Miscellaneous Intelligence, 



299 



5. Monies Island or Colombian Guano; by Dr. A. S. Piggot, (Proc, 

 Amer. Phil. Soc., Philad. vi, 189). — In the spring of 1855, there was 

 brought into the port of Baltimore a hard, rocky substance, which was 

 offered for sale under the name of Colombian Guano. At first, there was 

 a great effort made to involve in mystery the whole history of the article, 

 its locality being carefully kept secret. Gradually, however, it became 

 known that it was found on Los Monges, a collection of keys at the en- 

 trance of the Gulf of Maracaibo. It has also been found on El Ronca- 

 dor, off the Musquito coast, on Aves and various other keys of the Carib- 

 bean Sea. On Los Monges, it forms, as the captains who procured it 

 say, a thin polished crust over the entire surface. Below this crust lies 

 the common Mexican guano. In some instances, however, this same 

 smooth incrustation covers thinly the jutting points of primitive and met- 

 amorphic rocks. I have before me a splinter of rock of this kind, crested 

 with an inch-thick deposit of this guano ; and I have seen many in which 

 the white crust formed a thin lamina over the surface. Many such were 

 brought in, in the first cargo, which will account for the large amount of 

 sand in the subjoined analysis. Only the ground guano was thus sent to 

 me, so that the analysis represents the commercial article, not a selected 

 specimen. The actual guano contains only about 0*5 per cent of siliceous 

 matter. 



The unusual quantity of phosphoric acid, contained in this substance, 

 attracted attention, and many analyses were made of the new guano. 

 The habit of calculating the phosphates in these Mexican guanos, as bone 

 earth, or tribasic phosphate of lime, led some chemists into grievous er- 

 rors. The new material was, in one breath, called a superphosphate of 

 lime, and in another, said to contain from seven to eleven per cent of 

 free phosphoric acid. In common with other chemists of Baltimore, on 

 the first importation of this guano, I made an analysis of it, and found it 

 to contain a large proportion of phosphates, but expressed no opinion as 

 to their composition. At last, however, hearing so much said about the 

 soluble phosphoric acid in this substance, I examined it more carefully, 

 and found but little of this acid soluble in water, and none of it free. I 

 obtained the following results : 



Phosphoric acid, 41*62 



Sulphuric acid, . - 3-65 



Chlorine, - - * - - 0"5 



Lime, - - - - - - 33-83 



Magnesia, - 3*27 



Iron, - trace. 

 Fluorine, ------ trace. 



Sand (consisting chiefly of primitive rocks in powder,) 5*34 



Water (hygrometric,) - - - - 2*15 



Organic matter, salts of ammonia (containing 0*23 of am- 

 monia) and combined water, - 8*62 

 Loss, in which are the alkalies (not estimated,) - - 1*47 



100-00 



The proportions of the phosphates vary in different samples. Thus, in 

 one specimen, recently examined, there was a very small proportion of 

 magnesia and 4*23 per cent of phosphate of iron. 



