14 



A CHEMICALLY PERFECT FOOD MAY BE IMPOSSIBLE OF 



DIGESTION 



or otherwise unsuitable to the consumer; consequently, great importance is 

 attached by competent authorities to the three other tests just mentioned. 

 The second of these, namely, 



THE PHYSICAL TEST FOR FOOD-VALUES, 



will now be discussed. To enter intelligently into the worth of this test 

 readers must be reminded of Professor Chittenden's three great mysteries of 

 life: (1) The power of the body to grow at the expense of the food eaten; 

 (2) the power to renew the worn-out parts of the body by the utilization of 

 the daily diet; and (3) the power to derive energy from this supply to run 

 the machinery of the body, and thus to work. 



HOW IS THIS ENERGY DERIVED FROM FOOD? 



An engine derives energy from the steam generated by the water in its 

 boiler, which is heated by the combustion of fuel in its furnace. We con- 

 stantly talk, too, about the body's furnace and how it is stoked by the fats 

 and carbohydrates present in the food we eat; but all the time we realize 

 that what we say is. after all, but a figure of speech. Nevertheless, food does 

 seem to warm us up on cold days, when we thoroughly enjoy suet puddings, 

 hot buttered toast, or pork and beans; whereas in warm weather we instim 

 tively turn from these foods and choose fruit, custard, and sponge-cake. 



To take another example of what our sensations teach as to the 

 connection between food and energy. Every one has noticed that, when 

 wearied by a long spell of work, 



A GOOD MEAL REVIVES US AMAZINGLY 



and restores our flagging energies; and we have all experienced at some 

 time or another that when very hungry, even pleasures lose their savour; 

 but soon after taking food a sensation of refreshment is felt and we resume 

 our work or play with renewed zest. There can be no doubt that 



FOOD AND ENERGY ARE CLOSELY CONNECTED. 



Yea, more than this, food -its sufficiency or deficiency can and does 

 affect the character and direction of the actions by which energy is outwardly 

 expressed. Have you ever heard that 



THE TERRIBLE EXCESSES OF THE FRENCH REVOLUTION 



may be attributed to brains disordered by starvation? By one of life's 

 perplexing ironies, this poor, starved people actually guillotined, in their 

 misdirected energy, the great founder of modern chemistry, Lavoisier, who. 

 before his execution in 1794, had fortunately set men on the right road to 

 discover the character of the changes undergone by food in the body, which 

 result to the eater in a supply of energy for work. 



Since the days of Lavoisier, the process he dimly perceived has been 

 clearly traced. It is now proved that these changes are brought about by 



A PROCESS OF SLOW COMBUSTION, 



technically called "oxidation," always going on in the liver and muscles. 

 The process does not exactly resemble the rapid combustion, accompanied by 



