140 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



proportion of mucilag'inous or gelatinous matter, a slight proportion of 

 fat, and an earthy salt composed of the phosphoric acid and calcareous 

 earth. When heat is applied to them they afford a large quantity of car- 

 bonic acid gas, hydrogen gas, and a volatile alkaline liquor. From the 

 nature of these different principles, it is evident that they are capable of 

 promoting an admirable effect when mixed with vegetable mould in the 

 compost heap, by forming new combinations highly favorable to the process 

 of vegetation. The usual mode of consuming bony substances, by means 

 of fire, for the purpose of obtaining their ashes, is a wasteful practice 

 which ought not to be attempted by farmers, as by it the oily materials 

 are driven off, and nothing remains but phosphate of lime. Compound 

 manures, or those combined with different substances that are capable of 

 being made use of as enrichers, may be mixed and blended with each 

 other, or with substances of other kinds, and by such means be increased 

 in quantity, besides being rendered more suitable and effectual for appli- 

 cation than m their simple states. The general experience of farmers has 

 fully shown the great utility and importance of employing compound ma- 

 nures, or composts. Farm yard manure, which is the most general appli- 

 cation of any, from its being formed by the decay of various kinds of vege- 

 table matters, such as hay, straw, cornstalks, and other materials of a like 

 nature with which the urine and dung of animals is combined and incorpo- 

 rated, must be considered as a compound substance. But from most of the 

 vegetable materials being made use of in a hard and dry state, they do not 

 so quickly ferment or run into the state of decay, notwithstanding the 

 proportion of animalized matters that may be incorporated with them. It 

 therefore becomes a useful practice to turn them over, by which their com- 

 plete putrefaction may not only be promoted, but the different materials be 

 more minutely blended together, on both which accounts they may become 

 more useful when applied as an enricher to land. Where animal matters 

 are collected and thrown together in any quantity, there can be but little 

 doubt but that a great increase of good manure may be provided by misr 

 ing with them rich surface mould, peat earth, or the scrapings of roads ; 

 by Buch a practice the ammonia formed during the decomposition of anir 

 mal substances is prevented from escaping, as would otherwise be the 

 case, which combining with and acting upon the earthy materials, quickly 

 renders them proper for the purposes of manure. As substances of thp 

 animal kind run very rapidly into the state of putrefaction, they may often 

 be incorporated with such vegetable materials as are little disposed to rot 

 or become putrid, and by such means useful composts may be expeditious- 

 ly formed. Earthy materials may be made use of to a great extent, where_ 

 the manure to be mixed with them is of the animal kind. The following 

 table of manurial substances shows the number of loads of dry, or moist 

 manures that is required to equal one hundred loads of barn-yard, so far 

 as the quantity of nitrogen they contain is concerned : 



Wheat straw dry, 600 wet, 160 



Rye " " 915 " 240 



Oat " " 550 " 140 



Barley " " 740 " 165 



Potato tops " 85.... " 70 



