98 



PLANT COMPOUNDS 



habit is once formed. Antidotes to morphine poisoning are 

 potassium permanganate, tannic acid, and emetics. 



Fig. 23. — The cultivated variety of the opium poppy. 



(e) Nicotine, C10H14N2, is a colorless liquid turning brown 

 on exposure to the air, with acrid taste. It is one of the 

 most virulent poisons known. In small doses it has been 

 used in medicine as a sedative. It is found in tobacco, varying 

 in amounts from 1 to 8 per cent. The pleasant as well as 

 the exceedingly disagreeable effects of smoking and chewing 



