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The aim of alimentation is to supply the animal economy with the 
principles it requires for the production of its energy, and with the 
primordial elements which directly or indirectly go to the repair or 
growth of tissues. The more an aliment contains of these elements 
in quality and quantity, the greater is its nutritive value. 
In the admirable paper read before you last year, your worthy 
vice-president has made you acquainted with the principles which con" 
stitute the chemical composition of our body. Here they are briefly 
enumerated : Oxygen, hydrogen, nitrogen, carbon, sulphur, phosphorus, 
calcium, sodium, potassium, magnesium, chlorine, iron and fluorine. 
These elements are found in various combinations with one another 
and form nitrogenous and non-nitrogenous compounds, carbo-hydrates 
and salts. They enter into the composition of all the tissues of the 
body. Since food is destined to the rebuilding of those tissues, it is 
evident that the ideal aliment, the perfect type, would be the one into 
the composition of which would enter in the meantime, all the chemical 
elements I have enumerated. But that ideal does not exist. There 
are, for example, nutrients which contain a considerable proportion of 
nitrogen, making them eminently proper to repair the tissues, but which, 
on the other hand, possess too small a quantity of carbo-hydrates to 
meet the wants required by respiration and the production of animal 
heat. Others, while they are rich in carbon and hydrogen, are very poor 
in azote. Hence, the necessity of a mixed alimentation to properly 
supply nutrition with all its requirements. 
Formerly, primordial foods were divided in two classes, namely : 
the plastic and the respiratory aliments. 
The plastic aliments were constituted by albuminous substances to 
which the name of quaternary was given, because they possessed a more 
or less great number of atoms of oxygen, hydrogen, carbon and 
nitrogen. They were found in almost all the tissues and fluids of the body, 
forming the base of muscular tissue, gelatine of the bones, fibrin of the 
blood, casein of the milk, albumen of the egg, gluten of the bread, etc., 
etc. Respiratory aliments, so called because they are used for respira. 
tion and are consumed in the body, formed the base of tats, sugars and 
feculents. 
For this altogether theoretical division, we have nowadays substitute 6- 
