24 
ORIGINAL COMMUNICATIONS. 
fered to cool, separates into two distinct substances. The first 
is of a dark brown colour, very adhesive, insoluble in water, 
but soluble in alcohol and ether. Its taste is warm and aro- 
matic, resembling that of the oil of black pepper, but in an 
inferior degree. Its odour has also some resemblance to that 
of the same principle. When dissolved in a small portion of 
alcohol, it imparts to that menstruum a greenish cast. Its solu- 
tion is not affected by the addition of a solution of gelatin or 
sulphate of iron. The second substance produced is of a red 
colour, brittle, inodorous, slightly soluble in alcohol and in 
ether, but very soluble in water. Its solution is of a brownish 
cast, but on the addition of a solution of the sulphate of iron, 
it is converted to a deep blue. A solution of gelatin forms 
with it a precipitate. 
The same portion of root acted on by the alcohol, was 
digested for some days in water, and the infusion filtered. 
This infusion was not affected by the addition of a solution of 
iodine, alcohol, or a solution of the subacetate of lead; but a 
precipitate was formed on the addition of a solution of gelatin. 
The leaves and the flowers impart to water by decoction, and 
to alcohol and olive oil by maceration, a deep red colour. 
The decoction is precipitated by a solution of gelatin, and of 
the sulphate of iron; but is not affected by the solution of 
iodine, or of the subacetate of lead. Carefully evaporated, it 
yields an extract having an odour much resembling that of the 
horehound. The tincture carefully evaporated, yields two 
substances precisely resembling those obtained by the same 
process from the tincture of the root, but in a much larger pro- 
portion. The oleaginous infusion acquires, besides its red 
colour, a slight acrimony, which is perceptible on a drop or 
two of it being placed on the tongue. I have perused several 
writers on the materia medica, who have treated concisely of 
the H. perforatum, and the majority of them agree in attri- 
buting its therapeutical agency to the presence of a volatile oil, 
contained in small vesicles, attached to the leaves and the 
petals of the corolla. No accurate description, however, is 
given by them of this oil, or of the amount afforded by a defi- 
