306 Mr. Williams — Researches on Isomeric Alkaloids. [June 16, 



ing-poiat. It may be inferred from this that the boiling-point of /3-luti- 

 dine has not been estimated above the truth, because if the fraction had 

 been taken too high, the vapour-density would have erred considerably in 

 excess. This will be the more evident if we consider that a determination 

 of a vapour-density by the method of Dumas is, in fact, a process of frac- 

 tional distillation ; and if any base of higher formula had been mixed with 

 it, it would have remained in the balloon, and increased the density to an 

 extent proportional to the amount of imparity. The experiment, therefore, 

 tends to show that the true boiling-point of lutidine is, if anything, a little 

 below 154°, and that of /3-lutidine is about 165°, inasmuch as the error is 

 not greater than that usually observed with the purest substances obtained 

 by fractional distillation. 



The author, after stating that the specimen of lutidine employed in the 

 investigation vv^as prepared by Anderson himself, shows that lutidine retains 

 its colourless state after rectification longer than /3-lutidine. 



Comparative Study of the Platinum-Salts of Lutidine and [^-Lutidine. 



The author states that before entering on the comparative examination 

 of the bases, he determined their composition by converting them into 

 platinum-salts. They both gave numbers so closely agreeing with those 

 demanded by calculation from their formulae, that it was evident that the 

 specimens used were pure. 



He then proceeded to ascertain whether any differences existed in their 

 capability of yielding crystalline platinum-salts. 



I. ^-Lutidine. — A solution of hydrochlorate of the base was mixed with 

 a solution of dichloride of platinum, the exact strength of the solutions 

 being known. The mixture solidified instantly to a mass of crystalline 

 plates. After 48 hours' repose their weight was determined and found to 

 be 1*780 gramme. 



II. Lutidine. — A precisely similar experiment was made with lutidine. 

 No signs of crystaUization appeared for 15 minutes. A few crystalline 

 points then began to form. After 48 hours the weight of the crystals 

 which had then formed was found to be 0*816 gramme. 



The experiment was then repeated, a known weight of water being added 

 to each solution. 



III. ^-Lutidine. — A large quantity of crystalline plates was deposited 

 instantly. In five minutes the whole ^had solidified. After 48 hours' re- 

 pose, the weight of the crystals was found to be 1*66 gramme. 



IV. Lutidine. — No crystals appeared for 35 minutes. After 48 hours 

 the weight of crystals formed was found to be 0*83 gramme. 



The experiments III. and IV., like I. and II., show that j3-lutidiue, 

 under exactly the same conditions, gives twice as much salt as the Dippel 

 base. 



As, according to Dr. Anderson, the presence of hydrochloric acid in 

 excess greatly retards the formation of the lutidine salt, the author made 



