S-2 Campbof. [Book VI It, 



campfior with th<? affiftance of heat, and depofit cryftals 

 in the form of a beautiful vegetation by cooling. A 

 peculiar acid is formed by the diftillation of nitrous 

 acid wich this fubftance. Camphor has been obtained 

 in fmall quantities from the roots of zedoary, thyme, 

 rofemary, iagey anemony, and other vegetables, by 

 diftillation. It is obfervabfc, that all thefe plants 

 afford a much larger quantity of camphor, when the 

 fap has been fuffered to pafs to the concrete ftate 

 by feveral months drying. Thyme and peppermint, 

 flowly dried, afford much camphor ; and M. Achard 

 has obferved, that a fmell of camphor is difengaged 

 when volatile oil of fennel i-s treated with acids., M. 

 Chaptal concludes, from thefe and fome other facts of 

 the fame kind, that the bafis of camphor forms one of 

 the conftituent parts of fome volatile oils, in which it 

 exiils in the liquid flate, and does not become con- 

 crete, but by combining with the bafis of vital air. 



The camphor of commerce is obtained from a 

 fpsc'res of laurel which grows in China, Japan, and in 

 the iOands of Borneo, Sumatra, Ceylon, &c. The 

 tree which produces it fometimes contains it in fo 

 krge a quantity, that it need only be cleft, in order to 

 obtain very pure tears of camphor, of confiderable 

 fize. The roots of this tree afford camphor in by far 

 the greateft abundance,' but it is alfo procured from 

 the branches, trunk and leaves. The method of ob- 

 taining the camphor is by diililling the different parts 

 of the tree with water. The alembic in which the 

 operation is performed is covered with a capital or 

 head filled with ftraw. On the application of a fufficient 

 heat, the camphor is fublimed in fmall greyifh grains, 

 which are afterwards united into larger mafles. The 

 camphor in this ftate is impure ; it is purified after 

 being brought to Europe, principally in Holland, 

 where it undergoes fublimatiori in low flatrbottorried 



glafs 



