189 



Senate Reports, 2d Session of 33d Congress, 1854-5, 1 vol. 



Reports of House Committees ,, ,, 1 vol. 



House, Miscellaneous, „ ?? 1 vol. 



List of Private Claims, „ „ 2 vols. 



From the Department of State, Washington. 



Report of the Commissioner of Patents, for the year 1851. Part 2. 

 Agriculture. Washington, 1852. 8vo. 



Messacre from the President of the United States to the two Houses of 

 Congress at the commencement of the First Session of the 34th 

 Congress; — with accompanying Documents. Parts I. II. (2 vols.) 

 Washington, 1855. 8vo.— From the Hon. J. R. Tyson. 



Monthly Notices of the Royal Astronomical Society. Vol. XVI. No. 

 5. March 14, 1856. London. 8vo. — From the Society. 



The African Repository. Vol. XXXII. No. 4. April, 1856. Wash- 

 ington. 8vo. — Froin the Am. Colonization Society. 



The Astronomical Journal. Vol. IV. No. 20. April 26, 1856. Cam- 

 bridge. 4to. — From the Editor. 



The Medical News and Library. Vol. XIV. No. 161. May, 1856. 

 Philadelphia. 8vo. — From Blanchard i^ Lea. 



Mr. Trego laid upon the table a specimen of " Colombian 

 Guano/^ from Monks' Islands, in the Caribbean Sea, near the 

 entrance to the Gulf of Venezuela or Maracaibo. The speci- 

 men was presented by Dr. A. S. Piggot, of Baltimore, from 

 whom the following communication has since been received. 



In the spring of 1855, there was brought into the port of Bahimore 

 a hard, rocky substance, which was offered for sale under the name 

 of Colombian Guano. At first, there was a great effort made to in- 

 volve 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 entrance of the Gulf 

 of Maracaibo. It has also been found on El Roncador, off the Mos- 

 quito coast, on Aves and various other keys of the Caribbean sea. On 

 Los Monges, it forms, as the captains who procured it say, a thin po- 

 lished crust over the entire surface. Below this crust lies the common 

 Mexican guano. In some instances, however, this same smooth incrust- 

 ation covers thinly the jutting points of primitive and metamorphic 

 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 



