THE CHEMISTRY OF COOKERY. 501 



search (especially of endowed research), a staff of obedient assistants 

 to do the drudgery. 



The comparison specially demanded is between cheeses made with 

 rennet and those Dutch and factory cheeses the curd of which has been 

 precipitated by hydrochloric acid. Theoretical considerations point to 

 the conclusion that in the latter much or even all of the phosphate of 

 lime may be left in solution in the whey, and thus the food-value of 

 the cheese seriously lowered. We must, however, suspend judgment 

 in the mean time. 



In comparing the nutritive value of cheese with that of flesh, the 

 retention of this phosphate of lime nearly corresponds with the reten- 

 tion of the juices of the meat, among which are the phosphates of the 

 flesh. 



These phosphates of lime are the bone-making material of food, 

 and have something to do in building up the brain and nervous matter, 

 though not to the extent that is supposed by those who imagine that 

 there is a special connection between phosphorus and the brain, or 

 phosphorescence and spirituality. Bone contains about eleven per cent 

 of phosphorus, brain less than one per cent. 



The value of food in reference to its phosphate of lime is not merely 

 a matter of percentage, as this salt may exist in a state of solution, as 

 in milk, or as a solid very difficult of assimilation, as in bones. That 

 retained in cheese is probably in an intermediate condition — not actu- 

 ally in solution, but so finely divided as to be readily dissolved by the 

 acid of the gastric juice. 



I may mention, in reference to this, that, when a child or other 

 young animal takes its natural food in the form of milk, the milk is 

 converted into unpressed cheese, or curd, prior to its digestion. 



Supposing that on an average cheese contains only one half of the 

 six per cent of phosphate of lime found, as above, in the casein, and 

 taking into consideration the water contained in flesh, the bone, etc., 

 we may conclude generally that one pound of average cheese con- 

 tains as much nutriment as three pounds of the average material of 

 the carcass of an ox or sheep as prepared for sale by the butcher ; or, 

 otherwise stated, a cheese of twenty pounds weight contains as much 

 food as a sheep weighing sixty pounds as it hangs in the butcher's 

 shop. 



Now comes the practical question. Can we assimilate or convert 

 into our own substance the cheese-food as easily as we may the flesh- 

 food? 



I reply that we certainly can not if the cheese is eaten raw ; but 

 have no doubt that we may if it be suitably cooked. Hence the para- 

 mount importance of this part of my subject. A Swiss or Scandinavian 

 mountaineer can and does digest and assimilate raw cheese as a staple 

 article of food, and proves its nutritive value by the result ; but feebler 

 bipeds of the plains and towns can not do the like. 



