180 W. J. Taylor on Rock Guano. 



I • Sulphtiric acid, 2-01 per cent. Oxygen ratio, 1'20 



Lirae, S'13 '' ** ^ " " 0'89 



Sesquloxjd of iron, 16-71 « " " " S'OO 



Alumina, 12-25 " " " " 5-70 



The specimens from whicii tlie material for tlie above analyses 



were selected, I received from Messrs. Eicbards and Miller, agents 



for the Philadelpliia Guano Company ; there is doubt as to their 



p exact locality ; in appearance they correspond exactly with that 



from Monk's Island, but the results of the analyses are very 

 different from those obtained from the specimens from this island 

 which I received from Dr, Luther. 



That alumina is present as a phosphatcj in the guano from 

 Monk's Island, I have proved, by treating 34023 grammes of 

 an average sample of the cargo of Schr. Trident from Monk's 

 Island, with pure caustic potash in a silver dish, which was found 

 to contain 1'32 per cent of alumina. 



Specimens were given me from Monk^s Island by Dr. Lnther, 



the characteristic appearance of which has already been de- 

 scribed. 



1'5915 grammes were treated in a silver dish with potash, but 

 not a trace of alumina could be detected ; the residue dissolved 

 in hydrochloric acid was found to contain lime, 39 '08 per cent. 



The guano rock from Monk's Island when finely powdered 

 and treated with distilled water, gave an acid reaction with lit- 



mus paper* 



(V.) 



1*7076 grammes (organic matter and water not determined). 



u 



it 





" 0'1003 gram. BaO, SOa gave sulphnric acid, 4*00 p*c 

 « 0-0780 " 2MgO,P05 " magnesia, 1-64 " 



" 1-1999 " CaO,C02 « lime, 39-34 " 



** 1-1461 " 2MgO,P05* ' phosphoric acid, 42-98 



Sulphuric acid, 4*00 per cent. Oxygen ratio, 2*39 

 Magnesia, 1'64 « " ** " 0-65 



Lime, 39-34 " " " " 11-10 



Phosphoric acid, 42'98 " « « " 24-09 



Tor the oxygen of the sulphuric acid, 2-39, there are required 

 0'88 of the oxygen of the lime ; and if to the remainder be 

 added the oxygen of the magnesia, we have lO'Oo, which is to 

 the oxygen of the phosphoric acid very nearly as 1 : 2. 



(VL) 



2'86'78 grammes treated with distilled water gave : 



" 2-7076 grams, residue, 94'41 p.c. 



" 0-1287 » BaO,S03 gave sulphuric acid, 1-49 '' 

 « 0-0655 " CaO,C02 « lime, P27 " 



« 0-0363 " 2MgO,P05 " phosphoric acid, 0-81 " 





a 



