5,918 | 7,814
Dutch West Indies | | |
(Curacao, Aruba) | 14,763 | 8,851 | 6,648
British West Indies | | |
(Sombrero, &c.) | 3,970 | 1,960 | 2,473
Spain and Portugal | - | 320 | 971
Belgium | 82,096 | 70,723 | 65,079
Holland | 2,428 | 3,434 | 6,627
France | 35,659 | 18,325 | 18,239
Australia | - | - | -
Germany | - | - | -
Hayti (San Domingo) | 992 | 1,639 | 2,965
Brazil | - | - | -
Venezuela and Guiana | - | 540 | -
Norway | 4,151 | 1,495 | 305
Other countries | 1,070 | 1,483 | 1,594
| | |
*Florida phosphate. | - | 35,203 | 66,327
Carolina phosphate. | - | 96,881 | 135,138
-----------------------+---------+----------+----------

CHAPTER XIII.

SUPERPHOSPHATES.

As was mentioned in the chapter on Bones, Liebig in the year 1840
discovered that the effect of adding oil of vitriol, or sulphuric acid,
to bones was to render the phosphate they contain soluble. This
discovery marked an epoch in the history of artificial manures, and laid
the foundation of the now enormous manufacture of superphosphate. In
1862 the juries of the London International Exhibition published an
elaborate report containing an interesting article on the manure trade
of Great Britain, in which it was stated that the annual quantity of
superphosphate then made amounted to from 150,000 to 200,000 tons. Now
it may be placed not far short of a million tons. Probably that made in
the United States is considerably more. In the first instance,
superphosphate was manufactured by Sir John Lawes from spent bone-char.
This was superseded by coprolites and Estremadura phosphorite, Suffolk
coprolites being for many years the chief material employed. This in
turn was succeeded by the richer Cambridge coprolites, but of late years
coprolites have practically ceased to be a source of superphosphate, the
other mineral phosphates mentioned in the previous chapter--such as the
South Carolina, Belgian, Somme, &c., phosphates--taking their place.

_Manufacture of Superphosphate._

The manufacture of superphosphate is of too technical a nature to permit
of discussion in