The wide publicity given in recent years to the production of cancer in human beings by contact with lubricating oils has caused considerable concern as to the possible dangers of using the heavy oils for therapeutic purposes. This apprehension is of course the result of complete lack of knowledge of the exact conditions under which such oil cancer appeared. Therefore, while several investigations have been made of the carcinogenic possibilities of specially purified oils, a study on a large scale of some widely used therapeutic products was considered advisable.
The facts about oil cancer have been only recently discovered. Southam and Wilson1 in 1922 called attention to the fact that cancer of the scrotum was unduly frequent in mule-spinners whose clothes are saturated with lubricating oil from the machinery which they attend. Scott in 19232 published an extensive paper on the cancer of workers in the Scottish shale