8 DU. FARADAY’S EXPERIMENTAL RESEARCHES IN ELECTRICITY. (SERIES XIX.) 
2182. With some degree of curiosity and hope, I put gold-leaf into the magnetic 
lines, but could perceive no effect. Considering the extremely small dimensions of 
the length of the path of the polarized ray in it, any positive result was hardly to be 
expected. 
2183. In experiments with liquids, a very good method of observing the effect, is to 
inclose them in bottles from 1| to 3 or 4 inches in diameter, placing these in succes- 
sion between the magnetic poles (2150.), and bringing the analysing eye-piece so near 
to the bottle, that, by adjustment of the latter, its cylindrical form may cause a dif- 
fuse but useful image of the lamp-flame to be seen through it : the light of this image 
is easily distinguished from that which passes by irregular refraction through the 
striae and deformations of the glass, and the phenomena being looked for in this light 
are easily seen. 
2184. Water, alcohol, and ether, all show the effect ; water most, alcohol less, and 
ether the least. All the fixed oils which I have tried, including almond, castor, olive, 
poppy, linseed, sperm, elaine from hog’s lard, and distilled resin oil, produce it. The 
essential oils of turpentine, bitter almonds, spike lavender, lavender, jessamine, cloves, 
and laurel, produce it. Also naphtha of various kinds, melted spermaceti, fused sul- 
phur, chloride of sulphur, chloride of arsenic, and every other liquid substance which 
I had at hand and could submit in sufficient bulk to experiment. 
2185. Of aqueous solutions I tried 150 or more, including the soluble acids, alka- 
lies and salts, with sugar, gum, &c., the list of which would be too long to give here, 
since the great conclusion was, that the exceeding diversity of substance caused no 
exception to the general result, for all the bodies showed the property. It is indeed 
more than probable, that in all these cases the water and not the other substance 
present was the ruling matter. The same general result was obtained with alcoholic 
solutions. 
2186. Proceeding from liquids to air and gaseous bodies, I have here to state that, 
as yet, I have not been able to detect the exercise of this power in any one of the 
substances in this class. I have tried the experiment with bottles 4 inches in diameter, 
and the following gases: oxygen, nitrogen, hydrogen, nitrous oxide, olefiant gas, 
sulphurous acid, muriatic acid, carbonic acid, carbonic oxide, ammonia, sulphuretted 
hydrogen, and bromine vapour, at ordinary temperatures ; but they all gave negative 
results. With air, the trial has been carried, by another form of apparatus, to a much 
higher degree, but still ineffectually (2212.). 
218/. Before dismissing the consideration of the substances which exhibited this 
power, and in reference to those in which it was superinduced upon bodies possessing, 
naturally, rotative force (2165. 2231.), I may record, that the following are the sub- 
stances submitted to experiment: castor oil, resin oil, oil of spike lavender, of laurel, 
Canada balsam, alcoholic solution of camphor, alcoholic solution of camphor and cor- 
rosive sublimate, aqueous solutions of sugar, tartaric acid, tartrate of soda, tartrate of 
potassa and antimony, tartaric and boracic acid, and sulphate of nickel, which rotated 
to the right-hand ; copaiba balsam, which rotated the ray to the left-hand ; and two 
