158 



Bile, formed in the hepatic cells, assists in the emulsification of fats 

 and promotes their absorption and stimulates the secretions ef the 

 intestinal glands. It also serves to prevent putrefactive changes in the 

 food. The digested food or chyme is absorbed by the blood as 

 the food passes through the intestines, the undigested portion entering 

 the large intestines. 



The Chemistry of Cookij^g. 



The changes induced by cooking are manifold, some increasing, 

 others decreasing the digestibility of the food, while others only serve 

 to render the same more tasteful by the production of certain substan- 

 ces which pleasantly excite the palate. 



Meats are more readily digested when ''underdone" than well 

 cooked, though undoubtedly very tough meat by its disintegration is 

 rendered more tender and easy of mastication by the process. Certain 

 empyreumatic substances are developed by roasting and boiling meals 

 which give agreeable taste and savoury odours. These act rather as 

 stimulants than nutrients, and render the food more jjalatable than in 

 the uncooked condition. Roast beef, beef tea and soups owe their 

 piquancy to these compounds. Eggs and milk are rendered less 

 digestible by cooking, for the reason that coagulated albumen is not 

 readily acted upon by the digestive fluids. 



On the other hand, most vegetable foods require cooking to in- 

 crease their digestibility, The cells containing the staich in the raw 

 material have walls of cellulose, difficult of digestion. By cooking, this 

 cellulose is softened and the starch grains are burst. The contents then 

 are more completely exposed to the digestive fluids. 



In summing up I would offer the following remarks and deductions- 

 Their importance, I think, merits your consideration. 



I. That in the choice of viands care should be taken that the diet 

 consists of both vegetable and animal foods. The proportion of 

 nutrients may roughly be stated at three times the weight of carbo- 

 hydrates to equal weights of fats and albuminoids. Excess of any one 

 nutrient is likely to be injurious to health. 



It would seem that nature teaches what science confirms — a 

 proper combination of materials. The Irishman with his potatoes 

 (carbo-hydrates) and buttermilk (albuminoids), the Englishman with 



