968 EXPERIMENTS OF MAGENDIE AND DELILLE. 



applied nearly a dram of concentrated prussic 

 acid to the brain of a horse, laid bare by means 

 of the trephine, without the slightest symptoms of 

 poisoning being produced : that Magendie and 

 Delille divided all the parts of the thigh of a 

 dog, except the crural artery and vein, which 

 were dissected quite clean, and freed from their 

 cellular coat, to maintain the connexion of the 

 limb with the trunk when two grains of the 

 upas ticuti were inserted into a wound in the foot, 

 the action of which was as rapid as if the limb 

 had not been previously injured, the first symp- 

 toms showing themselves in four minutes, followed 

 by death in ten minutes. 



We are therefore bound to admit with Miiller, 

 that the general effects of poisoning are produced 

 by the entrance of noxious substances into the 

 circulation, through which they operate upon the 

 brain and nervous system.* He further states, 



* A still more decisive proof that poisons operate on the solid 

 tissues through the medium of the fluids is, that they destroy the 

 life of plants, which have no nervous system, as when they are 

 placed in air containing small proportions of sulphurous, nitrous, or 

 hydrochloric acid, ammonia, carbonic oxide, olefiant gas, or in 

 solutions of the vegetable, animal, and mineral poisons. This has 

 been fully demonstrated by the experiments of Macaire, Turner, 

 Christison, and other physiologists ; who have also found that 

 the Mimosa Pudica and the Berberis Vulgaris are killed much 

 sooner by hydrocyanic acid than by solutions of opium, corrosive 

 sublimate, arsenic, and arseniate of potash. But as the circulation 

 of plants is less rapid than that of warm blooded animals, so does 

 it require a longer time for poisons to extinguish their vitality. 



