POISONS. 231 



It is also to be observed that a very slight degree 

 of over-poisoning paralyzes the transmitting system 

 as well as the responding one ; so that if any one 

 should repeat my observaticm, I must warn him 

 ajfainst drawinor erroneous conclusions from this 

 fact. Let him use weak solutions with prolonged 

 soaking, and by watching when the voluntary 

 motions in the poisoned half first cease, he need 

 experience no difficulty in obtaining results as 

 decided as it is possil)le for him to desire. 



12. Cyanide of Potassium. — On Sarsia the first 

 effect is to quicken the contractions and then to 

 enfeeble them. The animal assumes an elongated 

 form, as already described under atropin. Spon- 

 taneity ceases very rapidly even in weak solutions ; 

 and for an exceedingly short time after it has done 

 so, the bell continues responsive both to tentacular 

 and to direct stimulation. For a long time after 

 the bell ceases to respond to any kind of stimula- 

 tion, the nervous connections between the tentacles 

 and between the tentacles and manubrium remain 

 intact, as also do the nervous connections of these 

 organs with all parts of the bell. This interesting 

 fact is rendered apparent, first, by stimulating a 

 tentacle and observing that all the four tentacles 

 and the manubrium respond ; and, second, by irri- 

 tating any part of the neuro-muscular sheet of the 

 bell, and observing that while the latter does not re- 

 spond both the tentacles and the manubrium retract. 

 Recovery from this stage occupies several hours. 



In the case of Tiaropsis the convulsions are, as 

 usual, more pronounced, being marked by the occur- 



