PRODUCED BY DISTILLATION OF CINCHONINE. 311 



idea which often forced itself upon me, namely, that there might be some basic 

 product besides pyrrol, characteristic of the destructive distillation of nitrogenized 

 organic bodies, because I had no decisive proof; but I may mention that there is 

 a most intimate connection between the volatile bases best known, produced at 

 very high temperatures. For with all the substances as yet examined, such as 

 bones, shale, &c, the complete series of bases homologous with pyridine has been 

 found, and though, in the case of coal naphtha, only picoline has as yet been de- 

 tected, I believe I shall shortly be able to prove, that other members of that series 

 exist in it. It will be seen that, if these views are correct, indigo and piperine 

 ought to yield more than aniline in the one case, and piperidine in the other, 

 which, in the present state of our knowledge, does not appear to be the case ; 

 while, on the other hand, if we study the experimental results yet obtained 

 from coniine, it will scarcely be too much to conclude that it is a mixture. 

 In order to give a decisive answer to the question raised by these facts, it be- 

 comes necessary to examine, somewhat minutely, several of the bases said to be 

 the sole product of the destructive distillation of certain alkaloids, and other nitro- 

 genous bodies ; and the following may be regarded in the light of a small contri- 

 bution to the subject. 



It being evident that a considerable amount of material would be required, I 

 subjected 100 ounces of cinchonine to destructive distillation with potash, by 

 small portions at a time, in an iron alembic, the products being collected in a well 

 cooled recipient, but notwithstanding the large scale on which the experiments 

 were carried on, some difficulty was found in procuring enough of certain portions 

 for examination. 



There were several phenomena observed during the preparation of the crude 

 chinoline, which are not described in the works to which I have had access ; but 

 as these are not immediately connected with the subject under consideration, 

 they need not be further alluded to, except to mention that whatever precautions 

 were taken in the distillation, pyrrol was, nevertheless, constantly found, and ad- 

 hered to the crude chinoline with such tenacity, that it required two days' boiling 

 of the acid solution to effect its complete removal. 



The base was separated from the simultaneously-produced water, by means 

 of caustic potash, which was added in sufficient quantity to prevent any remain- 

 ing dissolved. After separation, by means of a tap funnel, from the dense alkaline 

 solution, it was again digested with sticks of the potash, until no more water was 

 removed. The general process for separating these volatile bases from non-basic 

 and other impurities, has been so often described, that it becomes unnecessary to 

 dwell upon it further. 



On distilling perfectly dry chinoline, with a thermometer in the tubulature of 

 the retort, ebullition was found to begin at about 300° F. (149°* C), although no 



* I have inserted the centigrade degrees (in round numbers), for convenience of those accustomed 

 to that scale. 



