some varieties of South American Guano. 133 



The next sample very much resembled the guano just de- 

 scribed, in its physical character ; some of the small lumps 

 were of a dirty white colour, and when broken showed no ap- 

 pearance of crystalline structure ; these were chiefly composed 

 of phosphate of lime; others showed brown silky crystals in 

 the interior, which, examined under the microscope, appeared 

 to be sulphate of soda and oxalate of ammonia. This, as well 

 as all the succeeding varieties of guano mentioned, was ob- 

 tained in January last ; this specimen was considered by the 

 importers to be of a very superior quality. The quantity 

 analysed was 500 grs. 



No. 2. 



O! 



Calculated Composition. 



fWater 21510 



Organic matter with 



combined water... 61*74 

 Sulphate of soda .... 37-90 

 Phosphate of soda... 35-82 

 Phosphate of lime... 12-56 

 Phosjjhate of ammo- 

 nia with some bi- 



phosphate'. 30-06 



Phosphate of potash 20-02 

 Muriate of ammonia 35-22 

 ^Oxalate of ammonia 100-38 

 Urate of ammonia... 25-12 

 Phospliate of ammo- 

 nia and magnesia . 4-04 

 Phosphate of soda?. 1-28 

 Phosph-dteoflime... 2-88 



Animal matter 6-38 



Oxalate of lime 107*26 



Phosphate of lime... 192-00 

 Phosphate of magne- 

 sia, trace of ammo- 

 nio-phosphate ... 19-84 



Humus 20-60 



Organic matter 11-40 



Water 42-42 



■Sand, &c 16-48 



Loss 1-50 



1000-00 



Ji ^ 



m 



1000-00 



Two other samples of a similar character, but much darker 

 in colour, were qualitatively examined : one, No. 3, contained 

 substances similar to No. 2, both soda and potash, some urate 

 of ammonia and very little sand and dirt; the other, No. 4, 

 was almost destitute of urate of ammonia or uric acid, the 

 faintest trace being discoverable by nitric acid and ammonia, 

 but in too small a proportion to enable me to isolate a particle 



