130 



Scientific Intelligence. 



The original crystals contained the following constituents in 100 



parts as : 



Crystallized ammonia-phosphate of soda, 



Organic matters, (urates, humates, &c.) 



Phosphate of potash, . 



Chlorid of sodium, .... 



Carbonate of lime, . 



Carbonate of magnesia, 



Phosphate of lime, . 



Silica, sand, &c. . . • 



Water and loss, . 



91-660 

 1-956 



traces. 



0-520 



0-280 



traces. 



2-100 



2151 



1-332 



i 



100-000 



With regard to the manner of the formation of this salt, it is ex- 

 tremely difficult to comprehend how such a compound as the ammonia- 

 phosphate of soda could be produced by the decomposition of a sub- 

 stance so remarkably deficient in the alkalies as guano. For unless we 

 conceive that there was in this case a peculiar and special source of the 

 soda, we must of necessity admit that it was obtained from the decom- 

 position of the chlorid of sodium of the sea-water by the phosphate of 

 ammonia of the guano — the resulting chlorid of ammonium being 

 either volatilized at the high temperature of those climates, or, from its 

 extreme solubility, dissolved out by the rain-water and carried into the 

 sea or the lower strata of the guano deposits. We well know that 

 chlorid of sodium is capable of being decomposed by phosphate of 

 ammonia at a high temperature. May not this decomposition, there- 

 fore, also take place when the salts are in solution ? I think it very 

 probable. 



This being the first instance in which the ammonia-phosphate of 

 soda has been met with as a natural production, 1 propose to class it 

 amongst our minerals under the name of " Stercorite."* 1 should 

 have preferred to have given it that of Guanite, as being more indica- 

 tive of its origin, but this has been already applied by Mr. Tesehemacher 



to the ammonio-magnesian phosphate, another product of the decom- 

 position of guano. 



I have also examined another salt which was met with in the same 

 cargo of guano as the preceding, to which it bore a very close resem- 

 blance, both in physical and chemical properties. Like it, it was fran- 

 gible, crystalline, and readily soluble in water, and gave off arnmoni- 

 acal fumes when heated to redness or when treated with caustic potash ; 

 it also gave a yellow precipitate with nitrate of silver; but it differed 

 from it in efflorescing upon exposure to the air, and in not giving a pre- 

 cipitate with antimoniate of potash. 



The primary form of the crystal, as nearly as could be determined 

 from the few imperfect specimens in my possession, was an oblique 

 rhomboidal prism, with a dihedral summit. Upon redissolving these in 

 water and recrystallizing by spontaneous evaporation, long acicular 

 crystals were obtained, which, when dried between pieces of bibulous 

 paper and subjected to analysis, afforded the following results: 



* From the Latin " Stercoro" to dung or manure land. 



