630 CAMPHOR 



CAMPHOR 



CAMPHORA. A white crystalline substance obtained from 

 Cinnamomum camphora, purified by sublimation (B.P.). 

 Nat. Ord. Laurineae. 



The camphor laurel is a tall, handsome evergreen, culti- 

 vated in Japan and China, and in many European con- 

 servatories. Its wood and leaves evolve a characteristic 

 odour when bruised, and yield about -^J-^th of their weight 

 of camphor, which is sometimes extracted by dry distilla- 

 tion. 



PROPERTIES. Camphor occurs in solid, colourless, trans- 

 parent masses, of tough consistence. It has a bitter, 

 pungent, cooling taste, and a characteristic, aromatic odour. 

 It floats on water, its specific gravity, varying with the 

 temperature, is about 0*995. Exposed to the air, it volatil- 

 ises ; heated, it sublimes without residue, and burns 

 readily with a bright but smoky flame. It is difficult to 

 powder, unless when mixed with alcohol, ether, or chloro- 

 form. It dissolves readily in ether, in about its own weight 

 of rectified spirit, in one-fourth part of chloroform, four parts 

 olive oil, two parts oil of turpentine, eight times its weight 

 of milk, and in 700 times its weight of water. Camphor 

 (C 10 H 16 0) is a ketone of terpene (C 10 H 16 ) the chief con- 

 stituent of oil of turpentine, chamomile, cardamoms, cloves, 

 hops, juniper, savin, and valerian. Most of these volatile oils 

 contain a small amount of a crystalline substance or stearop- 

 tine which is deposited on standing. The chief of these 

 bodies is camphor. Continuously heated with nitric acid, 

 camphor oxidises, and is converted into camphoric acid 

 (C 10 H 16 4 ). Triturated with chloral hydrate, menthol, 

 phenol, or thymol, it forms a liquid. 



Borneo camphor (C 10 H 18 0) is an alcohol derived from the 

 wood of Dryobalanops aromatica, and is distinguished from 

 laurel camphor by its softness, friability, and opacity, its 

 higher density, and its somewhat alliaceous odour. From 

 Borneo, Formosa, and other parts of China, fluid camphor 

 oils are obtained from several different trees. Artificial 

 camphor (C 10 H 16 HCL) is got by the action of hydrochloric 



