DRYOBALANOPS CAMPHORA. ORD. Dipterocarpez. 127 
The camphor which is the produce of this tree, is little known in Europe : 
the greater part is said to be carried to China, where it fetches a very high 
price. Camphor is imported into this country in casks and chests, chiefly 
from Japan, and comes in small granular, or friable masses, which are after- 
wards purified by sublimation. | a tp 
Chemical Properties, &c. of Camphor. Pure Camphor has a strong, pecu- 
liar, fragrant and penetrating odour, and a bitter, aromatic, pungent taste, 
accompanied with a sense of coolness; it is white, pellucid, unctuous to the 
touch, and friable; breaking with a shining, foliated fracture, which dis- 
plays a crystalline texture; notwithstanding its friability, it is extremely 
difficult to be pulverised, requiring, for this purpose, to be slightly moistened 
with alcohol. It is not altered by exposure to the atmosphere, but if it be 
not kept in well stopped vessels, especially during warm weather, it evapo” 
rates completely. It is lighter than water, (sp. gr. 0,9887) and nearly inso- 
luble in that fluid, but communicatés to it a certain portion of its odour.* 
It melts at a temperature of 88°, (Fah.) boils at 400°, and sublimes in close 
vessels, crystallizing unchanged in hexagonal plates; or, according to Mr. 
W. Philips, into flat octohedrons. It readily ignites, burning with a brilliant 
flame, and giving out much smoke. Alcohol, ether, the sulphuric and nitric 
acids, a little diluted, and the muriatic, strong acetic, and fluoric acids, dis- 
solve camphor, as also the fixed and volatile oils: it is separated unchanged 
- from these solutions, by the addition of water. It is decomposed by the con- 
centrated sulphuric acid, forming artificial tannin ; and by repeated distilla- 
tion with nitric acid, it is converted into camphoric acid. It unites with the 
hardest resinous substances, converting them into soft, tenacious masses. 
The alkalies have but little action on camphor; when mixed with clay, and 
distilled in close vessels, it is decomposed into a volatile oil and charcoal ;+ 
from this, it would appear to differ from the essential oils, only in containing 
a larger proportion of carbon. Dr. Thomson gives its component parts as 
follows :—carbon 6,875; hydrogen 1,250; oxygen 1,000. 
Camphor was for some time supposed to be a resin, and was so designated 
by the Dublin College ; but chemists have now agreed that itis a vegetabl 
* According to Cadet, one French pint of water dissolves about 16 grs. of camphor, 
which are again precipitated by pure potass.—Ann. de Chimie, \xii. 132. 
+ According to Bouillon la Grange, 45,856 of volatile oil, and 30,571 of charcoal. 
