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 212°, 

 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 Liebig, 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 2^ ounces of hydrated conia. Geiger 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 Geiger 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. Two drachms of extract 



* Magazin fur Pharmacie, xxxvi. 161. 

 VOL. XIII. PART II. 3 D 



