82 BOARD OF AGRICULTURE. [Jan., 



use for ammoniating superphosphates, as fish and blood are used, 

 unless the price of the manufactured article is reduced considera- 

 bly on that account. 



The other article is leather. 



The process of tanning is designed to make the nitrogenous 

 matter of the flesh or hide just as insoluble and just as impervious 

 to water as it can possibly be. For a fertilizer, we require that 

 our nitrogenous matters shall be just as freely soluble and just as 

 easily soaked by water as can be. It is as clear as day then that 

 the waste product of the leather business is not one which is of 

 the least value to the farmer in its original condition, and experi- 

 ments with fresh and roasted leather prove this. 



Of late, a process has been put in operation of this kind. 

 Leather scrap from the shoe factories is first extracted with 

 benzine. This yields an oil which can be used for a leather dress- 

 ing, and in sufficient quantity to pay for the extraction. The 

 leather is then roasted and ground and is ready for market, to be 

 used in ammoniating superphosphates. 



The physical condition of this product is excellent. It is dry 

 and fine. It- is claimed too that a considerable portion of the 

 tannin, the preservative principle, is destroyed by roasting. How- 

 ever that may be, it is quite certain that a good deal is left un- 

 hai'med, and theoretical considerations make it appear quite proba- 

 ble that the nitrogen is in a form not available for plants. 



Practical trials made by Prof. Petermann in pots, in the garden 

 and on larger field plots with oats, beans, and sugar beets, gave no 

 inci'ease over theunmanured parcels in the case of beans, and only 

 a slight increase in the other cases, while dried blood or Chili 

 saltpeter caused a very considerable increase in the yield. 



While the farmer should welcome the appearance of any waste 

 product which promises to be of service to him as a fertilizer as 

 bone, blood, and fish scrap have been, it should be understood that 

 he is not going to carry off every waste thing which no one else can 

 use unless it is in just such a shape as will make it pay for him to 

 take it. It is possible that, in time, a valuable fertilizer can be 

 made from leather chips. It is certain that it has not been done 

 yet, and the presence of leather in a superphosphate must at 

 present excite distrust of its value. 



A comparison of samples of dried blood and ground leather, 

 shows how much alike they are in appearance, and when mixed in 



