CHINOLINE AND ITS HOMOLOGUES. 397 



purification adopted by him. The most satisfactory mode of explanation of the 

 differences in the properties of the coal and cinchonine series, as obtained by me, is 

 that they are in a peculiar molecular condition, analogous in some respects to the 

 phenomena known in the cases of quinine, the amylic alcohol, and many other 

 bodies, instances of which are daily becoming more numerous. Chemists are aware 

 that even variations in the density and boiling point of the same fluid, when in dif- 

 ferent states, have been observed ; and I may mention, as corroborative of this, 

 that with bases distilled the same number of times, lepidine as pure as I could 

 procure it from both sources differed in boiling point by 25° F. ; for the lowest frac- 

 tion of coal-lepidine that gave correct results on analysis distilled between 485° 

 and 495°, whereas the lowest fraction of the same base from cinchonine, boiled be- 

 tween 510° and 520° F. Another fact which seems corroborative of the supposi- 

 tion that Dr Hofmann obtained the chinoline from coal-tar in the state in which 

 I procured it from cinchonine, is found in the circumstance that the density of 

 chinoline from coal-tar was ascertained by him to be 1*081, or very near the same 

 number as in my determination of the density of the same base from cinchonine, 

 viz., 1-085. But the coal bases examined by me were lighter than this; for even 

 the lepidine from the the last source had a density of only 1-072 at 60° F., being 

 actually lighter than the homologue, one step below from cinchonine. 



I have observed with the pyridine series, as obtained from bone-oil, coal- 

 naphtha, and bituminous shale, that considerable differences are found in their 

 power of forming crystalline salts, and it is, therefore, most probable that the 

 same distinctions exist between them that are met with in the case of the bases 

 from coal and cinchonine. I trust eventually to be able to elucidate some of 

 these points, by subjecting chinoline from both the above substances to the action 

 of polarized light. 



The lepidine platinum salt, from cinchonine, precipitates at once in a pulveru- 

 lent state ; but from coal it is for a few seconds soft and resinous, but soon be- 

 comes hard and crystalline. The following are my analyses of it from the latter 

 source : — 



( 9*216 grains crystallized platinochloride of lepidine from fraction boiling 485°-95° 



M 



11-652 ... carbonic acid, and 



14th rectification, dried at 212°, gave 



III. 



^ 2-466 ... water. 

 TT f 5-954 ... platinochloride lepidine from fraction 48 5°-9 5°, gave 

 ' \ 1-673 .. platinum. 



platinochloride lepidine from fraction 495°-505°, 14th rectification, gave 



carbonic acid, and 



water. 



platinochloride lepidine, same as last, gave 

 platinum. 



platinum salt, 485°-95° crystallized, gave 

 platinum. 



VOL. XXI. PART III. 5 P 



