A HISTORY OF METABOLISM 39 



It is evident that 1061 gm. of oxygen would have been inspired and 

 1231 gm. of carbonic acid expired, according to this calculation. He 

 finds that his figures for carbonic acid elimination accord with those of 

 Andral and Gavarret (see below). He calculates the heat production as 

 follows : 



335.7 g. C X 7.200 calories = 2417.040 calories from C 

 20.8 g. H X 34.600 " = 719.680 " " HI 



Total 3136.720 



These calories were calculated for a man from the food partaken 

 during the winter months. 



Barral makes the further analysis of the heat produced by various 

 individuals in 24 hours: 



Total Calories 



Subject. calories perkgm. 



Barral, in winter (age 29 yrs. ; wgt. 47.5 kgm.) . . . 3,136.720 66.036 



Barral, in summer 2,312.000 48.673 



BarraFs son (age 6 yrs. ; wgt. 15 kgm.) 1,223.960 81.597 



Laboratory servant (age 59 yrs.; wgt. 58.7 kgm.). 2,559.080 43.595^^ 



Woman (age 32 ; wgt. 61.2 kgm.) : 2,541.100 41.521 -* 



The quantity of nitrogen in the food was always greater than that 

 found in the evacuation, so much so that a part must have been eliminated 

 in the respiration. This portion was one-third or one-quarter of the 

 nitrogen taken in the food but was not more than the hundredth part of 

 the volume of carbonic acid eliminated. The loss of food nitrogen was 

 estimated as not more than six ten-thousandths of the total volume of air 

 expired. 



Barral did not know that his urinary nitrogen analyses were faulty. 



Barral criticizes the contemporary work of Liebig as follows: "Liebig 

 has attempted the solution of the question which occupies us by the same 

 method and as concerns man. This skilful chemist was content to measure 

 the principal foods of a company of the grand ducal guard of Hesse- 

 Darmstadt and to regard the minor food-stuffs as the approximate equiva- 

 lent of the material found in the feces and urine so far as carbon content 

 was concerned. Be also made similar valuations of the food-stuffs of 

 prisoners at Giessen and at Marienbad and of a family composed of five 



