400 



SCIENTIFIC AGRICULTURE 



August. 1922 



The Vitamins and their Relation to Animal 



and Plant Nutrition 



By Dr. A. BRUCE MACALLUM 



Synthetic Drug Company 

 Toronto, Ont. 



(Abstract of two lectures delivered 



The vitamins comprise a group of com- 

 pounds which are essential for the orderly 

 regulation of the animal metabolism. Their 

 function is not, as with the ordinary ele- 

 ments of the diet, concerned with the provi- 

 sion of energy and tissue repair but with 

 the regulation of the metabolism of the fats, 

 carbohydrates, lime and phosphorus in some 

 manner as yet unknown. They owe their 

 discovery to the fact that certain pathologi- 

 cal changes appear in the animal organism 

 when it is forced to subsist on diets low or 

 totally defective in these essential factors and 

 subsequent research has defined a series of 

 abnormal states known as "Deficiency Dis- 

 eases" which follow the consumption of a 

 vitamine free diet. 



Three members of the vitamin group have 

 been definitely identified. These are known 

 as the Fat Sbluble A, the Water Soluble B 

 or antineuritic factor, and the C or antiscor- 

 butic compound. These elements are in all 

 probability organic compounds of a simple 

 structure, since two are dialysable and all 

 have the property of exerting their functions 

 when present in the most infinitisimal traces. 

 Indeed, the amounts usually present in food 

 stuffs is so small that it has been impossible 

 to economically concentrate a sufficient 

 amount of material to yield quantities 

 sufficient for modern methods of analysis. 

 One property common to the series is that 

 the physiological activity of the members of 

 the group can be partially or totally de- 

 stroyed by the action of heat, oxygen and 

 the alkaline ranges of reaction of solvent 

 media. This destruction is probably not 

 brought about by decomposition of the mole- 

 cule itself but by an isomeric change taking 

 place and an inactive form resulting from 

 the operation of these various adverse factors. 

 Finally there are no chemical methods by 

 which the individuals or the group can be 

 identified and recourse must be had to bio- 

 logical methods of the type of feeding exper- 

 iments for their detection. 



The antineuritic vitamin was the first mem- 



at the C. S. T. A. Convention) 



her of this group to be isolated as a distinct 

 factor and was the result of observations upon 

 beri beri, a disease endemic in Asiatic rice 

 consuming nations. It was known for some 

 years previous to this that this condition 

 did not arise when unmilled rice was con- 

 sumed and that the preventive factor was 

 located in the millings which contained the 

 germ, bran and aleurone layer of the rice 

 grain. The production of experimental beri 

 beri upon fowls by Eykmann opened up this 

 new field and led to important discoveries as 

 to the nature of the curative substance. 



The water soluble factor has subsequently 

 been found in other food stuf-fs than rice. It 

 is present in the germ and aleurone layer 

 of all cereal grains, and in cattle products 

 such as milk, egg-yolk, and butter. It is 

 found in small quantities in the muscular 

 tissue of stock animals. The compound it- 

 self is water soluble, dialysable and insolu- 

 ble in practically every organic solvent, but 

 it can be dissolved in alcohol water mixtures 

 up to 90 per cent, alcohol. It is probably 

 basic in nature since acid solutions promote 

 the extraction. It will withstand the action 

 of fairly concentrated sulphuric and hydro- 

 chloric acids even where these are boiled 

 for some hours without depreciating its pro- 

 tective function. Solutions whose reaction is 

 faintly acid will retain their activity at room 

 temperature for weeks but will lose their 

 antineuritic properties when autoclaved at 

 120"C. for a few hours and partial loss takes 

 place at temperature ranging from 100-120" 

 C. If the reaction of the solution is alkaline 

 the functional activity tends to disappear at 

 temperatures from .jO-100"C. The natural 

 food stuffs can be stored indefinitely with- 

 out appreciable loss of antineuritic power. 

 Various attempts have been made to separate 

 it by the use of the alkaloid reagents but 

 phospholungstic acid and a combination of 

 silver nitrate and baryta are the most effect- 

 tive means of getting an insoluble metal salt. 

 A ))reparation with extremely potent cura- 

 tive power lias been prepared in this way 



