602 
ON THE PREPAKATION OF CONIUM. 
them in thin layers alternating with layers of fine sand in a percolator, f 
of water containing 120 grains of caustic potash was poured upon them, and 
maceration allowed for 24 hours. The aqueous solution was then displaced 
by f ^viii of dilute alcohol (equal parts of rectified spirit and water), and 
maceration allowed for 24 hoars more. The spirituous fluid was next dis¬ 
placed by water acidulated with sulphuric acid, and percolation continued as 
long as the running fluid possessed colour, f 5xxii of very dark greenish- 
brown fluid was thus obtained. A little more acid was added to produce 
exact neutralization of the alkali, and the turbid fluid filtered. Chlorophyl 
and sulphate of potash, destitute of conia or any of its salts, remained on the 
filter. The filtrate was evaporated over a water bath at a temperature under 
160° F., until about 5v of dark brown extract, of treacly consistence, re¬ 
mained. While still warm, this was rubbed up with f5v of solution of caustic 
potash (1 part (HO, KO), 3 parts (HO)). A very faint odour of conia was 
evolved. The mixture was transferred to a long tube, and shaken at intervals 
with an equal bulk of sether. The aether assumed a yellowish-green colour. 
After 24 hours the aethereal solution was decanted, and the extract washed 
with fresh portions of aether as long as it continued to dissolve anything. 
The mixed aethereal solutions were then distilled. Half a grain of a clear, 
deep sap-green, thick, oily fluid, lighter than water, remained. It possessed 
a mint-like odour mixed with that of conia. To the tongue it was almost as 
bitingly acrid as conia itself, but in minute quantity it produced, like oil of 
peppermint, a sharp cooling sensation. Its taste was bitter, and it possessed, 
in an intense degree, the nauseous flavour of the dried leaf or its tincture. 
It was in fact a mixture of conia and the oleo-resin of the plant, coloured by 
chlorophyl. It imparted to water a strong alkaline reaction. Mixed with 
water acidulated with sulphuric acid it refused to dissolve, but the aqueous 
fluid obtained a tinge of colour, and, when evaporated nearly to dryness, a 
dark film of syrupy fluid remained, which, when mixed with a little solution 
of caustic potash, evolved a distinct odour of conia. 
II. An ounce avoirdupois of the mixed leaves were taken and mixed with 
f^vss of water and f ^ss dilute sulphuric acid P. B. Maceration was allowed 
for seven days at a temperature of 50° F. The fluid was then displaced 
by water, f^x of bright sherry-coloured infusion was thus obtained. This 
was neutralized exactly by HO, KO, and filtered. A modification of chlo¬ 
rophyl, which gave a deep yellow colour with potash, and sulphate of potash, 
both free from conia or any of its salts, remained on the filter. The filtrate 
was treated as was that of Ho. I, and the extract in like manner supersatu¬ 
rated with potash and washed with sether : a little less than half a grain of 
bright pale greenish-brown oily matter remained. It possessed a powerful 
odour, compounded of conia and the peculiar odour of the leaves with a 
minty addition. It smelt more of conia and less of mint than the product 
described under Ho. I. Its taste was intensely biting, like that of conia 
itself, leaving a flavour of tobacco and peppermint, and the rank ta§te of the 
dried leaves. Treated with sulphuric acid the oily fluid partly dissolved, and 
the filtered solution manifested a purple tinge on evaporation, and furnished 
a little brown syrupy extract, which, upon the addition of potash, evolved a 
strong odour of conia, a distinct trace of which was obtained from the mix¬ 
ture by the aid of aether. 
It appears from the foregoing experiments that the dried leaves do, when 
carefully prepared and preserved, retain a trace of conia ; and it is equally 
conclusive that the quantity is much too small to furnish an efficient prepa¬ 
ration. 
III. In order to make my investigation complete, I subjected the leaf-stalks 
—primary, secondarj^, and tertiary—to the same process as that described in 
