In addition, the legislature passed the Negro Act of 1740 to tighten controls: it required a ratio of one white to ten blacks on any plantation. It prohibited slaves from growing their own food, assembling in groups, earning money, or learning to read. In the uncertain world of the colony, several of the law's provisions were based on the assumption that whites could effectively judge black character; for instance, whites were empowered to examine blacks who were traveling outside a plantation without passes, and to take action.