PROCEEDINGS OF THE FARMERS' CLUB. 143 



b'ecanse it contains so krge a percentage of nitrog-en, being infinitely 

 more than is discovered in the solid evacuations. With tliis knowledge, is 

 it not shameful in farmers to permit it to escape from their stables and 

 cow sheds, to form aiaimonia elsewhere only to fly into the air for the en- 

 richment of some neighboring farm ? It is inexcusable for a farmer not to 

 employ all the matters on his farm containing nitrogen, particularly those 

 in the shape of animal excrements, in his compost heap, and as these mat- 

 ters are constantly emitting carbonic acid gas and ammoniacal substances, 

 as h)ng as they contain nitrogen, he must cover the heaps with muck, or 

 charcoal dust, which will absorb and retain them as they rise. The am- 

 monia contained in manure placed upon the soil, is imbibed by it either in 

 the fcrm of gas or in solution in water, and. thus plants receive a larger 

 portion of nitrogenous compounds than is usually afforded them by the 

 surrounding air. The object of orchard culture, if that be the farmer's 

 taste, is to produce as much carbon as possible to form woody fibre ; if 

 field culture, to add as much nitrogen, in the form of ammonia, as the 

 plant can possibly absorb. 



MANURES OBTAINED BT THB DBCOMPOSITION OF FOSSIL SUBSTANCES. 



Matters that are to be considered under this head, when composted, pro- 

 duce more or less powerful effects in promoting the growth of vegetable 

 crops, according to the state and quantity in which they are applied, the 

 nature of the soils on which they may be employed, and the properties of 

 the matters with which they are combined; notwithstanding these matters 

 have been long used, still there are some difiiculties to be overcome con- 

 cerning the manner of their operation. It has been found that where mag- 

 nesia is in union with calcareous matter, it is by no means so beneiicial as 

 a promoter of vegetation, as where no such combination is present, par- 

 ticularly when used in the same proportions. If we obtain lime from dif- 

 ferent lime stones, shell, corals, or chalk, though it may be apparently of 

 the same quality, still its cflbcts will vary^very much when employed in 

 agriculture. Lime often, when placed in a compost heap in its pure 

 caustic state, in large quantities, retards the process of putrefaction, which 

 it was intended to hasten, and still when used upon the land destroys 

 snails, worms, slugs, grubs and insects, which abound in rich soils, and 

 thus they are made to furnish much nutritious matter for the growth of 

 vegetation. And from its having a tendency to combine with mucilagi- 

 nous oily matters to a greater degree than with fixed alkalies, a kind of 

 Boap is sometimes formed that probably contributes in its liquid state to 

 the nourishment of plants. The states of chemical combination in wliich 

 lime may b(^ applied to the compost heap, are as quick lime precisely as it 

 comes from the kiln, uucombined with either water or carbonic acid gas. 

 Hydrate of lime iu which it has been made to combine with one quarter of 

 its weight of water. In both these states it is caustic lime. Spontane- 

 ously slaked lime in which one part is combined with water, and the other 

 with carbonic acid gas and carbonate of lime, which is the state in which 

 it occurs in nature and to which burned lime, after a certain period, arrives. 

 Bi-carbonate is a fifth state of combination, when it is combined with a ' 

 double proportion of carbonic acid gas, and is partially soluble in water. 



Magnesian limes may also be in the state of calcined magnesia, of hy- 



