187 



was also found present in that portion of the mixed t^rs which dis- 

 tilled above 355°, and was distinguished by its reaction with chloride 

 of lime. 



The author also mentions the existence of several other bases, the 

 constitution and properties of which will be described in the second 

 part of his researches. 



3. Note respecting the Refractive and Dispersive Power of 

 Chloroform. By Professor Forbes. 



From an experiment made in very cloudy weather, and therefore 

 rather unfavourable light, I determined the following indices of re- 

 fraction for pure chloroform, prepared by Dr George Wilson, of sp. 

 gr. 1-4966. 



The measure of the refracting angle of the prism was 39" 41'. 

 References were made to the principal lines of the spectrum, as 

 below : the temperature of the fluid was probably 54'^. 



Extreme red, 



B (in the red), 



D (in the orange-yellow), 



b (in the green), 



F (in the blue), 



H (in the violet, being the least refrangible of 



the two groups so designated), 

 Extreme violet. 



Hence the refractive index is by no means remarkably great, 

 being nearly that of wax, spermaceti, and several of the essential 

 oils. 



The dispersive power, or is equal to "045, which agam agrees 



nearly with that of the essential oils. The high specific gravity of 

 the body appears to have no marked influence in increasing its action 

 on light. 



The following Gentlemen were duly elected Ordinary 

 Fellows : — 



Dr Patkicx Newbigoing. 

 W. Swan, Esq. 



