as much car- 

 bon and hydrogen as would suffice to supply 24 Ibs. of 

 blood with these elements ; it being presupposed that 

 the weight of the body remains unchanged, and that it 

 retains its normal condition as to health. 



This supply is furnished in the food. 



From the accurate determination of the quantity of 

 carbon daily taken into the system in the food, as well 

 as of that proportion of it which passes out of the body 

 in the faeces and urine, unburned, that is, in some form 

 in which it is not combined with oxygen, it appears that 

 2 



