368 PROCEEDINGS OF THE ACADEMY OP 



first increased and afterwards decreased in frequency. Sooner or 

 later, as the drug impresses the system, the pupils dilate. In some 

 persons these symptoms ai-e accompanied, rarely preceded, by 

 symptoms of gastro-intestinal irritation, nausea, and rai*ely vomit- 

 ing. If the dose be a poisonous one, we have, in addition to these 

 sj r mptons, total failure of voluntary motion and convulsive move- 

 ments occurring (vide a case of poisoning by hemlock leaves 

 reported by Dr. Bennett in Edin. Med. and Surg. Journ. for 1845). 

 A close physiological study of conia can best be made by inves- 

 tigating its effects on the different s}'stems, seriatim, and this 

 method I shall endeavor to follow. 



Physiological Effects on Vegetables. 



Worcet (Amer. Chera. et Phys. xxix. 21, 9) placed a haricot 

 plant (Phaseolus vulgaris) in a solution of five grains of the 

 extract of hemlock; in a few minutes the two lower leaves curled 

 at their extremities ; the next day they were yellow and subse- 

 quently died. The experiments of Schubler and Zeller (Schwei- 

 ger's Journ. f. d. Chem. B. 1, S. 54) confirm this poisonous action 

 of the extract. The same results were obtained in several experi- 

 ments made by the writer. 



Exp. 1. 11.55 A. M., placed two plants (Ailanthus glandulosus) 

 of equal age, growth, etc., in separate bottles ; bottle number one 

 containing a seven-grain solution of extract of hemlock, while bot- 

 tle number two contained an equal quantity of pure water. 3.05 

 P. M., the plant placed in bottle number two is in as good condi- 

 tion as when first placed there, while the plant in bottle number 

 one is drooping. 5.30 P. M., the lower leaves of the plant in the 

 hemlock solution are curled at their extremities, while the plant 

 in water is still in an excellent condition. 9.30 P. M., the plant 

 in water is still unchanged, but the lower leaves of the other plant 

 are more curled than before, while the upper leaves and branches 

 hang down the sides of the bottle. The next day at 6. A. M. the 

 lower leaves of the plant in the hemlock solution were dry and 

 brittle, while the other plant remains unchanged. On the third 

 da} r at 10.30 P. M., the entire plant which was in the hemlock 

 solution was dry ami brittle, while the plant which was placed in 

 water had undergone little or no change. 



Exps. 2 and 3 gave identical results. 



