162 DROSERA ROTUNDIFOLIA. [Chap. IX 



CHAPTER IX. 



THE EFFECTS OF CEBTAIfir ALKALOID POISONS, OTHEB SUBSTANCES 

 AND VAPOURS. 



Strychnine, salts of Quinine, sulphate of, does not soon arrest the move- 

 ment of the protoplasm Other salts of quinine Digitaline Nicotine 

 Atropine Veratrine Colchicine Theine Curare Morphia 

 Hyoscyamus Poison of the cobra, apparently accelerates the move- 

 mente of the protoplasm Camphor, a powerful stimulant, its va]K>ur 

 narcotic Certiiin essential oils excite movement (ilycerine Water 

 and certain solutions rotiird or prevent the subsHiuont action of phos- 

 phate of ammonia Alcohol innocuous, it8 vapour narcotic and poison- 

 ous Chloroform, sulphuric and nitric ether, their stimulant, poison- 

 ous, and narcotic power Carbonic acid narcotic, not quickly poisonous 

 Concluding remarks. 



As in the last chapter, I will first give my experiments 

 and then a brief summary of the results with some con- 

 cluding remarks. 



Acetate of Strychnine. Half-minims of a solution of one part 

 to 437 of water were placed on the discs of six leaves; so that each 

 received ^^ of a grain, or .()C75 nig. In 2 hrs. 30 m. the outer 

 tentacles on some of them were inflected, but in an irregular man- 

 ner, sometimes only on one side of the leaf. The next morning, 

 after 22 hrs. 30 m., the inflection had not increased. The glands 

 on the central disc were blackened, and had ceased secreting. 

 After an additional 24 hrs. all the central glands seemed dead, but 

 the inflected tentacles had re-expanded and appeared quite healthy. 

 Hence the poisonous action of strychnine seems confined to the 

 glands which have absorbed it; nevertheless, these glands transmit 

 a motor impulse to the exterior tentacles. Minute drops (about ^ 

 of a minim) of the same solution applied to the glands of the 

 outer tentacles occasionally caused them to bend. The poison does 

 not seem to act quickly, for having applied to several glands sim- 

 ilar drops of a rather stronger solution, of one part to 292 of 

 water, this did not prevent the tentacles bending, when their 

 glands were excitetl, after an interval of a quarter to three quarters 

 of an hour, by being rubbed or given bits of meat. Similar drops 

 of a solution of one part to 218 of water (2 grs. to 1 oz.) quickly 

 blackene<l the glands; some few tentacles thus treated moved, 

 whilst others did not. The latter, however, on being subsequently 

 moistened with saliva or given bits of meat, became incurve<l, 

 though with extreme slowness; and this shows that they had been 



