1 68 MILK [xi 



ounces of fat, and 2 ounces of carbohydrates, the 

 nutritive ratio of such a food would be 



2 : 2 X 2J + 2 = 7, or 1 to 3 J. 

 Digestibility of Food Nutrients. But the value 

 of a food as a source of nourishment does not solely 

 depend on its composition, viz. the percentage of 

 albuminoids and other nutrients it contains, but also 

 on the extent to which these nutrients are capable 

 of being digested. And here we are met with a 

 difficulty, since the digestibility of a food nutrient 

 cannot be absolutely stated, as much depends on the 

 digestion of the individual partaking of the food. 

 Indeed, no better example of this fact could be cited 

 than the case of milk, which is generally found to be 

 one of the most digestible of foods, yet which some 

 people find to be very indigestible. What the cause 

 of such an anomaly is, it is difficult as yet to say. It 

 may be, as has been suggested by recent researches 

 on this subject, that ferments in the digestive canal 

 of some people may cause particular compounds to 

 be changed into injurious, and even poisonous forms, 

 so that it sometimes may be literally true that " one 

 man's meat is another man's poison." But digestion 

 proper is a chemical process, and is capable of being 

 determined with fair accuracy by careful experiment, 

 and our knowledge on this subject has received many 

 valuable additions in the last few years. These have 

 shown that the digestibility of the different nutrients 



