1201. The presence of salt, sulphur, coal, &c., may be known by the absence or peculiarity of vegetation, as well as by colour, and the appearance of the water of such soils. Saline soils may be distinguished by the taste; sulphureous soils by their smell when thrown on a hot iron; and the presence of coal by its fragments, which will be left after the soluble matters are removed by water and muriatic acid.