Transparent Bodies by the Action of Magnetism. 417 



some physicists have imagined, they are not greater according 

 as the diamagnctism of the bodies increases. Although I have 

 not made any direct experiments on this point, yet it will be 

 seen in the sequel, that, in the prosecution of my researches, the 

 question has been solved indirectly and in the negative. 



In the preceding Table several series of numbers are given, 

 belonging to different solutions of the same salt in different 

 states of concentration. This gives rise to the following im- 

 portant observation. If we suppose that in a solution the mole- 

 cules of the water and those of the salt exert their actions upon 

 the polarized light independently of one another, and if, in 

 accordance with this hypothesis, and taking account of the com- 

 position and density of the solution, we calculate the action 

 exerted by the dissolved salt, wx find, for the different solutions 

 of the same salt, numbers proportional to the quantity of salt 

 contained in one unit volume of the solution. The above hypo- 

 thesis is accordingly supported by experiment, and the salt dis- 

 solved in water behaves like sugar dissolved in an active liquid. 

 The constant quotient obtained by dividing the rotation due to 

 the salt by the quantity of salt contained in a unit volume of 

 the solution (density of salt in solution), may receive the name 

 " molecular maf/ncto-rotary •power P In the following Table I 

 have arranged the results given by solutions of protochloride of 

 tin, chloride of zinc, and chloride of ammonium. 



Table II. 



No similar calculations were made with the two solutions of 

 chloride of calcium and the two of carbonate of potash which I 

 examined, because the inagneto-rotary powers of three of these 

 solutions differed so slightly from that of M'ater, that it was im- 

 possible to make use of them to calculate the exact values of the 

 molecular jwwcrs. 



