and its Alkaloid Conia. 387 
quickly contracts a dark brown colour, and is slowly resolved in- 
to a resinous matter, with the disengagement of ammonia. This 
change takes place more promptly under the co-operation of 
heat ; but even at common temperatures it is so apt to ensue, that 
unless the alkaloid be kept very carefully excluded from the air, 
discoloration will be accomplished in a few hours. When heat- 
ed with water it readily distils over at the temperature, of Pal Be 
in the same manner as the volatile oils; but its boiling point is 
370° Fahr. It cannot be distilled either alone or with water, 
without a considerable part being decomposed and converted 
into a resin. Like other vegetable alkaloids, it is an azotized 
principle ; and according to an analysis by Lzzzze, it is composed 
of Carbon 66.91, Hydrogen 12.0, Oxygen 8.28, and Azote 12.8.* 
By the process mentioned above, conia may be obtained from 
the leaves of hemlock collected immediately before or during in- 
florescence of the plant. It exists, however, in much larger pro- 
portion in the seeds when fully developed, but still green. Even 
in them the quantity is small: from forty pounds I obtained 
about 22 ounces of hydrated conia. GriceEr states that he ob- 
tained a still larger proportion from the ripe seeds ; a result, how- 
ever, which has not been confirmed in the trials I have made. 
It is very probable that a much larger proportion exists in 
both the leaves and seeds than has yet been obtained. For at 
every stage of the process where heat is applied, however care- 
fully the heat may be managed, it is evident, from the abundant 
formation of ammonia, that much of the alkaloid is decomposed. 
An important fact observed by Gricer is, that the dried 
leaves of hemlock and some extracts of their juice do not contain 
any conia. This observation I have also had occasion to make 
in regard to various extracts. It is interesting, in relation to the 
well known circumstance that the greatest discrepancy prevails 
among medical men as to the activity of hemlock, not. merely 
as a remedy but even also as a poison. ‘T'wo drachms of extract 
* Magazin fir Pharmacie, xxxvi. 161. 
VOL. XIII. PART II. 3D 
