missionaries' use of poisons. John Young, an immigrant from the United States, reported two cases in particular that strained relations. In 1840, he was warned by William Gray of the mission melon patch, the larger of them poisoned. This was from Cayuse taking the produce, to safeguard the patch Gray stated that he " ... put a little poison ... in order that the Indians who will eat them might be a little sick ... " During the winter of 1846, Young was employed on the mission sawmill. Whitman gave him instructions to place poisoned meat in the area surrounding Waiilatpu to kill Northwestern wolves. Several Cayuse ate the deadly meat but survived. Tiloukaikt visited Waiilatpu after the people recovered, and said that if any of the sick Cayuse had died, he would have killed Young. Whitman reportedly laughed when told of the conversation, saying he had warned the Cayuse several times of the tainted meat. Measles was an epidemic around Sutter's Fort in 1846, when a party of primarily Walla Wallas were there. They carried the contagion to Waiilatpu as they ended the second Walla Walla expedition, and it claimed lives among their party. Shortly after the expedition reached home, the disease appeared among the general population around Walla Walla and quickly spread among the tribes of the middle Columbia River. By the 1940s, historians no longer considered the measles epidemic as a main cause of the murders at Waiilaptu. Robert Heizer said that "This measles epidemic, as an important contributing factor to the Whitman massacre, has been minimized by historians searching for the cause of the outrage." The Cayuse involved in the incident had previously lived at the Waiilatpu mission. Among the many new arrivals at Waiilatpu in 1847 was Joe Lewis, a mixed-race Iroquois and white "halfbreed". Bitter from discriminatory treatment in the East, Lewis attempted to spread discontent among the local Cayuse, hoping to create a situation in which he could ransack the Whitman Mission. He told the Cayuse that Whitman, who was attempting to treat them during a measles epidemic, was not trying to save them but to poison them. The Columbia Plateau tribes believed that the doctor, or shaman, could be killed in retribution if patients died. It is likely that the Cayuse held Whitman responsible for the numerous deaths and therefore felt justified to take his life. The Cayuse feared that he had