1064 ON THE PHARMACOLOGY OF SOME NEW POISONOUS PLANTS. 



minutes, after which they become flaccid and have spasmodic con- 

 tractions of all the limbs every moment or so, the contractions 

 getting weaker and weaker until they cease. The heart continues 

 to beat regularly for many hours and stops in full diastole. 



There is a great increase of secretion of the skin. 



Frogs that have had less than a lethal dose become very irritable; 

 there is a marked increase of reflex excitability. It is difficult, 

 however, to make them jump ; when one does so it lands upon its 

 belly and this causes a spasm. There is a loss of co-ordination of 

 muscular movement. 



If the brain of a frog be destroyed previous to poisoning with 

 this substance, some convulsions appear but they are not of so 

 violent a kind as when the brain is intact. 



The physiological action of this substance appears identical with 

 that of picrotoxin, the active principle of Coccuhcs, a genus of the 

 same order as Stejyhania, 



As picrotoxin is an easy substance to separate I shall ascertain 

 whether it is present in this plant, and add the result of the chemical 

 investigation as this paper passes through the press. 



Note. — I failed to obtain picrotoxin from this plant, but found 

 that the active principle was a totally different substance. It 

 appears to be an alkaloid, and may be separated in the following 

 manner : — Bruise the rhizome in an iron mortar, macerate for 

 several days in rectified spirit of wine, decant the tincture and 

 allow it to evaporate. Treat the extract with water, filter, add 

 some neutral lead acetate, digest ten minutes and set aside for 

 several hours, filter, remove excess of lead with sulphuretted 

 hydrogen and evaporate to a syrup, add a very little liquor 

 potassse, and shake out the active principle with anhydrous ether. 



It is thus left as a colourless, non-crystalline substance, like bits 

 of gum arable. It has a peculiar smell and is bitter, neutral to 

 litmus, slightly soluble in water but very soluble in alcohol, easily 

 soluble in acidulated water, and the resulting salts are apparently 

 non-crystalline ; they set as varnishes. 



It is exceedingly poisonous, and the symptoms produced aie 

 those of the crude extract. 



