250 CROPS. XI. 



Thus though the loss in albuminoids is very small the dimi- 

 nution in digestibility is serious. The authors suggest that 

 silage should only be made of fodder comparatively low in 

 albuminoids and that clover and other highly nitrogenous crops 

 should be either used as pasture or made into hay. 



The table on pages 251, 252, and 253, containing the results 

 & of American investigations, may be useful." The figures in 

 %.the last three columns, giving the percentage amounts of 

 -(valuable manurial constituents, have evidently not been de- 

 rived from the analyses of the same samples which yielded 

 thtother numbers, as there are numerous cases in which the 

 results are inconsistent. 



A few remarks about the usual method of analysing crops 

 and other food stuffs may here be given. Almost all analyses 

 of food which have been published until quite recently were 

 made by a method introduced by Henneberg in 1864, generally 

 - known as the " "Weende" method. According to this method 

 the constituents are reported as 



Water. 



Proteids or nitrogenous matters. 



Fat or ether extract. 



" Nitrogen-free extract " or " soluble carbohydrates." 



Crude fibre. 



Ash. 



The water and ash are determined by general methods, the 

 nitrogenous matter by a determination of the total nitrogen and 

 multiplying this by 6*25, and the "fat" by ether extraction. 

 The " crude fibre" is then determined by treating a portion of 

 the sample from which the fat has been extracted with boiling 

 dilute sulphuric acid (containing 1-25% real acid) for half an 

 hoar, washing the residue until free from acid, and again 

 boiling for half an hour with a solution containing 1'25% of 

 sodium hydrate. The whole is then filtered and the residue 

 thoroughly washed, dried at 110, and weighed. The residue 

 is next completely "incinerated, when the loss of weight gives 

 the " fibre." 



* Bulletins Xos. 11 and 15, Office of Experiment Stations, U.S. Dept. of Agriculture. 



