Composition of Guano. 49 



rytes and lime salts cannot be obtained well crystallized ; but 

 the other two are isomorphous, which is likewise the case with 

 the zinc and magnesia salts, both of which contain six atoms 

 of water, and crystallize in regular octahedrons. The copper 

 salt contains five atoms of water. The bromate of the prot- 

 oxide of manganese decomposes soon after its formation, bro- 

 mine being set free, and peroxide of manganese deposited. 

 Several of these bromates combine with ammonia in the moist 

 way, which was not known before. The copper and silver 

 salts take up each two equivalents, the zinc salt one equivalent 

 of ammonia, and, moreover, three atoms of water. Connected 

 with these experiments is the discovery of a double salt of the 

 iodide and bromide of mercury, which is formed direct, and 

 consists of an equal number of atoms of both salts. {Bericht 

 der Akademie zu Berlin, Dec. 1840.) 



Composition of Guano. 



The following analysis of this interesting and important 

 substance, made by M. Voelckel in the laboratory of Prof. 

 Wohler, confirms what Klaproth found*, viz. that the guano, 

 among its characteristic constituents, contains, besides un- 

 changed uric acid, a considerable quantity of two of its usual 

 products of decomposition, viz. oxalic acid and ammonia. 

 100 parts of moist guano contain: — 



Voelckel. Klaproth. 



Urate of ammonia 9*0 16*0 



Oxalate of ammonia 10*6 



Oxalate of lime 7*0 12*75 



Phosphate of ammonia 6*0 



Phosphate of ammonia and magnesia 2*6 



Sulphate of potash 5'5 



Sulphate of soda 3*8 common salt 0*5 



Chloride of ammonium 4*2 



Phosphate of lime 14-3 10*0 



Clay and sand 4'7 32*0 



Undetermined organic substances/ 



of which about 12 per cent, is so- i ?8*75 



luble in water. A small quantity 



of a soluble salt of iron. Water 



100-0 100-00 



{Ann. der Chem. und Pharm. vol. xxxviii. part 3.) 



* A memoir on Guano, by Laugier, will be found in Phil. Mag., First 

 Series, vol. xxiv. p. 126; from which it appears that Fourcroy and Vauque- 

 lin obtained similar results. Edit. 



Phil. Mag. S. 3. Vol. 19. No. 121. July 1841. E 



