Effect of Opiates on Memory and Behavior. 163 



cooled in a dish of ice water. It is then placed in the boiling water 

 bath for 2 minutes and immediately cooled in ice water, after 

 which 3 drops of 5 per cent, solution of guiacol are added. With 

 pure lactic acid solutions a rose color is developed which remains 

 stable and clear for some time. The maximum color is developed 

 in the blood filtrates in about 20 minutes and it must then be read 

 against standards prepared with known amounts of lactic acid 

 (conveniently prepared from zinc or lithium lactate). An appre- 

 ciable color is produced by 0.01-0.02 mg. of lactic acid. The 

 colors may be compared in small flat-bottomed Nessler tubes, or the 

 concentrated acid solutions may be compared in the Duboscq 

 colorimeter without injury to the cups. On prolonged standing a 

 turbidity develops in the blood filtrates which renders it impossible 

 to read them accurately. 



87 (1547) 



Effect of opiates on memory and behavior of albino rats. 



By D. I. Macht and C. F. Mora. 



[From the Pharmacological and Psychological Laboratories of the 

 Johns Hopkins University.] 



Studies were made by the authors on the behavior of white 

 rats in Watson's circular maze. A total number of eighteen rats 

 was used. The animals were trained to find their way through 

 the intricate labyrinth of the maze in the shortest period of time 

 without making any error. They were then injected with the 

 various drugs studied, and their behavior, both immediately 

 after injection and for some time afterwards, was observed. The 

 experiments on the rats in the maze gave data concerning the 

 memory habit of the animals, their activity, and the coordination 

 of their movements after the administration of the narcotics. 

 A large number of experiments was performed on different rats, 

 and the effects of the following opiates were studied: Morphin, 

 codein, thebain, narcotin, narcein and papaverin. In addition 

 to the individual alkaloids, the following combinations were also 

 administered: pantopon (total opium alkaloids) and narcophin 

 (morphin plus narcotin). 



