CHAP. CXI II.

coni'ferje. /.a'rix.

2377

air of the hill refreshing and nourishing the plant during the summer heats,and compensating for the dryness of the soil ; 5. the reverberating of the sun’srays between the sides of the narrow valley, thus rendering the soil compara-tively warmer than the incumbent air, which is cooled by the oblique currentsof the higher strata of air, occasioned by the unequal surface of the ground.This comparatively greater warmth of the ground, when aided by moisture,either in the soil or atmosphere, is greatly conducive to the luxuriance ofvegetation.

“ 3. Firm dry Clays, and sound brown Loam . Soils well adapted for wheatand red clover, not too rich, and which will bear cattle in winter, aregenerally congenial to the larch.

“ 4. All very rough Ground, particularly ravines, where the soil is neithersoft sand nor too wet; also the sides of the channels of rapid rivulets. Theroots of most trees luxuriate in living or flowing water; and, where it is ofsalubrious quality, especially when containing a slight solution of lime, willthrow themselves out a considerable distance under the stream. The reasonwhy steep slopes and hills, whose strata are nearly perpendicular to thehorizon, are so much affected by larch and other trees, is, because themoisture in such situations is in motion, and often continues drippingthrough the fissures throughout the whole summer. The most desirablesituation for larch is where the roots will neither be drowned in stagnantwater in winter, nor parched by drought in summer; and where the soil isfree from any corrosive mineral or corrupting mouldiness. Larch , in suit-able soil, 60 years planted, and seasonably thinned, will have produced doublethe value of what almost any other timber would have done in the same timeand situation; and, from its general adaptation both for sea and land pur-poses, it will always command a ready sale.” (On Naval Timber, p. 85.)

Class II. Soils and Subsoils where Larch takes the Dry Rot . — The same ex-perienced and scientific author has enumerated the situations, soils, and subsoilsin which the larch, if planted, though it will grow freely, is subject to the rot, orto other diseases.

1. Situations (steep Slopes excepted) with cold TUI Subsoil , nearly imper-vious to Water. The larch succeeds worst when moorish dead sand, aloneor with an admixture of peat, occupies the surface of these retentivebottoms. Where the whole soil and subsoil are one uniform, retentive,firm clay, the larch will often reach considerable size before being attackedby the rot. When this heavy clay occupies a steep slope, the larch willsometimes succeed well, owing to the more equable supply of moisture, andthe water in the soil not stagnating, but gliding down the declivity. Ingeneral, soils the surface of which assumes the appearance of honeycomb intime of frost, owing to the great quantity of water imbibed by them, will notproduce large sound larch.

“ 2. Soft Sand Soil and Subsoil . Sand is still less adapted for growing larchthan clay, the plants being often destroyed by the summer’s drought beforethey attain sufficient size for any useful purpose : the rot also attacks themearlier on sand than on the clay. It appears that light sand, sloping considerablyon moist back-lying alpine situations, covered towards the south by steephills, will sometimes produce sound larch ; whereas, did the same sand occupya dry front or lowland situation, the larch would not succeed in it. Thesame moist back situation that conduces to produce sound larch in light drysoils, may probably tend to promote rot in the wet. The moisture and theless evaporation of altitude may also, in some degree, diminish the tendencyto rot in dry light sand, and increase it in wet clay. Larch will sometimessucceed well in sharp, dry, alluvial sand left by rivulets.

“ 3. Soils incumbent on brittle dry Trap, or broken slaty Sandstone . Althoughsoil the debris of trap be generally much better adapted for the productionot herbaceous vegetables than that of sandstone or freestone, yet larch does'lot seem to succeed much better on the former than on the latter. Thedeeper superior soils generally incumbent on the recent dark red sandstone,