128 THE PROTEIN ELEMENT IN NUTRITION 



10-24 grammes in the faeces ; with an intake of 66 grammes, he 

 loses 7 grammes in the faeces ; and with an intake of 43 grammes 

 of nitrogen, he loses 9-38 grammes in the faeces. Kesults such as 

 these defy explanation, except on the assumption that they are 

 not the records of a normally working organism, or that, owing to 

 the difficulty in obtaining accurate collection of the faeces, except 

 when the subjects are under constant supervision, the faecal 

 nitrogen figures do not represent the total loss of nitrogen in some, 

 at least, of the recorded observations. 



Taking into consideration the amount of vegetable material 

 in the composition of the dietaries during the three periods, it 

 would appear very probable that the higher figures given for the 

 loss of nitrogen in the faeces are more likely to be correct than 

 the smaller quantities. It is for this reason that it appears to us 

 probable that the total quantity of faeces passed during the periods 

 by some of the subjects was not collected in full amount. It 

 may be, on the other hand, as Benedict indicates, that the 

 higher figures given for the faecal nitrogen are abnormal, owing to 

 diarrhoea, or a low degree of protein absorption set up by some 

 disturbance in the digestive powers of the alimentary tract, and 

 which is the result of existence on a low level of protein meta- 

 bolism. Whatever the true interpretation of Chittenden's 

 figures may be, the fact remains that they are most irregular, and 

 in the present state of our knowledge cannot be accepted as 

 evidence of the merits of a low protein form of dietary. The 

 fact that only a very small proportion of the men showed a posi- 

 tive nitrogen balance during the first and third periods would 

 make it evident that the metabolism of 50 grammes of protein 

 per day was not sufficient for the needs of the body, even with 

 an average fuel value of 2,830 calories. 



An examination of the results of the nitrogen eliminated in the 

 urine gives equally discordant results. The figures are given 

 in the table on p. 129. 



Here, again, wide variations are recorded in the urinary 

 nitrogen of the different individuals on the same diet : in the 

 first period the limits are 40-12 grammes and 58-07 grammes ; in 

 the second period they are 42-37 and 56-60 grammes ; whilst in 

 the third period quantities of 28-89 grammes and 38-32 grammes 

 are found. On the whole, however, the figures are more uniform 

 than those given for the faeces, and it would therefore appear 

 probable that the subject of the experiment took more care in 



