160 Dr. Heifer's Fourth Report [No. 98. 



face is decomposed, and throughout covered with lofty vegeta- 

 tion; a bare rock is one of the greatest rarities on the main 

 land. The felspar decomposes exceedingly quick in tropical 

 humid countries, and is found, contrary to the theory of 

 celebrated chemists, one of the most fertilizing substances 

 within the tropics ; the reason is probably that the caustic of 

 potassa or soda, which forms part of the elements of felspar, 

 is neutralized by the abundance of humic acid produced by 

 the immense quantity of decaying vegetable matter. 



Hence we see that the valleys between the granitic ridges 

 of the country into which all the decomposed particles are 

 uninterruptedly swept from the sides of the mountains, toge- 

 ther with the numerous decayed vegetable substances, belong 

 to the richest soils of this country. Just this part of the 

 country, chiefly inland, is uninhabited, or only employed by 

 isolated Kareans. Not an inconsiderable portion of the surface 

 of the provinces belong to the transition formations. They are 

 much more abundant in the northern and middle, than in the 

 southern parts. These are to be divided into the schistous 

 and calcareous surfaces. 



A great part of the country to the south of Maulmain and to 

 the south of Ye, towards Tavoy, present argillaceous transition 

 schist. This is that part of the country which is the most sterile 

 of all ; a more stunted vegetation is immediately observed, and 

 great part of this tract instead of presenting lofty forests, is 

 covered with bamboo. The chief reason of this sterility may 

 be accounted for, by the deficient and but slow decomposition 

 of the schists, and by the absence of sandy particles, and by 

 the great absorption of water and moisture. 



The province of Amherst possesses remarkable isolated rocks, 

 or ridges of some extent, composed of mountain limestone. 



The plains at the base of these abrupt mountains are remark- 

 ably fertile. 



The mountains themselves, however, rising sometimes per- 

 pendicularly, full of chasms, without any level ground, will be 

 found in every respect unavailable for cultivation. 



Secondary formations, and amongst those the secondary sand- 

 stones (Gres bigarre) with puddingstones, cover the surface. 



