Mr. Teschemacher's Examination of the African Guano. 395 



1 found to contain 4 per cent, of humic acid combined with am- 

 monia, with scarcely a trace of uric acid. The soluble parts of this 

 guano in water gave a very deep reddish-brown solution, very diffi- 

 cult to filter. Upon addition of acetic acid a brown flocculent preci- 

 pitate was produced, possessing all the properties of humic acid. The 

 solution was left of a light yellow colour, and now passed through 

 the filter with the greatest facility. From the great resemblance of 

 the dark brown solution to that of the liquor which runs from dung- 

 hills, and which is considered to contain the most valuable part of 

 the manure, I have no doubt that on account of the presence of 

 humate of ammonia in this guano it will act powerfully upon vege- 

 tation, in addition to its other ingredients, which are those usually 

 contained in other guano. 



I am, dear Sir, 



2 Park Terrace, Highbury, Yours truly, 



April 19, 1844. E. F. Teschemacher. 



P.S. Subjoined are the results of various analyses of guano. 



Dr. Ure. — Peruvian. 

 Azotized organic matter, including urate of ammonia, and 

 capable of affording 8 to 17 per cent, of ammonia by slow 



decomposition 50 



Water 11 



Phosphate of lime 25 



Ammonio-phosphate of magnesia, phosphate of ammonia, 



oxalate of ammonia, containing 4 to 9 per cent, ammonia 13 

 Siliceous matter 



100 

 Dr. Ure. — African. / 



Saline and organic matter, containing 10 per cent, ammonia 50 



Water 21-5 



Phosphate of lime and magnesia, also potash 26 



Silex 1 



Sulphate and muriate of potash 1'5 



100 

 Dr. J. Davy. — American and African. 



Soluble in water ; destructible by fire, or volatile, as 



oxalate of ammonia, diphosphate, muriate of am- Amer. African. 



monia and animal matter 41 '2 40*2 



Not destroyed by fire ; insoluble ; chiefly phosphate 



of lime and magnesia 29 28*2 



Not destroyed by fire ; soluble ; muriate of soda, and 



carbonate and sulphate of potash 2- 8 6 4 



Destructible by fire ; little soluble ; chiefly urate of 



ammonia 19 



Expelled by drying on steam-bath; chiefly water, 



and a little carbonate of ammonia 8 25"2 



100 100 

 No urea, or very little ; no oxalate of lime. 



