1874.] the Action of the Chinoline and Pyridine Bases. 433 



obtained by the destructive distillation of coal, or from Dippel's oil, got 

 from bone. G-reville Williams has pointed out that chinoline obtained 

 from coal-tar differs in some respects from, that yielded by cinchonine. 

 In this research the authors endeavoured to ascertain (1) the physio- 

 logical action of the various members of the series ; (2) whether there 

 was any difference in this respect between the members of the series 

 obtained from cinchonine and those got from tar ; and (3) whether, and 

 if so, how, both as regards extent and character, the physiological action 

 of these bases differed from that of the original alkaloidal bodies. 



The bases in both series are difficult to separate from each other ; but 

 this has been done as far as possible by repeated fractional distillation. 

 The salt employed was the hydrochlorate. This, dissolved in water, was 

 introduced by a fine syringe under the skin of the animal. The action of 

 chinoline was tested on frogs, mice, rabbits, guineapigs, cats, dogs, and 

 man ; but as the effects were found to be similar in all of these instances, 

 the majority of the observations were made on rabbits. The experi- 

 ments with the other substances were made on rabbits and frogs. The 

 physiological action of hydrochlorate of chinoline was first examined. 

 Its action was then compared with that of the hydrochlorates of the 

 chinoline series of bases distilling at higher temperatures, including 

 such as lepidine, dispoline, tetrahiroline, &c. In the next place, the 

 physiological action of the pyridine series was studied, beginning with 

 pyridine itself, and passing upwards to bases obtained at still higher 

 boiling-points, such as picoline, lutidine, &c. Lastly, the investigation 

 was directed to the action of condensed bases, such as dipyridine, parapi- 

 coline, &c. ; and the effects of these substances were compared with those 

 produced by the members of the chinoline series and among themselves. 



The following are the general conclusions arrived at : 



1. There is a marked gradation in the extent of physiological action of 

 the members of the pyridine series of bases, but it remains of the same 

 kind. The lethal dose becomes reduced as we rise from the lower to the 

 higher. 



2. The higher members of the pyridine series resemble in physiologi- 

 cal action the lower members of the chinoline series, except (1) that the 

 former are more liable to cause death by asphyxia, and (2) that the 

 lethal dose of the pyridines is less than one half that of the chinolines. 



3. In proceeding from the lower to the higher members of the chino- 

 line series, the physiological action changes in character, inasmuch as the 

 lower members appear to act chiefly on the sensory centres of the 

 encephalon and the reflex centres of the cord, destroying the power of 

 voluntary or reflex movement ; while the higher act less on these centres, 

 and chiefly on the motor centres, first, as irritants, causing violent con- 

 vulsions, and at length producing complete paralysis. At the same time, 

 while the reflex activity of the centres in the spinal cord appear to be 

 inactive, they may be readily roused to action by strychnine^ 



