The investment of large amounts of foreign capital in the exploitation of the deposits of nitrate of soda had made that province economically very valuable, and the export tax levied on the product was the chief source of the national revenue.

These were all potent reasons why Chile wanted to keep its hold on Tacna and Arica.

Besides, possession was nine points in the law! On the other hand, the original plan of having the question decided by a vote of the inhabitants of the provinces concerned was not carried into effect, partly because both claimants cherished a conviction that whichever lost the election would deny its validity, and partly because they could not agree upon the precise method of holding it.

Chile suggested that the international commission which was selected to take charge of the plebiscite, and which was composed of a Chilean, a Peruvian, and a neutral, should be presided over by the Chilean member as representative of the country actually in possession, whereas Peru insisted that the neutral should act as chairman.

Chile proposed also that Chileans, Peruvians, and foreigners resident in the area six months before the date of the elections should vote, provided that they had the right to do so under the terms of the constitutions of both states.
Peru, on its part, objected to the length of residence, and wished to limit carefully the number of Chilean voters, to exclude foreigners altogether from the election, and to disregard qualifications for the suffrage which required an ability to read and write.