FOODS — HUMAN NUTRITION. 765 



and in the final period increased still further, ai)pronching the values observed 

 In the preliminary period. The chlorid excretion diminished during the fasting 

 period and the low-proteid period, returning in the high-proteid period prac- 

 tically to the values observed in the preliminary period. These and other fac- 

 tors are discussed. 



Fasting- studies.— XIII, The output of fecal bacteria as influenced by 

 fasting and by low and high protein intake, N. R. Blatiierwick and P. B. 

 Hawk (Jour. Amer. Chcin. aS'oc, .^6' (lOUf), No. 1, pp. JJf7-irj2). — In connection 

 with the experiment previously noted, the influence of the dietary conditions 

 on fecal bacteria was studied. 



According to the author's conclusions, a 7-day fast lowered the daily excre- 

 tion of fecal bacterial nitrogen by a subject weighing 76 kg. from 1,571 gm. to 

 0.301 gm. " The percentage of the fecal nitrogen which was present as bacterial 

 nitrogen was decreased from 55.82 per cent to 32.29 per cent as a result of th« 

 fast. The percentage of dry bacteria in dry feces was slightly increased. 



" The output of bacterial nitrogen and the output of bacterial substance were 

 approximately the same on a low-protein diet as during fasting.. With the in- 

 gestion of a high-protein diet these values underwent an immediate and pro- 

 nounced increase. 



"The percentage of the fecal nitrogen which was composed of bacterial nitro- 

 gen was about the same in the periods of low and high-protein ingestion. 



" There was no definite relationship between the excretion of fecal bacteria 

 and that of urinary indican. 



" The ingestion of 5.2S gm. of nitrogen after the fast was followed by an 

 excretion of fecal bacteria which was only one-fourteenth as great as when 4 

 times that amount of nitrogen was ingested before the fast." 



The actual weight of the excreted bacterial substance was reduced from 

 14.33G gm. to 0.920 gm. 



Studies on water drinking. — XV, The output of fecal bacteria as influenced 

 "by the drinking of distilled water at meal time, N. R. Blatherwick and 

 P. B. Hawk (Biochem. Bid, 3 {1913), No. 9, pp. 28-40).— This contribution to a 

 long series of studies on the physiological effects of water drinking (E. S. R., 

 29, p. 267) is summarized by the authors as follows: 



" When 500 cc. of distilled water was added to the usual water ingestion at 

 each meal (100 cc), a decrease was noted in the amount of bacterial nitrogen 

 excreted daily in the feces. This held true for two subjects. One subject 

 responded more freely to the influence of the water than did the other. When 

 the water ingestion (100 cc.) was increased by 850 cc. per meal, a more pro 

 nounced decrease in the daily excretion of bacterial nitrogen was observed. 

 This was more emphasized in the one case than in the other, but was very 

 obvious in both. 



" Since the amount of bacterial nitrogen occurring in the feces may, in a way, 

 be considered an index of the utilization of the protein in the food, we are led 

 to conclude that there was a more efficient utilization of the proteins and hence 

 better digestion and absorption when water was taken with meals. In both 

 cases the beneficial results were not confined to the periods of increased water 

 intake, but continued into the periods following. 



" Two subjects fed upon a uniform diet for a period of slightly more than I 

 month were found to have an average content of 57.54 per cent of bacterial 

 nitrogen in the fecal nitrogen. The average amount of dry bacteria excreted 

 per day was 6.1S9 gm. The proportion of dry bacteria in dry feces was found 

 to be 29.94 per cent. 



"A decreased output of urinary indican was observed to accompany the 

 copious water ingestion. There was, however, no definite relationship between 



