Rotatory Polarization of Liquids. 401 



Water. 

 17° 30 8° 20 9° 10 



17 25 



8 15 



9 10 



17 25 



8 20 



9 5 



17 25 



8 25 



9 



17 25 



8 25 



9 



17 25 



8 20 



9 5 



17 25 



8 20 



9 5 



Mean rotation ..95 



Taking the ratio of 7° 58' to 9° 5', we obtain from this series 

 the number 0*877 to represent the specific magneto-rotatory 

 power of alcohol. The mode of operation was the same for the 

 series which gave the numbers 0*876, 0'873, 0-879, 0*875. A 

 difference of 10' between the observations of one series was quite 

 exceptional, and a greater difference extremely rare. 





Sulphide of Carbon. 





Three series of experiments gave : — 





Sulphide. 



Water. 



Ratio. 



32 10 



10 20 



3-130 



31 40 



10 



3*116 



29 30 



9 20 



3*160 



The experiments of the third series were made with sulphide 

 of carbon prepared at Paris, and probably a little purer than that 

 with which I operated at first. I think, then, that we must take 

 the mean of the first two series, viz. 3*123, for the coefficient of 

 the specific magneto-rotatory polarization of the first sample of 

 sulphide of carbon I used, and 3*16 for that of the Paris sample 

 (sp. gr. 1*270). 



I shall not transcribe here the Table of the observations which 

 compose each series, because they differ very little from one an- 

 other (scarcely from 3 to 5 minutes) ; this was owing to the ac- 

 curacy with which, with sulphide of carbon, we can seize the 

 sensible tints, which are so pronounced and consequently so 

 distinct. It is the same with the three following liquids : — 



Compounds of Ethyle. 



Oxide of Ethyle. 



Water. 



Ratio. 



/ 



8 20 



/ 



10 10 



0*838 



Bromide of Ethyle. 

 12 



10 



1-200 



Iodide of Ethyle. 

 22 2 



10 



2*233 



