What would happen if a monkey smoked marijuana? Rhesus monkeys have been falling victim to human curiosity on that score since the 1890s when one in Calcutta gave his life for the Indian Hemp Drugs Commission. Two scientists there tried such an experiment again in the thirties, and a brain researcher in New Orleans did it his own way in the seventies. (We will describe his work later.)
One Doctor Cunningham reported to the commission how he made a rhesus inhale ganja in a special chamber 181 times in eight months, 1893-94. Resisting the treatment in the earlier part of the experiment and trying to plug the tube carrying in smoke, the monkey evidently became addicted later on; he did not want to leave the chamber without his full dose and became uneasy on smokeless days. Symptoms commonly included unsteadiness, drowsiness, and “loss of will-power accompanied by optical delusions” that persisted long beyond other signs of intoxication. Sometimes violent convulsions seized him and he lost consciousness. In a postmortem, the “cerebro-spinal nervous centres” appeared healthy.
Chopra and Chopra later subjected two monkeys to “frequent inhalations of ganja smoke” (half a gram to two grams of marijuana) for three months to test addiction. At first their monkeys too had an aversion to the contamination and it was hard to get them to inhale the fumes. They became restless and often tried to close the hole through which the smoke entered their chamber.
After three weeks of daily smoke, the animals began to show some liking for it. After four weeks the monkeys became quiet and often reacted to the smoke by falling asleep or moving and sitting with difficulty, their eyes congested. Relatively small doses brought a reeling gait, restlessness, and watery eyes. “The animals looked confused and this condition continued for a considerable time after all other signs of active intoxication had disappeared.” (Within six months they died of dysentery.)