The fitness of soil for larch seems to depend more especially upon the ability the soil possesses of affording an equable supply of moisture; that is, upon its {82} mechanical division, or its powers of absorption or retention of moisture; and its chemical composition would seem only efficacious as conducive to this. Soils and subsoils[20] may be divided into two classes. The first, where larch will acquire a size of from 30 to 300 solid feet, and is generally free of rot; the second, where it reaches only from 6 to 20 feet solid, and in most cases becomes tainted with rot before 30 years of age. CLASS I. SOILS AND SUBSOILS FOR LARCH. _Sound rock, with a covering of firm loam, particularly when the rock is jagged or cloven, or much dirupted and mixed with the earth._—In such cases, a very slight covering or admixture of earth will suffice. We would give the preference to primitive rock, especially micaceous schist and mountain limestone. Larch seldom succeeds well on sandstone or on trap, except on steep slopes, where the rock is quite sound and the soil firm. {83} Fully the one half of Scotland, comprehending nearly all the alpine part, consists of primary rock, chiefly micaceous schist and gneiss. These rocks are generally less decayed at the surface, better drained, and fuller of clefts and fissures containing excellent earth (especially on slopes), into which the roots of trees penetrate and receive healthy nourishment, than the other primitive and transition rocks, granite, porphyry, trap, or the secondary and tertiary formations of nearly horizontal strata, red and white sandstone, &c. Primary strata are generally well adapted for larch, except where the surface has acquired a covering of peat-moss, or received a flat diluvial bed of close wet till or soft moorish sand, or occupies a too elevated or exposed situation—the two latter exceptions only preventing the growth, not inducing rot. _Gravel_, not too ferruginous, and in which water does not stagnate in winter, even though nearly bare of vegetable mould, especially on steep slopes, and where the air is not too arid, is favourable to the growth of larch. It seems to prefer the coarser gravel, though many of the stones exceed a yard solid.