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Even prior to this date scientific workers clearly indicated that 

 factors were present in food other than carbohydrates, fats and 

 proteins. Within the last five years interest in vitamins has be- 

 come widespread and the general public have many questions that 

 they want answered. The book by Dr. Eddy, long a worker in 

 vitamin research, answers these questions in a straightforward 

 manner. Scientific accuracy has been maintained throughout the 

 volume. 



Vitamins are intimately tied up with plants for in nature these 

 organic chemical compounds occur in natural foodstuffs. The ad- 

 vance in vitamin knowledge occurred when these substances were 

 isolated in pure form and their chemical structure determined. With 

 definite chemical entities science could determine their function and 

 role in living organisms. Many of these substances have been made 

 synthetically in the laboratories. Twelve vitamins have been chem- 

 ically identified and their functions clearly demonstrated. 



The author indicates the method of naming the vitamins and 

 explains their chemical nature in a carefully selected appendix. 

 The information about vitamins is understandable to one who may 

 not have a great deal of technical knowledge. Throughout the book 

 the painstaking research that was necessary to bring order out of 

 chaos is vividly described. 



A considerable number of vitamins have been postulated on 

 the physiological reactions that they show. These substances have 

 not as yet been isolated or determined chemically. Included in this 

 group are the anti-grey hair factor, Centanni's digestive factor, 

 the grass juice factor and about a dozen other factors. Their role 

 in human economy can only await the results of further research. 



For proof of vitamin activity one only has to compare a 

 picture of a group of school children of 1900 and 1940. It is clearly 

 established that certain vitamins must be present in food or given 

 otherwise if we are to prevent rickets, scurvy, pellagra and other 

 existing deficiencies. Certain facts are still lacking on how the 

 vitamins are able to protect an individual from these conditions. 

 In one chapter the relation of certain of the vitamins to intra- 

 cellular respiratory enzymes is introduced. The processes of 

 oxidation, hydrogen carriers, coenzymes, cytochromes and car- 

 boxylases are explained so as to give one an idea of how some of 

 the vitamins function in cellular activity. 



