Tin-; CKRKALS. 33 



exact method. As the author of the present Handbook was 

 the first chemist who devised an analytical method for dis- 

 tinguishing between albuminoid and non- albuminoid nitrogen 

 in foods, he may be permitted to add that exaggerated deduc- 

 tions have been made in some published works on food and 

 dietetics for non-albuminoid nitrogen. And he would further 

 urge that, as many theoretical or standard dietaries have been 

 constructed in part upon the old and incorrect data as to the 

 albuminoids in the foods consumed, such dietaries may be 

 not unfairly imitated by the use of analytical results obtained 

 in the same, that is, the usual way. It would occupy too 

 much space were all the evidence in support of this argument 

 to be marshalled before our readers ; but, taken in connection 

 with the other reasons we have urged, we think it justifies the 

 course we intend to follow in the present elementary Handbook. 

 There is good reason to conclude that the albuminoids of 

 the cereals, while presenting, if pure, very slight variations in 

 the proportions of their ultimate chemical elements, exist in a 

 number of states or modifications. The so-called "gluten" of 

 wheat may be resolved into three or possibly four constituents ; 

 two of these occur in maize, where they are accompanied by a 

 third albuminoid not found in wheat and called "zein." These 

 are not products obtained by the chemical treatment to which 

 the wheaten flour and maize flour are submitted in the processes 

 of extraction they are edncts pre-existing in the raw materials 

 operated upon. The properties of these, and other members 

 of the group of cereal albuminoids, are probably identical in one 

 respect only, namely, their value as nutrients ; their distinctive 

 physical and mechanical properties are certainly in many cases 

 well marked. Thus (as is stated on page 32) it is upon the 

 peculiar elastic and viscous character of the chief albuminoid of 

 wheai-grain, the gluten-fibrin, that its admirable appropriateness 

 for the making of a light vesiculated bread depends. It may be 

 here observed that those valuable mineral salts, the alkaline and 

 earthy phosphates, are very intimately associated with the 

 albuminoids, although tho union can hardly be regarded as a 



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