70 BIOLOGICAL PROBLEMS 



used for food directly, the other (B) if they are used 

 for brewing. The sugar contains no protein, and is 

 therefore omitted from the table. 



TABLE III 



Protein of the Protein of the Protein of the 



Original Materials. Food for Man. Food for Cattle. 



48,000 tons.-}- 32,000 tons (A). 

 Barley 80,000 tons. ^ ^ ' \ 5.625 

 Grits 5,625 





85.625 



+ 62,000 ,, (B). 



Gain and loss 49,375 +3.o ,, 



Total loss of protein, 19,375 tons = 22 2 P er cen t. 



The barley flour and grits, which might be utilized 

 as human food, contained 53,625 tons of protein; the 

 beer obtained from these had only 4250 tons. 1 Over 

 90 per cent of the protein available for man is thus 

 lost in the process of brewing. The protein fed to 

 animals, on the other hand, is nearly doubled, and 

 this might be regarded as compensating for the loss 

 to man, since it may be recoverable from the animal 

 in the form of milk. As a matter of fact, however, 

 this recovery is very incomplete, and is quite inade- 

 quate to cover the loss; for the estimate is made that 

 for the 62,000 tons of protein given to the cow, only 

 5170 tons are returned in the form of milk, so that, 

 even taking this into account, the loss of protein to 

 man by using food materials for brewing amounts to 

 about 80 per cent. On another calculation, the total 

 protein obtained for man and animals is less by 

 22^ per cent than if the materials had been used 

 directly as food. 



1 The protein of beer is here taken at o.i per cent. Sharpe finds it vary in 

 different beers from 0.038 to 0.185 per cent ; this would give a protein content 

 of the whole of the beer brewed in 1916 of 1600 and 8000 tons respectively. 



