4th. The proportion of nitrogen is of the first importance to be ascertained. In examinations of 30 samples of peat, I have found the content of nitrogen to range from 0.4 to 2.9 per cent., the richest containing seven times as much as the poorest. It is practically a matter of great moment whether, for example, a Peruvian guano contains 16 per cent. of nitrogen as it should, or but one-seventh that amount, as it may when grossly adulterated. In the same sense, it is important before making a heavy outlay in excavating and composting peat, to know whether (as regards nitrogen) it belongs to the poorer or richer sorts. This can only be done by the complicated methods known to the chemist.
5th. The estimation of ammonia (actual or ready-formed,) is a matter of scientific interest, but subordinate in a practical point of view.
6th. Nitric acid and nitrates can scarcely exist in peat except where it is well exposed to the air, in a merely moist but not wet state. Their estimation in composts is of great interest, though troublesome to execute.
7th. As regards the ash, its red color indicates iron. Pouring hydrochloric acid upon it, causes effervescence in the presence of carbonate of lime. This compound, in most cases, has been formed in the burning, from humate and other organic salts of lime. Sand, or clay, being insoluble in the acid, remains, and may be readily estimated.
Phosphoric acid and alkalies, especially potash, are, next to lime, the important ingredients of the ash. Magnesia and sulphuric acid, rank next in value. Their estimation requires a number of tedious operations, and can scarcely be required for practical purposes, until more ready methods of analyses shall have been discovered.
8th. The quantity of matters soluble in water has considerable interest, but is not ordinarily requisite to be ascertained.
6.—Composition of Connecticut Peats.
In the years 1857 and 1858, the author was charged by the Connecticut State Agricultural Society[8] with the chemical investigation of 33 samples of peat and swamp muck, sent to him in compliance with official request.
In the foregoing pages, the facts revealed by the laborious analyses executed on these samples, have been for the most part communicated, together with many valuable practical results derived from the experience of the gentlemen who sent in the specimens. The analytical data themselves appear to me to be worthy of printing again, for the information of those who may hereafter make investigations in the same direction.—See Tables I, II, and III, p.p. 89, 90, and 91.
The specimens came in all stages of dryness. Some were freshly dug and wet, others had suffered long exposure, so that they were air-dry; some that were sent in the moist state, became dry before being subjected to examination; others were prepared for analysis while still moist.