on the Vegetable Kingdom. 297 



jured by the same treatment, with a solution of sulphate of 

 magnesia, although Professor Carradori of Florence supposes 

 that this earth exercises a poisonous action upon vegetables. 



II. — Vegetable Poisons. 



As most of the poisons from the vegetable kingdom destroy 

 animal life by exercising a particular action on the nervous 

 system, Mr Marcet was anxious to examine their action 

 on vegetables. 



OPIUM. 



On the 10th May, at 9 A. M. a French bean plant was in- 

 troduced by its root into a solution of five or six grains of 

 opium in an ounce of water. In the evening, the leaves be- 

 gan to droop. Next day, about noon, the plant was com- 

 pletely dead, and the leaves withered, without change of co- 

 lour. 



The aqueous extract of nightshade acted exactly like opi- 

 um, but with more rapidity. 



NCX VOMICA. 



On the 9th May, at 9 A. M. a French bean plant was in- 

 troduced into a solution of five grains of the aqueous extract 

 of nux vomica in an ounce of water. At the end of an hour, 

 the plant became unhealthy. At 10 o'clock the leaves had 

 not changed colour until the small branches to which they 

 were attached were bent, and, as it were, broken in the middle. 

 In the evening the plant was dead. 



On the 15th July, Mr Marcet introduced fifteen grains of 

 the above extract, diluted with water, into a cut 1| inch long, 

 made in a lilac tree, about one inch in diameter, as far as the 

 pith. 



On the 28th, the leaves of the two great branches of the 

 tree near the cut had begun to dry. On the 3d April, the two 

 branches were quite dry. The other branches dried in the 

 course of the autumn. 



Both opium and nux vomica produce death in animals, by 



