The following figures will give a limited but reliable survey of the growth of agriculture towards the end of the century. Before the year 1761 there were only between sixty and seventy sugar refineries on the island. By the end of the century there were four hundred and eighty. Before the year 1796 there were only eight or ten coffee plantations, so that the island barely produced enough coffee for its own consumption. By the end of the century there were three hundred and twenty-six "cafeyeres." At the same time the island had two thousand four hundred and thirty-nine vegas, or tobacco fields, and one thousand two hundred and twenty-three _colmenares_ or apiaries. The revenues of the island from 1793, when they amounted to over one million pesos, rose steadily until at the beginning of the century they were about three million pesos annually. The sugar plantations yielded great profits, but they also required big investments of money and labor. One of the most prominent sugar planters on the island, D. José Ignacio Echegoyen, calculated that to produce ten thousand arrobas of sugar, an expenditure of twelve thousand seven hundred and sixty-seven pesos was needed, besides a capital of sixty thousand. He was one of the foremost citizens that protested against the tax of one tenth on sugar. Work on the sugar plantations was the hardest imaginable; even the negro slaves could not stand it longer than ten years. Then their working capacity was completely exhausted and they were given their liberty. Though the importation of negro slaves essentially helped the development of agriculture and the industries connected with it, there still existed restrictions and regulations which acted as a continual check upon the growth of the population, and had a paralyzing effect upon the intellectual development of the colonists. A favorable solution of these important questions offered great obstacles. Although the principles on which Spain founded her restrictive system had been relaxed, there existed a great number of interests that had been created through this system and were unwilling to give up their privileges. Derogation of these restrictions would have meant loss and injury to some peninsular subjects that had grown rich and powerful through them.