16 ODOROGRAPHIA. 
which still retain a very considerable portion of alcohol. Ambrein 
thus obtained possesses an agreeable odour, but by repeated solution 
and crystallization it loses this. It is destitute of taste, and does 
not act on vegetable blues. It is insoluble in water, but dissolves 
readily in alcohol and ether, and in much greater quantity in those 
liquids when hot than when cold. It melts at 30° C., softening 
at 25° C. When heated above 100° C., it is partly volatilized and 
decomposed, giving off a white smoke. It does not seem capable 
of combining with an alkali or being saponified. When heated 
with nitric acid it becomes green and then yellow, eliminates 
nitrous gas, and is coverted into an acid which has been called 
ambreic acid. Ambrein is perhaps impure cholesterin, which sub- 
stance it greatly resembles in its properties. Pelletier * found it 
to contain very nearly the same proportion of elements in com- 
bination. 
Whilst on the subject of fishes and insects, it may be opportune 
to remark that the odour emitted by the flesh of the Grayling has 
been likened to that of thyme; this is attributed to a habit of 
this fish of feeding on the Gyrinus natator, an insect of so strong 
an odour that when several of them are collected together they 
may be scented at a distance of 500 paces. Many insects are 
aromatic; there are ants in Bahia which, when squeezed, give off 
a strong smell of lemons. 
The food of animals undoubtedly affects the odour of their 
secretions and excretions. It has been remarked that the Musk 
Deer only frequents districts in which the birch-tree is found ; 
the reason of this is not apparent, but the animal certainly fre- 
quents localities where certain plants of the larkspur species 
thrive, species which possess such a strong odour of musk that 
the peasants of the locality believe the odour of this animal to be 
due to feeding on this plant; a belief which may be wrongly 
conceived, because the Musk Deer is found in other localities 
where the plant does not exist. Still, it is a curious coincidence. 
To quote from the ‘ Flora Indica’ of Hooker and Thomson : 
writing on the botany of the Himalayas :— 
“Owing to the great power of the sun there is scarcely any 
vegetation even at 15000 feet; above that, though plants may be 
* Ann. Ch. Pharm. vi. p. 24. 
