NUTRITION 



XXVIII 



sheet in a metabolism experiment. 



Vol. 3, part I, p. 497, details of experiment No. 37. 



EXPENDITURE. 



The figures are contained in Tables 1-9 and also Table 19. In 

 presenting this synopsis the water intake shown is the sum of that 

 in the food and drink, and the hydrogen output of urine and faeces is 

 the sum of the hydrogen from water and from organic compounds. 

 The presentation of the energy expenditure has been altered, and the 

 loss by radiation is the heat value obtained from the calorimeter less 

 the heat value of the external work and the heat value of the water 

 which had condensed in the calorimeter as these latter are included 

 in the heat measured by the water stream of the calorimeter. 



For very small animals a Dewar flask can be used as a heat 

 insulator.* 



The heat absorbing apparatus consists of a copper tube 

 with copper discs brazed on to it. Cool water flows through 

 the copper tube and absorbs the heat from the interior of the 

 inner chamber. The temperature of the water entering and 

 leaving the chamber is measured and also the total amount of 

 water passing through. The amount of heat is obtained by 

 multiplying the difference of temperature by the amount of 

 water and by the specific heat of water at the temperature of 

 the experiment. 



The gas analysis is carried out by causing the air to pass 



* A. V. Hill and A. M. Hill, Journ. PhysioL, 1913, vol. 46, p. 81. 

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