_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. A sufficient quantity of each specimen was carefully pulverized, intermixed, and put into a stoppered bottle and thus preserved for experiment. The analyses were begun in the winter of 1857 by my assistant, Edward H. Twining, Esq. The samples 1 to 17 of the subjoined tables were then analyzed. In the following year the work was continued on the remaining specimens 18--33 by Dr. Robert A. Fisher. The method of analysis was the same in both cases, except in two particulars. In the earlier analyses, 1 to 17 inclusive, the treatment with carbonate of soda was not carried far enough to dissolve the whole of the soluble organic acids. It was merely attempted to make _comparative_ determinations by treating all alike for the same time, and with the same quantity of alkali. I have little doubt that in some cases not more than one-half of the portion really soluble in carbonate of soda is given as such. In the later analyses, 18 to 33, however, the treatment was continued until complete separation of the soluble organic acids was effected. By acting on a peat for a long time with a hot solution of carbonate of soda, there is taken up not merely a quantity of organic matter, but inorganic matters likewise enter solution. Silica, oxyd of iron and alumina are thus dissolved. In this process too, sulphate of lime is converted into carbonate of lime. The total amount of these soluble inorganic matters has been determined with approximate accuracy in analyses 18 to 33.