THE ALUMNI JOURNAL. 



NON - NITROGENIZED ALIMENTARY SUB- 

 STANCES. 



These are the starches, the sugars and 

 the fats. 



The starches and sugars are called 

 carbo-hydrates, because they contain H. 

 and O. in proportion to form H 2 0. 

 Starch C 6 H 10 O 5 . 



Cane sugar C 12 H 22 0„ = (Saccharose.) 

 Milk sugar C 12 H w 12 = (Lactose.) 

 Grape sugar C 6 H 12 (i = (Glucose.) 

 Starch undergoes a vast number of 

 changes according to the chemists. But 

 for our purpose it is sufficient to know 

 that all starches and sugars are converted 

 into glucose in digestion, and are taken 

 up in this form by the blood. 



The fats are stearine, palmatine and 

 oleine! They are called hydro-carbons, 

 and do not contain H and O in propor- 

 tion to form H 2 0. 



The hydro - carbons undergo various 

 changes in digestion, but these are chiefly 

 mechanical. 



The digestive fluids ultimately convert 

 them into an emulsion, and they are taken 

 up by the lactols and emptied into the 

 blood. 



The hydro-carbons are the elements of 

 diet, chiefly concerned in the production 

 ol animal heat. 



This accounts for their being the main 

 article of diet in the arctic regions. 



I will mention here a few articles that 

 retard the waste of tissue. They are 

 alcohol, tea and coffee. Still they should 

 never be taken to the exclusion of ordi- 

 nary articles of alimentation in health. 

 Alcohol is one of the most useful agents 

 at our command in the treatment of 

 wasting diseases. But should never be 

 indulged in in health. 



This is a physiological, not a social 

 opinion. 



The amount of food necessary for the 



average man under the ordinary condi- 

 tions of exercise is : 



Meat 163 



Bread 193 



Butter ( fat )3}4 3 10)923 



H 2 543 5K =6) 140 = 



24 days about. 



The digestive apparatus consists in a 

 general way of the mouth, the stomach 

 and the intestines. 



The digestive fluids are : 



1. Saliva secreted by the salivary 

 glands. 



2. The gastric juice, secreted by the 

 glands in the walk of the stomach. 



3. The pancreatic juice, secreted by 

 the pancreas. 



4. The bile which comes from the 

 liver. 



5. The intestinal juice. 



I shall take these up in the order men- 

 tioned, and show their action on the 

 various articles of diet as I go on. 



Digestion in the mouth is in part me- 

 chanical and in part chemical. 



Food is masticated by the teeth and 

 is otherwise prepared for deglutition by 

 insalivation, and the introduction of par- 

 ticles of air into its mass to allow of 

 easier access to all of it by the gastric 

 juice. 



Although there are several glands in 

 the region of the mouth that contribute 

 a share to the salivary fluid, during the 

 action of this fluid on foods, saliva is a 

 mixture, and we shall consider it as 

 such. 



Mixed saliva is opalescent, viscid 

 has a specific gravity 1,004 to 1,008. 

 It is alkaline in reaction. The quan- 

 tity secreted in 24 hours is about 45 

 oz., one third during mastication. It 

 contains a peculiar ferment called ptya- 

 line, that exists in proportion of 1.34 

 parts per 1,000. This ptyaline is conven- 

 ient in converting starch into glucose. It 

 does not convert all the starch into glu- 



