218             JOURNAL OF PROCEEDINGS          [Feb. 2,

40 per cent, of phosphoric acid in combination with oxide of
iron and alumina.

Quantity and quality of Columbian Guano inspected from
March 1st, 1856, 1,023 tons and 935 lbs. letter A.

2. WHITE MEXICAN GUANO.

This article is now imported from the island of Sombrero,
in lumps, and is ground for market. It contains a large per
centage of phosphoric acid in combination with lime and a
small per centage of iron and alumina.

Inspected since March 1st, 1856, 1,405 tons and 483 lbs.
marked A.

3. AMERICAN GUANO.

This is the ordinary brown Mexican Guano, and is very
different in quality, it being imported of all grades, varying
from 15 to 60 per cent, of Phosphate of lime. The deposits
of this Guano unlike Peruvian, being exposed to the alternate
effects of rain and sun, undergo decomposition by which
ammonia is formed, and from its volatile nature passes off in
the atmosphere, while the soluble salts are dissolved and
washed out by the rain, leaving the permanent salts consist-
ing of Phosphate of lime, chiefly in the deposite in increased
proportion to the loss of the whole occasioned by vaporization
and solution.

The principal variation in quality of this variety is owing
to the admixture of coral sand with which the islands and
keys, abound.

Inspected since 1st, March of Mexican Guano, to wit:

Quality	A. A. |	A.	B.
Quantity	11,114 tons 1731 lbs.	314 tons 1435 lbs. |	none.
Quality	C. |	D.
Quantity	648 tons 1328 lbs.	94 tons 515 lbs.

4. EL ROQUE GUANO.

This Guano has been recently imported from "El Roque"
and resembles in appearance Colombian. By analysis it is
found to contain a large per cent, of Phosphoric Acid, while
it differs in composition from Colombian, having for its base
iron and alumina, while the base of the former is lime. Ex-
perience must determine its value as a fertilizer. Quantity
and quality inspected, 361 tons and 15 lbs. marked A.

WEIGHING, &c.

Since the 1st, March 1856, M. Robert Massicot, a practical
weigher, has weighed under the direction of the undersigned