No. iV.] ON EXPERIMENTS WITH GUANO. SS 



an enterprising merchant in Liverpool, and it has been deservedly recommend- 

 ed to the attention of British agriculturists. It has already been tried upon va- 

 rious crops, both of lny and corn, upon turnips also, and upon hops, and there 

 can be no doubt whatever that in our climate, as well as in that of Peru, it is 

 fitted to promote vegetation to a very reaiarkable degree. 



This brown guano varies much in quality, accordmg probably to the degree 

 of exposure to the air to which it has been subjected, or to its position in the de- 

 posit from which it has been dug. Two different portions, taken at random 

 from the same box, gave me the following very different results : — 

 1°. — Water, salts of ammonia, and organic matter, expelled 



by a red heat, 235 per ct. 



Sulphate of soda, ; 1-8 " 



Common salt, with a little phosphate of soda, . . 303 " 

 Phosphate of lime, with a little phosphate of magnesia 



and carbonate of lime, 44-4 " 



100* 



2°.— Ammonia = 70 ] 



Uric acid, =08 1 59.3 . 



Water, carbonic and oxalic acids, &.c., expelled j ^ 



by a red heat, =51-5 j 



Common salt, with a little sulphate & phosphate of soda, 11-4 " 

 Phosphate of lime, &c 293 " 



100 



According to M. Winterfeldt, this brown guano is sold at the ports near 

 which it is obtained at about 3s. a cwt. It might, therefore, if this be correct, 

 oe importeci into the country, and sold at less than lOs. per cwt. The price at 

 present asked, however, is 25s. per cwt., a cost at which it is doubtful if the 

 English agriculturist can afford to use it. 



In any case it seems improbable that the guano can continue to be imported 

 into this country for any length of time. It is absolutely necessary to the cul- 

 tivation of the land in Peru,— and it is also diminishing in quantity, — the first 

 settled government, therefore, which is formed in that country, must prohibit 

 the further exportation of a substance so important to the national interests. It 

 is a matter not unworthy of the attention of chemists, therefore, to consider 

 whether a mixture similar to the guano, and of equal efficacy, cannot be form- 

 ed by art — not only at a cost so reasonable as at once to make the British 

 farmer independent of the importer, — hut also in such abundance as at the same 

 time to place so valuable a manure within the reach of all. 



The following mixture contains the several ingredients found in guano in 

 nearly the average proportions ; and I believe it is likely to be at least as effica- 

 cious as the natural guano, for all the crops to which the latter has hitherto been 

 applied in this country: — 



315 lbs, [7 bushels] of bone dust at 2s. 9d. per bushel 

 100 lbs. of sulphate of ammonia,t containing 35 lbs. of ammo- 

 nia at 20s. a cwt 



5 lbs. of pearl-ash . . .... 



100 lbs. of common salt . 



1 1 lbs. of dry sulphate of soda .... 



531 lbs. of artificial guano cost . .... 



* The first contained also 8 per cent, and the second IJ per cent, of sand, which has been 

 left out of the true composition of the guano considered as free from sand. 



t Sulphate of ammonia is now manufactured largely at Glasgow, and may be had for less 

 than 208. a cwt. 



