20 



follows, with all its long train of disagreeable companions. The fact to 

 which attention is now to be drawn reconciles these two apparently contra- 

 dictory statements. In describing meat as rich in protein or bread as a 

 carbohydrate food, it is not meant that these foods contain only protein or only 

 starch. In almost every case these nutrients are combined with a greater or 

 less amount of the other four classes of nutritive substances as well as with 

 cellulose or similar indigestible fibrous matters, from which it is the work of 

 the digestive organs to separate them. The residue remains in the intestine to 

 serve the purpose of " ballast," which, in the course of its expulsion from the 

 intestine, carries with it other undesirable products, which have accumulated 

 in the process of digestion. 



Let us suppose that a man requires 4% oz. of protein to repair the daily 

 wear and tear of his body ; he could find no foodstuff in which this protein 

 occurs in pure uncombined concentrated form. He would have to eat 1^ Ib. 

 of meat, for instance, in order to get his 4% oz. ; or if he preferred eggs and 

 milk, he would have to drink two quarts of milk and eat nine eggs ! Of course, 

 such a diet is mentioned only to illustrate my point, not as an example to be 

 followed. Once more it must be emphasized that 



THE METHODS OF EXPERIENCE 



find full confirmation when subjected to the tests now under consideration in 

 respect of food-values. A healthful diet must be a mixed diet ; then the excess 

 of a particular nutrient in one article, such as protein in meat or fish, is 

 balanced by the high proportion of starch in another, such as potato or rice ; 

 or of fat in another, such as butter. Part II. will deal more at length with 

 this matter of the constituents and combinations of foods in common use, but, 

 just in passing, mention may be made of another interesting fact namely, 

 that after the first two or three years of life, the nutritive substances in milk 

 and soup are better absorbed when bread is eaten with them than when 

 taken alone. 



Another factor of physiological importance must not be overlooked; it 

 is that of 



INDIVIDUAL TASTES OR DISLIKES IN FOODS. 



This is a matter which materially influences the absorption of food. 

 There is profound truth in the old saying that " One man's meat is another 

 man's poison." The food which makes your mouth water, for instance (a 

 good omen for its digestion, by the way), may leave mine unaffected or even 

 seem to parch it up, so objectionable to me is your favourite dish. 



Eggs are actual poison to some luckless individuals, just as mutton occa- 

 sionally produces nausea in others, or shell-fish may be the cause of nettle-rash. 

 A sufferer from severe asthma has been known to enjoy freedom from this 

 distressing complaint after a supper of lobstar salad, while tortured for hours 

 after a meal of boiled fish. Generally speaking, food hated is food wasted. 



Food has been compared by one writer to ore, and the nutrients it contains 

 to the precious metal concealed within the ore. Digestion is the process by 

 which the body secures these hidden treasures. The chemical test tells us 

 how much metal is present in a given mass of ore. The physiological test 

 shows whether the body possesses the machinery or tools necessary to extract 

 and utilize it. 



