CAMPHOR

an organic compound of penetrating, somewhat musty aroma, used for many centuries as a component of incense and as a medicinal. Modern uses of camphor have been as a plasticizer for cellulose nitrate and as an insect repellent, particularly for moths. The molecular formula is C10H16O. Camphor occurs in the camphor laurel, Cinnamomum camphora, common in China, Taiwan, and Japan. It is isolated by passing steam through the pulverized wood and condensing the vapours; camphor crystallizes from the oily portion of the distillate and is purified by pressing and sublimation. Since the early 1930s camphor has been made by several processes from the compound a-pinene. Camphor belongs to a group of organic compounds defined as terpenoid ketones. The structure and the reactions peculiar to it were important problems of 19th-century organic chemistry. The pure compound is a white, waxy solid that melts at about 178179 C (352354 F).