236 Intelligence and Miscellaneous Articles, 



Submitted to distillation, the free oxide gives rise to an oily base, 

 which I naturally expected to be lepidine ; but the experiments which 

 I have hitherto made with this substance appear to negative this 

 assumption. I have undertaken a more minute examination of the 

 compound, because, if it be different, its study will probably throw 

 some light upon the still uncertain constitution of the tertiary bases 

 of the chinoline series, which I have frequently attempted to decipher. 

 It remained now only for me to examine the mode of formation 

 of the remarkable compound the nature of which I have endeavoured 

 to clear up. With this view I have studied the action of iodide of 

 methyle and amyle upon chinoline and lepidine, large quantities of 

 which were kindly placed at my disposal by my friend Mr. David 

 Howard. The products obtained in this reaction I have not sub- 

 mitted to a minute examination, having satisfied myself that their 

 principal phases are well illustrated by the equations which I have 

 given for the formation of the substances produced by the action of 

 iodide of amyle upon lepidine. Nor have I followed out in detail the 

 complicated secondary changes, and more especially the generation 

 of the red colouring matter which is abundantly formed in these 

 reactions. I have nothing to add to the perfect description of these 

 phenomena by the distinguished discoverer of this pigment. 



In conclusion I may be allowed to express my best thanks to M. 

 Menier : without the magnificent crystals furnished by his ateliers, I 

 could not have even attempted to clear up this question. 



Though proud of her office as guide of industry, science acknow- 

 ledges without blushing that there are territories on which she cannot 

 advance without leaning on the strong arm of her powerful companion. 

 Joint labours of this kind cannot fail to seal the pledge of alliance 

 between industry and science. 



"On some new Compounds obtained by Nitrogen-substitution, 

 and new Alcohols derived therefrom." By Peter Griess, Esq. 



I' On the Differential Equations of Dynamics. A sequel to a Paper 

 on Simultaneous Differential Equations." By George Boole, F.R.S.&c. 



XXXIII. Intelligence and Miscellaneous Articles. 



ON THE ELECTRICAL CONDUCTIVITY OF THALLIUM. 

 BY M. LUCIEN DE LA RIVE. 



rilHE conductivity of thallium was measured by Wheatstone's 

 ■*• method, by comparing the resistance of a wire of this metal with 

 that of a standard of distilled mercury. The thallium used was a 

 specimen given by M. Lamy to the laboratory of rheEcole Normale. 

 It was formed into wire by being first melted, then hammered so as 

 to lengthen the bar, and finally passed through the draw plate. The 

 latter operation is rendered difficult by the feeble tenacity of the 

 thallium ; the metal must be frequently moistened, and the wire 

 carefully drawn, so as to obtain a certain degree of fineness. 

 The conductivity of a substance determined by measuring the 



