14 DR. FARADAY’S EXPERIMENTAL RESEARCHES IN ELECTRICITY. (SERIES XIX.) 
Water l'O 
Alcohol less than water. 
Ether less than alcohol. 
2216. In relation to the action of magnetic and electric forces on light, I consider, 
that to know the conditions under which there is no apparent action, is to add to 
our knowledge of their mutual relations ; and will, therefore, very briefly state how 
I have lately combined these forces, obtaining no apparent result (955.). 
2217- Heavy glass, flint-glass, rock crystal, Iceland spar, oil of turpentine, and air, 
had a polarized ray passed through them ; and, at the same time, lines of electro- 
static tension (2149.) were, by means of coatings, the Leyden jar, and the electric 
machine, directed across the bodies, parallel to the polarized ray, and perpendicular 
to it, both in and across the plane of polarization ; but without any visible effect. 
The tension of a rapidly recurring, induced secondary current, was also directed upon 
the same bodies and upon water (as an electrolyte), but with the same negative 
result. 
2218. A polarized ray, powerful magnetic lines of force, and the electric lines of 
force (2149.) just described, were combined in various directions in their action on 
heavy glass (2151. 2176.), but with no other result than that due to the mutual ac- 
tion of the magnetic lines of light, already described in this paper. 
2219. A polarized ray and electric currents were combined in every possible way 
in electrolytes (951-954). The substances used were distilled water, solution of 
sugar, dilute sulphuric acid, solution of sulphate of soda, using platinum electrodes ; 
and solution of sulphate of copper, using copper electrodes : the current was sent 
along the ray, and perpendicular to it in two directions at right angles with each 
other ; the ray was made to rotate, by altering the position of the polarizing mirror, 
that the plane of polarization might be varied ; the current was used as a continuous 
current, as a rapidly intermitting current, and as a rapidly alternating double current 
of induction ; but in no case was any trace of action perceived. 
2220. Lastly, a ray of polarized light, electric currents, and magnetic lines of force, 
were directed in every possible way through dilute sulphuric acid and solution of 
sulphate of soda, but still with negative results, except in those positions where the 
phenomena already described were produced. In one arrangement, the current 
passed in the direction of radii from a central to a circumferential electrode, the con- 
trary magnetic poles being placed above and below ; and the arrangements were so 
good, that when the electric current was passing, the fluid rapidly rotated ; but a 
polarized ray sent horizontally across this arrangement was not at all affected. Also, 
when the ray was sent vertically through it, and the eye-piece moved to correspond 
to the rotation impressed upon the ray in this position by the magnetic curves alone, 
the superinduction of the passage of the electric current made not the least differ- 
ence in the effect upon the ray. 
