NITROGEN IN AGRICULTURE. 185 



11.81 per cent nitrogen ; if steamed and then ground, the nitrogen 

 the}' contain becomes, in a degree, available. Wiien used to adul- 

 terate superphosphate, as they very rarely are, being ground up, 

 the particles can be readilv detected by the microscope. Horn- 

 waste is mostly' in thin, bulky shavings, which are marketed in 

 huge bags. Several years ago I purchased a ton to test its avail- 

 abilit}- and value, not having anj' idea of the peculiar mechanical 

 condition of the article. Standing at m}' door one morning I saw 

 a team coming down the street, with a bulk of bags piled as high 

 as a large load of hay. While I was wondering what new product 

 had come to town, the driver stopped abreast of my house, and 

 told me he had a ton of horn-waste bearing my address. I got rid 

 of this elephant the shortest and easiest wav, b}' tumbling it into 

 the manure cellar, and throwing the daily manure upon it until it 

 disappeared from view. My men found combs, more or less per- 

 fect, among the mass, enough to supply their families for a year or 

 more. This stuff is verj^ rich in ammonia ; but, though by la3'er- 

 ing it witli horse manure, it might be softened and dissolved by 

 fermentation, it is nevertheless so bulky that, even at a low figure, 

 few farmers would care to invest in it. Leather scraps are an ex- 

 cellent material for mulching, and in time will decay and fertilize 

 the ground ; but if worked into tillage land they are a nuisance. 

 They are also excellent for covering blind drains. I have seen 

 drains put down thirty 3'ears ago, and then covered with this mate- 

 rial, which are still in good working order. 



In closing this subject I cannot do better than to quote the able 

 remarks of Professor Goessmann : " The air contains at all times 

 carbonic acid, and in most instances also nitric and nitrous acid 

 and ammonia. The soil absorbs continually more or less of the 

 former, and receives the nitrogen compounds in rain and snow. 

 Once absorbed by the soil the}' find access to the plant by the 

 roots, as carbonates and nitrates, where the}' assist in the forma- 

 tion of the organic portion of the plant. Besides this direct sup- 

 port of plant growth they serve, also, the very important purpose 

 of increasing the supply of inorganic plant food; for they aid in 

 the disintegration of the soil." 



Discussion. 



Mr. Gregory said, in reply to an inquiry, that he used niti'ogen, 

 in the various forms of which he had spoken, on vegetables ; he 



