Rotatory Polarization of Liquids, 



409 



sists. The researches of M. Biot have caused the admission of 

 this principle with regard to the natural rotatory power possessed 

 by certain substances. 



The numerous experiments which I made upon water and 

 upon monohydrated sulphuric acid (HO SO 3 ) have not con- 

 firmed the law which seemed to result from the preceding ob- 

 servations, as I shall show from the numbers which refer to 

 those two liquids. 



Among the series of experiments to which I submitted water 

 (all of which lead to the same conclusion), I select the follow- 

 ing — one of the last I made, and on which I bestowed particular 

 care ; it has also the advantage of comprising a greater range of 

 temperatures : — 



Distilled water. 





Temperature, 



Rotation. 







IOC. 



o / 



10 35 







21 „ 



10 30 







31 „ 



10 25 







40 „ 



10 20 







51 „ 



10 15 







60 „ 



10 10 







71 „ 



10 5 





Temperatures. 



Ratio between Ratio between 



o 



o 



the densities. 1 



;he rotations. 



10 and 21 



1-0017 



1-008 



21 



„ 31 



1-0023 



1-008 



31 



>> 40 



1-0032 



1-008 



40 



„ 51 



1-0048 



1-008 



51 



„ 60 



1-0042 



1-008 



60 



» 71 



1-0067 



1-008 



10 



„ 31 



1-0040 



1-016 



10 



,> 41 



10073 



1-022 



10 



„ 51 



1-0120 



1032 



10 



„ 60 



1-0170 



1-041 



10 



>> 71 



1-0230 



1-050 



21 



„ 60 



1-0150 



1-033 



31 



„ 60 



1-0090 



1-016 



21 



„ 71 



1-0220 



1-041 



31 



„ 71 



1-0190 



1-033 



40 



>> 71 



1-0160 



1-024 



51 



„ 71 



1-0110 



1-016 



The preceding Table 

 magneto-rotatory power 

 crease of temperature — 



Phil Mag, S.4. Vol. 



shows that, in the case of water, the 

 diminishes very regularly with the in- 

 in particular, that the ratio between the 

 40. No. 269. Bee. 1870. 2 E 



