1848.] 



The Neilgherry Motmiaifis. 



5 



This advantageous contrariety may, perhaps, be accounted for by 

 referring the formation of so much rich soil to the existence of the 

 numerous dykes of rock, whose decomposition is more favourable to 

 its production, especially those of trap and hornblende, the decomposed 

 particles of which, mixing with the quartzose and clayey products of 

 the granite, result in the formation of a soil peculiarly adapted for 

 cultivation. 



The great mass of the Hills also has evidently been under grass, 

 and undisturbed by the plough or the mamotie for ages, and as the 

 frosts which occur at the close and beginning of the year in most parts, 

 kill the grass down to the roots, all this decomposed vegetable matter, 

 washed in by the succeeding rains and mixing with the subsoil, con- 

 tinues, and has continued, season after season, to increase its richness, 

 and cause it to penetrate further and further into the poorer subsoil, 

 until the extraordinary depth of rich black mould, which is often 

 observed in the cuttings of a new road, is produced. 



The finest patches of land are naturally found on the lower slopes 

 or second steppes, in situations where the conformation of the country 

 has favored the accumulation of soil washed from the hills above, and 

 especially where forests have aided to retain that soil from further 

 denudation by their roots, and have for ages nourished it by their 

 leaves. The chief agricultural tribe on the Hills, the Burghers, seem 

 well aware of this, and the consequence is that in all parts where 

 they cultivate, the face of the country is entirely clear of wood. 



Want of Lime ^^^^ chief defect of the soil of this district is the 



absence of lime, but a very minute quantity of 

 which enters into the composition of the greater part of that under 

 general cultivation at the present time, and as it is too costly an ar- 

 ticle to be brought up from the plains to be applied as a dressing to 

 the land, considerable deterioration must be going on in its produc- 

 tive capacity. I have remarked that the finest fields are those which 

 are situated near any considerable mass of hornblende rock, and hence 

 it is to be inferred that the superiority of the soil is due to the lime 

 which it receives from its decomposition. Specimens of this horn- 

 blende reduced to powder and digested in dilute nitric acid, give a 

 copious precipitate with oxalate of ammonia, showing upon estimate 

 (for I had not the means of collecting and weighing the precipitate), 

 a proportion of at least 8 to 9 per cent, of lime entering into the com- 

 position of the rock. 



