992 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[June 14, 1873. 
Similar congeries of cells occur in a 
rent functions. _ 
few otlier leaves, Tout are more easily seen here than 
in any other leaf that I have examined, excepting, 
perhaps, the leaf of Tropcelum magus. 
A somewhat complete examination that I have 
made of the colouring-matters of the hark and leaves 
must stand over for the next chapter. 
(To be continued.) 
CHEMICAL EXAMINATION OF THE BARK 
OF THE AZADIRACHTA INDICA * 
BY J. BROUGHTON, 
Government Quinologist. 
The use of the hark of this well-known tree, the 
Azadirachta Indica, generally called the Nim tree, is 
quite general throughout the whole of India as a 
tonic and febrifuge. It is generally employed in the 
form of a decoction, though sometimes as powder, 
and has been stated by certain English authorities to 
have the same febrifuge qualities as cinchona bark. 
The taste of the bark is intensely bitter ; the inner 
layer, or liber, is however by far the bitterest. The 
tree being very handsome, and the wood of value, it 
is well known in avenues ; the plants generally bear¬ 
ing marks of having been robbed of their bark for 
medicinal use. The pinnate leaves have also an in¬ 
tensely bitter taste, and are employed in native 
medicine, though not as a febrifuge, being used as a 
poultice externally, and are said to have a powerful 
effect in preventing glandular tumours from coming 
to maturity. They are also employed by natives in 
their fresh, green state to cover the bodies of patients 
suffering from small-pox, though I believe this is 
clone rather from a religious than a medicinal mo- 
Tlie seeds yield a considerable amount of oil, 
v hic.h has also a strong, bitter taste, is used for lamps 
and in medicine. The roots are said to have vermi¬ 
fuge properties, but I have not examined them. The 
main virtues of the tree reside in the bark. 
The investigation has been a matter of much 
labour and difficulty, from the circumstance of the 
bitter principle having scarcely any definite qualities, 
it being a neutral resin. It is slightly soluble in 
water, and hence the decoctions of the bark are in¬ 
tensely bitter, though water will not extract the 
whole present. To obtain it in purity the bark is 
exhausted with spirit of about 60 per cent., the fil¬ 
tered tincture precipitated with water, the dried pre¬ 
cipitate again exhausted with benzol, again evapo¬ 
rated, again exhausted with carbonic disulphide 
then by dry ether, and finally by absolute alcohol 
I he last exhaustion causes the separation of a small 
amount of a white transparent substance, crystallizing 
m fine needles, which is quite insoluble in water, has 
no taste, and consists of carbon, hydrogen, and oxy¬ 
gen. Obtainable in but small quantities, it has not 
been satisfactorily analysed, and has the general cha¬ 
racters of a crystalline fat, though fusing at 175° C. 
It is certainly not the effective principle of the bark 
nor an alkaloid. 
The resin purified by the successive solvents is a 
dark brown, somewhat soft resin, of agreeable smell 
resembling that of the bark. It is slightly soluble 
in water,. and entirely in all the foregoing solvents 
but not in fixed oils. In any dilute solution its 
bitter taste is strong, but not disagreeable. It is 
soluble in strong boiling solutions of the fixed alka¬ 
lies, from which acids again precipitate it apparently 
altered, likewise in strong sulphuric acid, by which 
it is also altered. It fuses at 92° C. 
The determination of its true chemical formula 
has been a matter of great difficulty and labour, from 
the circumstance of its refusal to combine with other 
substances in a definite manner. It was finally 
determined by the discovery of a nitro-compound 
which yielded a silver salt, not, however, crystalline. 
From the analyses of these I ascribe to the resin the 
formula C 36 H 50 O u . Its nitro-compound is formed 
in the usual manner by nitric acid and precipitation 
with water, is yellow, uncrystallizable, somewhat 
soluble in water, more readily in alkalies, and having 
the formula C 36 H 4G (NO; 4 O n . 
The resin is, therefore, not in any respect an alka¬ 
loid, as it contains no nitrogen. Its chemical consti¬ 
tution appears to me scarcely to confirm the ascribed 
antiperiodic febrifuge qualities of the bark, though 
doubtless, the bitter solution of the resin may be a 
good tonic. If required for medicinal purposes, it 
will be most conveniently employed in alcoholic so¬ 
lution. As the. bark varies very considerably in its 
content of the bitter resin, a direct tincture would be 
unsuitable, but the impure resin, after the applica¬ 
tion of benzol in the foregoing process of preparation, 
would be fit for solution in alcohol and employment 
in medicine. 
It is singular that native physicians never appear 
to have employed a tincture of the bark instead of 
an aqueous decoction. From some conversation I 
had with a native physician in Bengal, I believe it 
is the native religious dislike in that country to the 
use of alcohol which has prevented its use for this 
purpose. 
The leaves contain a small amount of bitter sub¬ 
stance of a similar nature, but which is far more 
soluble, in water. The same substance is also con¬ 
tained in the bark in addition to the one described. 
It has very similar properties to the resin, of which 
it is a hydrate. No peculiar alkaloid is contained in 
the leaves. The oil contains a small amount of the 
bitter substance of the leaves, not the resin of the 
bark. The powerful smell of the tree is well known, 
but it is hot due to the presence of a sulphuretted 
oil, as has been surmised; indeed, I have not sue-, 
ceeded in obtaining an essential oil from the tree. 
If the bark is distilled with water, the distillate has 
the perfume of the tree, but no oil is perceptible, 
though it has the power of decolorizing potassic per¬ 
manganate. 
A condensed account of our present knowledge of 
the therapeutics and chemistry of Azadirachta In¬ 
dica is to be found in the Indian Pharmacopoeia, 
pp. 53 and 443, from which, however, I differ in 
some points. 
WHAT IS TEE TRUE COLOUR OF PULVIS CRETiE 
AROMATICUS l 
BY ARCHIBALD PATERSON. 
* From the Madras Monthlxj Journal of Medical Science. 
W ith. an article of such importance as Pulvis Cretse 
Aromaticus, one which is so frequently prescribed, and 
which forms the basis of that useful remedy, aromatic 
powder of chalk and opium; one would very naturally 
suppose, that a question such as the heading of this paper 
asks, would be altogether uncalled for. 
