EXPERIMENT STATION RECORD. 



Vol. VIII. No. 8. 



It has been recognized for a number of years tliat the nitrogen-free 

 extract of feeding- stuffs contains a variety of carbohydrates of widely 

 different chemical composition and x^i'operties and of different rates of 

 digestibility. This fact taken in connection witli the uncertain manner 

 of determining- this indefinite and variable group has created a distrust 

 of the value of such determinations, and has made it very api)arent that 

 a more radical treatment of this important group of nutrients is called 

 for by the present status of knowledge, lieference has been made to 

 the recogiution of this by the Association of Official Agricultural 

 Chemists and their determination to confine their stndies on methods 

 of fodder analysis to the perfection of methods for deternuning more 

 definite groups of constituents. 



The interest in this phase of agricultural analysis and nutrition has 

 become more and more widespread with the progress of investigation, 

 and as this research has, for the most part, been confined to compara- 

 tively few investigators and those largely in other countries, a concise, 

 systematic discussion of the nitrogen-free extract, its constituents, their 

 determination, nutritive value, etc., and its relation to other groups of 

 constituents, has seemed desirable. Such a resume by the leading- 

 spirit in these investigations is presented in this number of the Itecord. 

 Professor Tollens has a world-wide reputation for his research on the 

 carbohydrates occurring in nature, and has given close study to this 

 group of constituents in their relation to methods of analysis and to 

 feeding. It is believed that tlie bringing together of the information 

 on this subject from various sources and the treatment of it in its rela- 

 tions to the methods of analysis and research in nutrition will be help- 

 ful to all, and especially to those who have not followed the literature 

 systematically. 



In his papier Professor Tollens points out the deficiencies and the 

 advantages of the Weende method, and gives a somewhat historical 

 account of its development. One point which he makes very plain is 

 that Professor Henneberg, the originator of the method, understood 

 and recognized its weaknesses quite as well as those who have since 

 criticised it freely. Furthermore, Professor Henneberg urged caution 



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