416 Prof. A. De la Rive's Researches on the Magnetic 



The liquids gave the following results, each deduced from five 

 series of experiments* : — 



Acetate of Amyle. 



Acetate. Water. 



8 40 

 8 26 

 8 40 

 8 54 

 8 50 



9 35 

 9 20 

 9 36 

 9 50 

 9 45 



Mean 



Ratio. 



0-904 

 0-902 

 0-903 

 0905 

 0-906 



0-904 



Valerate of Ethyle. 

 Valerate. Water. 



20 

 5 

 13 

 30 

 12 



9 30 

 9 10 

 9 20 

 9 45 

 9 23 



Mean 



Ratio. 



0-877 

 0-881 

 0-880 

 0-879 

 0-877 



0-879 



Butyrate oflsopropyle. 



Butyrate. Water. 



Ratio. 



8 20 



9 40 



0-862 



8 5 



9 20 



0-866 



8 30 



9 50 



0-864 



8 12 



9 30 



0-863 



8 23 



9 40 



0865 





Mean . 



. 0-864 



I have excluded one of the series of experiments, which gave 

 results, for the three liquids, very different from those furnished 

 by the five series from which the above Tables were constructed ; 

 yet the numbers found agreed very well, as to their ratios, with 

 those resulting from the respective means of the three Tables : 

 they were, for acetate of amyle 0-893, for valerate of ethyle 0*858, 

 and for butyrate of isopropyle 0*853. I can only attribute this 

 difference (which only occurred once) to the very high tempera- 

 ture (more than 30°) at which these last-mentioned experiments 

 were made. But if this series be introduced into the three Tables, 

 the mean becomes for the acetate 0'902 instead of 0*904, for the 

 valerate 0*877 instead of 0*879, and for the butyrate 0862 

 instead of 0-864 : these numbers would then express the specific 

 magneto-rotatory powers of the three liquids respectively. I 

 prefer, however, to adopt the former ones. 



In either case it follows from the preceding experiments that 

 the three isomers have sensibly different magneto-rotatory 

 powers — the butyrate a lower power than the valerate, and the 

 valerate a considerably lower one than the acetate, as I had 



* I ought to remark that I had not sufficient liquid to give the columns 

 a length of 10 centims. Those of acetate of amyle and butyrate of iso- 

 propyle were each 6 centims., and that of valerate of ethyle only h\ 

 centims. long. Of course the water column was always of the same length 

 as that of the liquid with which it was compared. 



