On evaporating the water-solution to dryness and heating strongly in a China cup, a vitriol peat gives off white choking fumes of sulphuric acid, and there remains, after burning, brown-red oxide of iron in the dish.
The above testings are easily conducted by any one, with the ordinary conveniences of the kitchen.
Those that follow, require, for the most part, the chemical laboratory, and the skill of the practised chemist, for satisfactory execution.
Besides testing for soluble iron compounds, as already indicated, the points to be regarded in the chemical examination, are:—
1st. Water or moisture.—This must be estimated, because it is so variable, and a knowledge of its quantity is needful, if we will compare together different samples. A weighed amount of the peat is dried for this purpose at 212° F., as long as it suffers loss.
2d. The proportions of organic matter and ash are ascertained by carefully burning a weighed sample of the peat. By this trial we distinguish between peat with 2 to 10 per cent. of ash and peaty soil, or mud, containing but a few per cent. of organic matter.
This experiment may be made in a rough way, but with sufficient accuracy for common purposes, by burning a few lbs. or ozs. of peat upon a piece of sheet iron, or in a sauce pan, and noting the loss, which includes both water and organic matter.
3d. As further regards the organic matters, we ascertain the extent to which the peaty decomposition has taken place by boiling with dilute solution of carbonate of soda. This solvent separates the humic and ulmic acids from the undecomposed vegetable fibers.
For practical purposes this treatment with carbonate of soda may be dispensed with, since the amount of undecomposed fiber is gathered with sufficient accuracy from careful inspection of the peat.
Special examination of the organic acids is of no consequence in the present state of our knowledge.