FERTILIZERS. 57 



serve as a strainer or filter. These two bottoms of the tank have each a larger opening, 

 which is closed by a long stick fitting into them, and reaching to the surface of the tank 

 which is used to discharge the liquid that has passed through the strainer, after the treat 

 ment of the blood has been accomplished. A steam-pipe passes down to the filter, which is 

 controlled by a valve. The steam is then turned on and remains so for an hour or more, which 

 heats the blood and changes it into a coagulated mass that collects upon the filter or strainer 

 after the liquid at the bottom has been discharged. It is afterward dried by steam and pul 

 verized for the market. This substance will contain, when pure, from 10 to 16 per cent, of 

 nitrogen. The amount of nitrogen lost by discharging the liquid is very slight, amounting 

 to only about one-half of one per cent. 



Animal Dust. This fertilizer is prepared from the blood, meat, scraps, and a part of 

 the bones obtained from large slaughter-houses, some of which, in the vicinity of Boston, are 

 large enough to dispose of three hundred head of cattle and two thousand sheep per day, 

 and the daily production of the fertilizer made from the refuse is equal to about six tons. It 

 is made by the meat scraps and smaller bones being passed through the rendering process to 

 secure the fat ; the refuse matter is then mixed with blood and dried by steam heat. When 

 properly dried and ground to a powder, it furnishes a good fertilizer, which is easily decom 

 posed and assimilated by the plants, and is said to be a good substitute for Peruvian guano. 

 Of course, this material varies in its composition and value, and is, like most other commodities 

 in the market, susceptible of adulteration, but the following table from an authentic source, 

 giving the analysis of this article manufactured by a reliable firm, will show about what its 

 average fertilizing properties should be : 



ANIMAL DUST. 



Per Cent. 

 Volatile and organic animal matter, .... 71.00 



Ash constituents, . . . . . . . 28.90 



Moisture, ........ 11.50 



Phosphoric acid in ash, . . . . . . 11.26 



Nitrogen in organic matter, . . . . . . 6.84 



Insoluble matter, ....... .56 



Most of the blood and refuse of the large slaughtering establishments in the Eastern 

 States are used for making this manure. 



Cotton Seed, Castor, and Linseed Pomace. The pomace left after expressing 

 the oil from .cotton-seed, linseed, castor beans, etc., is rich in nitrogen, and can be made very 

 profitable for fertilizing the soil, when of a suitable texture, since the finer the texture, the 

 more easily is it decomposed to become available plant-food. Prof. White, of Georgia, in 

 his treatise on the &quot; Complete Analysis of the Cotton-plant,&quot; states that the ashes of the hulls 

 of the cotton-seed contain fourteen per cent, of potassium oxide, and seven per cent, of phos 

 phoric acid. Cotton-seed furnishes a valuable ingredient to the compost pile, but when taken 

 whole will become most readily reduced and the hulls broken up by first being fermented by 

 having the seeds well wet and mixing with hard-wood ashes, in the proportion of about 360 

 pounds of seed to four bushels of ashes. This should be kept well wet until thoroughly 

 fermented, as described under the heading of Composts. It is conceded by the best agricul 

 turists, as a general rule, that the waste material of any farm -crop pays best when used upon 

 the same field which served for its production, and that this is especially true in case of the 

 industrial products where a frequent reproduction of the same crop becomes a leading feature 

 of the farm management. In this way, the elements extracted from the soil in the production 

 of certain crops are in a measure restored, and exhaustion of soil prevented. 



Fish, Fish Guano, Fish Pomace, etc. Fish have long furnished manure for 

 agricultural purposes to this and other countnes, and will probably continue to be one of the 

 chief sources of supply for the future, since it is rich in phosphoric acid and nitrogen, two 



