39^ 



These results show that although these, guanos are comparatively 

 rich in phosphoric acid — of which a fairly large proportion is so- 

 luble in ammonium citrate solution and is therefore in a form in 

 which it could be utilised by plants — they are deficient in the very 

 important constituents, potash and nitrogen. The guano of com- 

 merce obtained in Chili and Peru contains as a rule from 7 to 12 

 per cent, of " total nitrogen, " 1 1 to 14 per cent, of phosphoric acid, 

 3 to 6 per cent, of potash, and 1 1 to 15 per cent, of lime (present 

 as calcium phosphate). Comparing these figures with those ob- 

 tained in the course of this examination of the bat guanos from the 

 Federated Malay States, it will be seen that although the latter are 

 fairly rich, particularly as regards samples A and 3, in phosphoric 

 acid, yet this deficiency in the other important constituents of 

 manures — viz., potash and nitrogen — would prevent their being 

 used as general manures in the same way as South Amerjcan 

 guanos, and they could only be satisfactorily employed in conjunc- 

 tion with other materials rich in potash and nitrogen. They re- 

 semble to some extent the so-called phosphate guanos, now 

 imported in considerable quantities into this country, which, how- 

 ever, contain as a rule at least 30 per cent, of phosphoric acid in 

 the form of calcium phosphate. 



The best of the four bat guanos from the Federated Malay States 

 is sample A, which contains 2 per cent, of potash, 2.47 per cent, 

 of nitrogen in the form of ammonium nitrate, and 17.52 per cent, 

 of phosphoric acid in the form of ferric, aluminium and calcium 

 phosphates. An unusual constituent of this sample is 28 per cent, 

 of calcium sulphate. The phosphoric acid content of this guano 

 would be worth about £2 16s. per ton in this country, and it is 

 unlikely that the small amounts of " nitrogen " and potash present 

 would enhance its commercial value. This price is undoubtedly 

 too low to permit of profitable export, and it would probably prove 

 more remunerative to employ the guano locally. In this connection 

 it may be mentioned that the calcium sulphate present in the 

 material, though of no direct value as a manure, might be utilised 

 indirectly by using the guano in conjunction with dung or any 

 similar material which would undergo ammoniacal fermentation, as 

 the ammonia and carbon dioxide generated by the fermentation 

 would convert the calcium sulphate into ammonium sulphate and 

 calcium carbonate, thus affording at once two important constitu- 

 ents of manures, viz., " nitrogen " and lime, in forms in which they 

 can be readily assimilated by plants. Calcium sulphate is frequent- 

 ly used in this way as an indirect manurial agent, and is regularly 

 mined in the United Kingdom for this purpose. 



The other guanos, Nos. 1, 2 and 3, would be of comparatively 

 little commercial value in this country, but there is no reason why 

 they should not be utilised in the Federated Malay States as phos- 

 phatic manures. When used in this way it must be understood 

 that the soils to which they are applied may also require applications 

 of other manures containing nitrogen and potash. It is noticeable 

 that in samples Nos. 1, 2 and 3, taken at the surface, and six inches 



