Panama to Patagonia

by Charles M. Pepper

The quality of the saltpetre thus crystallized is 95 per cent of nitrate of soda, and it is known by the name of ordinary or current saltpetre. Refined saltpetre of the grade of 96 per cent is also obtained by submitting the warm solutions to a light and short decantation, by which there is left a part of the salt and the impurities. The refined product is passed immediately to the crystallizing vats. For this process powerful machinery is used which can refine 1,000,000 pounds of saltpetre daily. The residue of the nitrate of soda is known by the name of ripio. Its percentage of saltpetre is estimated below 15.

The saltpetre zone is served with railways. These leave the various ports and ascend to a height of 4,000 feet above sea-level, with the exception of those of Caleta Buena and Junin, which stretch from the summits of the neighboring Cordillera to the sea and are united with the ports by means of automotors. The automotor plano of Junin has a vertical height of 2,145 feet, and those of Caleta Buena 2,430 feet.

The Granja or Challorcollo road traverses the pampas of Tamlugal, and reaches the foot of the hill of Challorcollo. From this point there is a hanging railway, which reaches the mines in the summit of the hill at a height of 4,600 feet and is two miles long.

An important factor in the production of nitrates is coal, which is used in large quantities, the consumption being not less than 400,000 tons annually. The prices fluctuate from 22 to 28 shillings per ton. Generally English coal or that from Australia is used. Chilean coal is not employed to any extent. The home production is hardly sufficient for the needs of the railroads and the industries in the southern part of the country. Besides, the ships which carry the nitrates to foreign ports return with coal as the cargo. The freight rates to Europe for the nitrates vary from 20 to 30 shillings per ton.

In all the deposits iodine is found formed of salts with the base of soda. The salts of iodine dissolve along with the nitrate of soda, and later are extracted from the mother waters which have remained after the crystallization of the saltpetre. The process is simple and cheap, and the iodine is obtained in the metallic state and perfectly pure, in which condition it is a commercial commodity.

The small consumption of iodine in the industry has caused the producers of the entire world to form a combination to limit the production and fix its relation to consumption. The agreement obliges all the saltpetre establishments of each country to withdraw only a very small part of the iodine which their properties contain. At some future period the refuse of the saltpetre will be worked to extract the iodine.

The annual production of iodine is approximately 4,200 Spanish quintals. The price of the substance is about 5½ pence per troy ounce. The total export tax varies from $150,000 to $100,000.

To the east of the ports of Punta de Lobos and of Hurmillos is a great salt field extending over an area of 32,000 hectares, or 80,000 acres. It is covered with common salt, or chloride of sodium. The salt is perfectly pure and crystallized. The analyses have given 99.99 per cent of chloride of sodium. The thickness of this salt layer is not known. The deepest wells have reached 82 feet. In a recent year 220,000 quintals were exported to the interior of the country. The good quality of this salt allows it to be used in every class of industry and also for domestic purposes. Besides the great salt bed named, there are various others, but these are not so important.

The number of laborers employed in the nitrate industry varies from 20,000 to 25,000 according to the activity of the season. Production in some years has been curtailed through the scarcity of labor or through strikes and similar causes.

The principal application of saltpetre is in agriculture, it being employed as manure for land worn out by many years of continuous cultivation. Some crops give 25 per cent to 30 per cent more than those which are raised without fertilizing the ground with nitrates. In special cases the returns have been much larger, and it is on this account that this fertilizer has obtained so considerable an increase in all markets.