hundred million dollars yearly.

It was soon found out that the nitrate in its raw state contained
properties that were injurious to plants and that these should be first
eliminated. Forthwith reduction works were established to extract the
deleterious substances. These substances were mainly iodine and bromine,
two chemical elements that are of greater value than the nitrates
themselves. Within a few years railroads were built to transport the
nitrates from the beds to the various ports where the reduction
factories were erected.

Many men who had large interests in the nitrate beds became immensely
wealthy in a short time. The great value of the deposits caused towns
and cities to spring up along the coast in the most inhospitable places,
to some of which water was piped a distance of more than two hundred
miles and at the cost of many millions of dollars.

The principal nitrate beds are in a shallow valley, four or five
thousand feet above sea level, lying between a long range of hills and
the base of the Andes. Just how these mineral deposits were formed it is
difficult to explain, the most plausible theory being that this desert
was once the bottom of an inland sea having vast quantities of seaweed
covered with sand. In the gradual decay of this substance the nitrate of
soda, or "Chile saltpetre," was formed.

To obtain the nitrates it is necessary first to remove the top layer of
sand and then a layer of clay. Underneath this is found a layer of soft,
whitish material called "nitrate." The crude nitrate is sent to the
nitrate ports to be crushed and boiled in sea-water. After boiling, the
solution is drawn off into shallow vessels and exposed to the heat of
the sun to evaporate.

When nearly all has been evaporated and the remaining liquid drawn off,
the bottom and sides of the vessels are found to be covered with
sparkling white crystals. This is the saltpetre of commerce, the highest
grade of which is used in the manufacture of gunpowder, the second grade
for chemical purposes, and the third grade, the great bulk, for
fertilizing the exhausted soils of Europe.

The liquid drawn off is crystallized by chemical treatment and further
evaporation, and from it is obtained iodine, an ounce of which is worth
as much as one hundred pounds of saltpetre. From eighty to one hundred
million dollars' worth of these nitrates are dug out and sold each year.
Great Britain takes about one-third of the entire product and