3850 ODOROGRAPHIA. 
flower there is a scaly conic bud at the apex, which soon advances 
into a leafy branchlet. 
This tree was included by Linnzus in his species Melaleuca 
Leucadendron, a taller tree with a thick, spongy, black bark, which 
detaches itself in flakes ; its branches, however, are white; no 
doubt the derivation of the word Medaleuca is to be attributed to 
this strange appearance, éAas meaning black and Aeveos white. 
The form and texture of the leaves of M. Leucadendron are very 
variable, as is also the colour of its flowers. It does not yield so 
much essential oil as the M. minor ; but both oils are very similar 
in character and hardly to be distinguished. 
The distillation is conducted in a primitive way and the oil put 
up in beer bottles. 
The oil has a very powerful aroma, reminding of a mixture 
of camphor, cardamoms, and turpentine. The sp. gr. of oil of 
cajeput at 15°°5 C. has been found by West *, on examination of 
14 samples obtained from different sources, to be 0°922 to 0-924. 
In taking the sp. gr. of this oil, it is important to take accurate 
note of the temperature, in consequence of the high expansion- 
equivalent of the oil, which has been found by Cripps + to be 
‘0009 for each degree Centigrade between 13° C. and 23° C. The 
boiling-point of the 14 samples above mentioned was found to be 
174° to 174°°5 C., and copper was detected in all of them. It is 
generally supposed that the pale greenish tinge in oil of cajuput is 
necessarily the result of copper, acquired by contamination with 
the metal of the still, but it has been ascertained that recently- 
distilled cil has a natural and beautiful green tint. 
Professor Tichomirow { examined oil of cajuput spectroscopically 
and satisfied himself that the green colour of a sample that had 
been demonstrated to be free from copper was due to the presence 
of chlorophyllan, or oxidized chlorophyll. As the green colour 
due to chlorophylian may in old oils change to brown, it is probable 
that oil is kept for a time in copper vessels that it may become 
impregnated with the metal, with the intention of causing it to 
retain its beautiful natural colour. Copper may be detected by 
agitating the oil with dilute hydrochloric acid, pouring the liquid 
into a platinum capsule and inserting a slip of zinc ; if copper be 
* Pharm. Journ. [5] xix. p. 235. + Ibid. p. 415. 
{ Pharm. Zeit. f. russl., Aug. 1888, p. 548. 
