48 



always be stated where it is well ' defined ; but in hilly 

 ground a single block often faces several points of the 

 compass. The slope may be stated in a single word. A 

 slope is said to be gentle when the inclination is not greater 

 than about 1 in 6 ; it is steep when more tlian 1 in 6 but not 

 greater than 2 in 3 ; it is very steep when more than 2 in 3, 

 and becomes precipitous when it reaches 1 in 1. 



(iii) The soil. — The more important facts with regard to 

 the soil may be expressed in a few words descriptive of its 

 surface, its composition, its physical state, its depth and iis 

 fertility. The fertility or productive value of the soil, as 

 regards the species which has to be considered, may gener- 

 ally be summed up by such terms as "good" or "very 

 good ", " bad " or "very bad", as the case may be. With 

 regard to its surface, the soil may be quita bare and hard, 

 or covered with a layer of leaves, or with vegetable 

 mould apt for the reception of seed. Or it may be car- 

 peted with moss or grass or over-grown with bushes. The 

 physical character of the soil — its looseness and the size of 

 the particles forming it — are, however, of greater import- 

 ance as regards forest vegetation than the chemical com- 

 position. The soil may be formed of stiff clay, loose sand or 

 agglomerations of stones and boulders ; while its hygrosco- 

 picity may vary from marshy to dry. But of all the, pro- 

 perties of the soil depth is perhaps the most important and 

 is that which is most likely to vary. Depth of soil is at 

 onco manifested by the appearance of the trees. If shallow, 

 the boles are generally short and the crowns low ; while the 

 contrary is the case on soils of from 12 to 20 inches and over 

 in depth. 



The nature of the underlying rook and sub-soil is often 

 of great importance. 



Very little is known as yet of the inflaeaoe exerted by different soil on the growth 

 and producr.ion of the various species of Indian forest trees ; it is not often, therefore, 

 that a description of the chemical characters of the soil can be of much service. Bnt 

 when a detailed plan is prepared, the nature of the soil in each coaipartment should 

 be noted, and tl>e relative proportions of clay, sand and lime should be roughly 

 ascertained. By noting such paitiuulars many valuable indications can be deduced, 

 especially when a complete record of the production has been kept for a number of 

 years. Small portions of the soil it is wished to examine should be taken from 

 several different spots in the nursery or compartment under observation, and 

 should be mixeJ together. A small portion should then be reduced to powder in a 

 mortar and the veg -table detritus removed by heating. The residue should then be 

 treated with dilute hydrochloric acid, and the irsoliible portion, consisting of clay and 

 sand, separated by filtration from the soluble portion (caloium, iron, etc.). The clay 

 can then be separated from the heavier sand by deoanting several times with the aid 

 of a syphon. And the relative proporti(>n of each determined by weighing. If, when 

 the hydrochloric acid is first added, there is a brisk effervescence, the soil is calcareous. 



