2 
THE AUSTRALASIAN JOURNAL OF PHARMACY. 
Physical Characters. — All eucalypts cast their bark annually, the leaves are 
evergreen ; the petiole is half twisted, so that the plane of each leaf is 
parallel to the axis of the tree, allowing thereby free action on both sides to 
sunlight and to the air currents. Translucent oil cells abound in all the 
leaves, and in many species the cells are visible to the naked eye ; the leaves 
also have stomata on each side, and the oil cells run through. The roots are 
very dispersive, and have rootlets in great abundance. 
Chemical Constituents are not only those usually met with in all ligneous 
vegetation, but contain also a volatile otto or oil, varying in composition in 
some species ; a volatile acid, termed eucalyptic acid ; a bitter principle, in an 
amorphous condition, strongly hygroscopic, termed eucalyptene ; a gum resin, 
varying in kinic or catechuic characteristics. The volatile oil is met with only 
in the leaves and the fruit vessels; the other principles in all parts of the 
tree. 
Therapeutic Inquiry and Errors. — It must always be borne in mind, in 
any inquiry into the therapeutics of this vegetation, that there are about 150 
species, and as in the case of the genus cinchona, in which only a third of its 
varieties supply the cinchona barks of commerce, and each variety differs in 
quantity of the alkaloids, and in their chemical composition, so in like manner 
the eucalypti vary in active principles, especially in essential volatile ottos. 
Owing to the free growth and pretty leaf appearance of the eucalyptus globulus 
(blue gum) during the first three years of its growth, together with its having 
become acclimatised in Europe and other parts of the world, this species has 
been referred to by writers and medical men as the only species worthy of 
notice ; in fact, they have almost ignored the consideration of any other variety. 
This error has led to much confusion ; hence in many medical and other scien- 
tific journals of those countries any therapeutic or sanative result recorded is 
generally credited to eucalyptus globulus, when, as is well known to many in 
Victoria, some other variety was under consideration. In like manner, we may 
refer to the eucalyptus nostrums : no matter how prepared or of what compo- 
sition, they are sure to be stated to be obtained from the “ eucalyptus 
globulus.” 
Chief Medicinal Species. — For supplying the essential oils of commerce — the 
amygdalina, globulus, and oleosa ; the volatile acid — rostrata and globulus ; the 
bitter principle — globulus and stuartiana ; the kino and catechu resins — obliqua, 
leucoxylon, marginata, and rostrata. The result of long observation and experi- 
ment is that the volatile element is the base of all the products and educts 
just mentioned, and for the following reason : That those species which are 
great in the production of oil supply it (by the peculiar leaf formation) 
vigorously to the atmosphere, allowing but little time for the production of 
substances, such as resins and vegetable acids, which require the absorption of 
oxygen by the leaf to form them. On the other hand, those species less 
vigorous in oil production allow time for the purpose, hence they become well 
stored with resin and acid, both in the wood and in the bark. 
The Products and their Medicinal Uses. — Eucalyptic acid is obtained by 
fractional distillation of the mother liquor of any of the eucalypts. It is 
persistent in aroma, and has been known to retain its identity after exposure to 
the air for many years. It is supposed that the fact of the red gum timber 
containing this acid abundantly is the reason of its not being attacked by the 
“ Teredo navalis,” when used for piles in the erection of sea jetties. It is a 
powerful antiseptic. 
The Crum Pesins are generally collected from many species ; some supply 
a ruby- coloured kino (as per sample), others again that of catechu — the former 
