EXPERIMENT STATION RECORD. 



Vol. 2. DECEMBER, 1890. No. 5. 



EDITORIAL NOTES. 



The need of improvement in the methods for analysis of feeding 

 stuffs and foods and for estimating their nutritive values has been sev- 

 eral times insisted upon in the publications of this Office. At the 

 convention of the Association of Official Agricultural Chemists, at 

 Washington, Sei)tember 10-12, 1889, the subject was earnestly dis- 

 cussed, and a committee, consisting of Messrs. W. O. Atwater, G. C. 

 Caldwell, E. H. Jenkins, W. H. Jordan, and H. W. Wiley, was appointed 

 to consider ways and means for securing more thorough chemical study 

 of foods and feeding stuffs. The report of this committee, presented at 

 the meeting of the association held in Washington August 28-30, 1890, 

 will be ])ublished in full in the proceedings. The principal points 

 urged are included in the following statements. 



We make analyses of foods and feeding stuffs to determine their 

 values for nourishment, and hence the proper ways to use them. In so 

 doing we classify the ingredients in different groups, and assign to 

 each group a specific nutritive value. By our current methods we make 

 the groups practically the same for all vegetable substances, thus ignor- 

 ing the differences of kindred compounds in different plants and parts 

 of plants, and even go so far as to make nearly the same grouping for 

 animal as for vegetable compounds. We thus class compounds of 

 widely different chemical and physiological characters in the same group, 

 and frequently put into a group compounds which do not belong there 

 at all. We base our methods of analysis, of separating the ingredients 

 and determining their amounts, mainly upon two classes of properties, 

 their elementary composition and their solubilities, and yet our knowl- 

 edge of these properties is imperfect at best, and in some cases scarcely 

 suffices for more than to assure us of the incorrectness of our methods. 

 In many instances, especially with vegetable materials, the solubility 

 of the ingredients in laboratory re-agents, their digestibility in labora- 

 tory experiments and in the animal's body, and their nutritive effect are 

 dependent upon the ways in which they are held in the vegetable tis- 



185 



