NOTES ON TWO IMPORTANT ALKALOIDAL REACTIONS. 39 



filtering, adding ammonium hydroxid to the filtrate, and again 

 filtering, the alkaloid may be obtained in a very pure condition, by 

 shaking out with chloroform. 



The writer was unable to confirm the reactions obtained by Beck- 

 mann with the alkaloids of veratrum veride. 



The similarity in the reactions of yoliimbin and strychnin are of 

 interest, as the drug containing the former alkaloid has of late been 

 exploited as a remedial agent for the same purposes for which 

 strychnin has been used. It has been claimed to possess aphrodisiac 

 properties, and might well be suspected hi mixtures advertised for 

 tonics and the like. When working with small quantities the two 

 reactions of yohimbin were so much like those given by strychnin 

 that one could not draw any conclusion as to which alkaloid was 

 present. In the case of the oxidation reaction the play of colors was 

 different, however, pure yohimbin giving first a purple, then a red- 

 dish shade changing to olive green, and if a large quantity was present 

 the color was indigo blue, which soon changed to olive green. The 

 reaction with ammonium vanadate was so nearly identical with that 

 given by strychnin that no distinction could be drawn with any 

 safety. With nitric acid and alcoholic potash a purple color appeared 

 at once changing to a reddish shade, and with large quantities the 

 purple changed to a chocolate which became black on warming. 



Yohimbin forms very few salts which have any characteristic form 

 under the microscope, while those given by strychnin are well defined 

 and can be distinguished readily. Furthermore, yohimbin does not 

 act the same as strychnin physiologically, neither does it possess the 

 mydriatic properties of the belladonna alkaloids. It does not resem- 

 ble the coca alkaloids further than by giving the purple color with alco- 

 holic potash, for on evaporation of the solvent it is left as a solid 

 mass, while the coca bases remain in a semiliquid condition for some 

 tune. It is further distinguished from cocain by not giving the ethyl 

 benzoate test nor the characteristic crystalline picrate. 



There is little danger of confusing strychnin with the principle 

 of colocynth which gives the purple color with sulphuric acid and 

 bichromate. With regard to the alkaloids of hydrastis, gelsemium, 

 and sanguinaria, none of these give the Vitali reaction, and there are a 

 number of well-defined reactions for these substances which have 

 been fully described. (With ammonium vanadate berberin gives a 

 red soon changing to plum color, and gelsemium a magenta changing 

 to blue green.) In connection with the alkaloids of gelsemium, it 

 might be noted that a mixture of the same with strychnin would, as 

 far as the tests in question are concerned, give practically the same 

 reaction as a mixture of atropin and strychnin, and as gelsemium has 

 the property of dilating the pupil of the eye the physiological tests 

 would not serve as final proof. Recourse must be had again to other 



