Schamberg* has recently published a most complete paper on the prevalence of cancer in tar workers, paraffin workers, and chimney sweeps. The crude petroleum has a particularly irritating effect upon the skin, especially around the hair follicles. These are found to be filled with dark, spiny plugs. Not infrequently keratoses form, and later cancerous changes occur. In chimney sweeps the scrotum is usually affected, due to the collection of soot in the rugae of the skin. This frequently results in death from lymphatic involvement. Cancer has also been recorded as occurring in gardeners who use soot in the course of their work.

*Wende: Jour. Cutan. Dis., 1908. xxvi, 531.

*Schamberg: Jour. Cutan. Dis., 1910. xxvlii, 644.