272 Indian Forest Records. [VoL. 1, 
obtained as a crystalline substance by extraction with water or by steam 
distillation from the wood of Cinnamonum camphora, the well-known 
camphor laurel of Japan and China. The product obtained by distil- 
lation is afterwards refined by sublimation. 
Co mm on camphor is a colourless semi-transparent substance of a 
granular and crystalline structure. It volatilizes readily at ordinary 
temperatures, emitting a peculiar penetrating aromatic odour. It has 
a bitter, pungent taste. Its specific gravity at 0°C. is I'O, and 0‘9853 
at 18°C. It is but slightly soluble in water (1 in 1,200) ; and when thrown 
in small fragments on the surface of that liquid, displays peculiar gyratory 
movements, which, however, are not executed in the presence of even 
very small quantities of oil. Being of a tough and wa:ty structure it is 
very difficult to pulverize, but the pulverization is readily effected by 
means of a little alcohol or sugar, ether or choloform. It is readily 
soluble in organic solvents, e.g., alcohol and ether. 
It melts at 175°C., and boils and distils without change at 204°C. 
It is an inflammable .substance, and burns with a smoky flame. 
Common camphor is an optically active substance, its alcohohc solution 
turning the plane of polarisation to the right. On this accoimt it is 
sometimes in scientific works referred to as d-camphor.^ 
Principal reactions of camphor. — (1) Camphor is very energetically 
acted upon by dehydrating agents such as phosphoric acid anhydride, 
sulphuric acid and zinc chloride. On heating mth phosphoric acid 
anhydride, it is changed into a hydrocarbon called cymene or cymol by 
losing the elements of water, thus : 
CioHi60=H20-1-CioHi4 
Camphor. Cymol. 
Sulphuric acid and zinc chloride yield other substances along with cymol. 
(2) Prolonged boiling of camphor with nitric acid results in the for- 
mation of camphoric acid C 10 H 16 O 4 , thus : 
2CioIIi6O“1"3O2=2CioHi0O4. 
(3) Camphor absorbs gaseous hydrochloric acid, forming an oil from 
which it can be readily regenerated by decomposing it with water. 
1 In optics those substances which rotate the plane of polarisation to the right 
are called dextrogyrate or dextrorotatory ; while those which turn it to the left are 
known as laevogyrate or laevorotatory, d camphor means dextrogyrate camphor. 
Likewise, 1 -camphor = Laevogyrate camphor. 
