The Mayans appear to have been, at any rate in later times, great traders. Cortes encountered them trading round the coasts of the West Indian Islands, and they certainly trafficked with the tribes of Mexico and Honduras. Trade was carried on principally by means of barter. Their exports were salt, cotton cloth, dried fish, and resins; their imports, the cocoa bean, stone beads, nephrite stone from the highlands of Mexico, mineral paints and obsidian, of which they made knives or lance-heads. From Guatemala, too, they got jade. There may have been also a traffic in slaves. There was no standard coinage, for metals were almost unknown; but more as counters than as money were used the cocoa bean, tiny bells, and rattles of copper and stone beads. Sales do not appear to have been evidenced by writings. One chronicler states that a bargain, especially in the sale of slaves, was clinched by the two contracting parties drinking together before two witnesses. The Mayans had many industries, chief among them being those of the potters and the carpenters. The men who carved the wooden, or moulded the pottery idols, lived under severe rules, passing a hermit's life in a hut on the outskirts of the city, dividing their time between work and fasting. To them once a day food was taken by a member of their family, but it was a strictly vegetable diet, as all flesh was forbidden them. A continuous vigil was enjoined upon them until each special task was complete. The Mayan doctors and medicine men treated their patients with herbs and enchantments. They were in much request at confinements and in cases of snake-bite. They were also employed to divine the future and to pronounce a benediction on new houses. As we have said, land was held to be common property. There was no strictly proprietary right. Its products belonged in each case to the first occupier; but occupation itself gave but a precarious right which lasted only for the full term of one agricultural season. After harvest the land reverted to public use. This community of land was traditional among the Mayans, and was doubtless largely due to the character of the soil, which did not permit of its being cultivated more than two years running. After two harvests it was exhausted, and had to be allowed to lie fallow. The lands of the caciques and nobles were cultivated by slaves; but the common people helped each other in their sowings and harvestings.