570 



EFFECT OF COCAINE ON GROWTH OF LUPINUS 



All of the above substances were studied in various concentrations, 

 the object being to ascertain, in the first place, whether they were 

 toxic to the roots at all and if so to determine their limits of toxicity; 

 that is, the minimal concentrations of the drug which produce a re- 

 tardation in growth or other toxic effects. 



EXPERIMENTAL, 



Efect of Cocaine. — Cocaine hydrochloride was employed in the 

 experiments, the chemically pure salt was dissolved in distilled water, 



TABLE I. 



Relation between Concentration of Cocaine Hydrochloride and Growth of Lupine 



Roots. 



and various concentrations of the solution were mixed with equal 

 parts of normal Shive solution, the plants being immersed in the 

 mixture. The results of the experiments are shown in Table I. 

 In the first column are indicated the concentrations of the cocaine 

 hydrochloride expressed as molar, and in the second column are given 

 the equivalents of these concentrations in terms of per cent by weight. 

 In the third column the mean growth increment of the seedlings in 

 the cocaine solutions is indicated as compared with the corresponding 

 normal or control increment, for 24 hours. It will be seen that growth 

 of these roots is affected only by rather strong solutions of cocaine. 



