1895.] PUBLIC DOCUMENT — No. 33. 285 



The chemical composition of the above fertilizing ingre- 

 dients can be ascertained from the table on page 277. The 

 Philadelphia tankage contained seven and one-half per cent, 

 nitrogen. 



October 2, crops were planted in the boxes as follows : — 



Boxes 1 and 2, winter rape. 



Boxes 3 aud 4, winter vetch. 



Boxes 5, 6, 7, 8, 9 aud 10, wiuter rye. 



The seed germinated well and the plants made a good 

 growth before winter, being left in the cold house and cov- 

 ered with snow during the wiuter season, to imitate as nearly 

 as possible the outside conditions. 



."). Leather Refuse, — its Value in Aokiculture.* 



Bt J. B. LiNDSEY. 



During the past few years claims have been made at 

 various times that large quantities of leather shavings and 

 the like have found their way into the so-called commercial 

 fertilizers that are so widely used by the farmers of the 

 United States. The writer has no means of knowing 

 whether this claim is true or not. It should be the object 

 of the fertilizer manufacturer to utilize all kinds of waste 

 products that possess distinct manurial value. By so doing 

 he not only benefits himself, l)ut the farmer as well. 



It was very early assumed from its chemical character, 

 without any exact experiments upon which to base the 

 assumption, that leather refuse would yield its nitrogen as 

 plant food very slowh', if at all. 



/. Historical JRevieiv. 

 1. Methods employed to make the Nitrogen available to Growing 



Plants. 



The first method suggested, so far as the writer has been 

 able to ascertain, was that prescribed by F. O. AVard f of 

 England, in 1857, for turning to account woollen rags, 



* A portion of this article has already appeared in Agricultural Science, Vol. 8, 

 Xos. 2 and 3, 1894. 



t Report by the Juries of the International Exhibition, 1862. Reporter, A. W. 

 Hoflfman. Repertory of Patent Inventions, August, 1857, page 137. 



