^^ Dr. Axxdtvson on the Products of the 



It is clear, from these analyses, that the salt obtained is that 

 of the base of which the analysis is given above ; but it is equally 

 evident, fi*om the presence of small quantities of picoline, that 

 the base itself was not obtained in a state of absolute purity, 

 notwithstanding the close approximation of the experimental 

 results with those required by theory. I have been struck 

 throughout the whole course of the investigation by the fact, 

 that when the fraction corresponding to the boiling-point of any 

 particular base has been analysed, results very nearly correct 

 were obtained, even when the substance was very far from being 

 pure. I found, for instance, in the earlier part of the investiga- 

 tion, that the fraction boiling between 270 and 280°, after one 

 or two rectifications, gives precisely the results obtained from 

 pure picoline, although on further rectification the fluid will 

 begin to boil about 250°, and a small portion will still remain in 

 the retort when the thermometer has risen to 300°. It is, how- 

 ever, readily intelligible, that this should be the case when we 

 have to deal with a series of homologous bases, in which the 

 per-centage of carbon goes on increasing as the boiling-point 

 rises, so that, as in this particular case, we have the excess of 

 carbon in the less volatile base exactly counterbalancing the de- 

 ficiency in the more volatile. Thus lutidine, containing 78*5 

 per cent, of carbon, and pyridine only 75*9, and each successive 

 rectification removing equal quantities of the more and less vola- 

 tile substances of which the boiling-points are equidistant from 

 that of the intermediate member of the series, must always leave 

 a substance in which the quantities of the two impurities must 

 be exactly sufficient to counterbalance the error which each will 

 occasion. 



Hydrargo-chlonde of Lutidine. — I directed my attention to 

 this compound, which is sparingly soluble and crystallizable, in 

 hopes that it might be adapted to the purification of the base 

 itself. I soon, however, abandoned it, as it turned out that it 

 was not possible, in repeating its preparation, to obtain inva- 

 riably the same substance, each base appearing, like aniline, to 

 form different compounds with corrosive sublimate. When a 

 solution of corrosive sublimate in alcohol is added to an alcoholic 

 solution of lutidine, a curdy white precipitate falls immediately, 

 unless the solutions be highly dilute, in which case it is slowly 

 deposited in gi-oups of radiated crystals. This salt dissolves in 

 boiling water, with partial decomposition ; it is still more soluble 

 in spirit, and is deposited unchanged as the solution cools. The 

 following analysis ^i^^onds exactly with the formula 2Hg 

 Cl + C^^H^N. ,,ri -nlTt. 



7-850 grs. dried in vacuo gave 6*373 of carbonic acid, and 

 1*905 water. 



