ty 
#. 
Correspondence of J. Nickles. 409 
In concluding, it may be remarked that the experiments which 
have been described are for the most part too obvious and fa: 
miliar to have merited such a special notice but for the peculiar 
and in some respects new interpretation which they have offered 
of many visual phenomena. Considered in this relation we are 
I think entitled to conclude from them:— 
First that the retinal impression of an object presented directly 
to either eye is accompanied by the feeling of a united vi 
act, and of itself gives no indication of the particular eye im- 
pressed ; and :— 
Second, that the reference of the impression to one eye rather 
than the other is the result of collateral suggestion, which may 
either locate the image in the eye that actually receives it, or 
may transpose it seemingly to the other, according to the partic- 
ular conditions of the observation. 
Art. XLI.— Correspondence of J. Nickles, of Nancy, France. 
plete works on circular polarization, applied to the study of chemical spe- 
cies. These researches, which he has greatly promoted, have often occu- 
pied us and daily gained more importance. Biot has given us the fol- 
lowing account of the manner in which he was led to the discovery 
of the fundamental fact which has given point to all his labors in this 
field. He says :— 
It must necessarily result from 
Some physical property, peculiar to the substance which produced it. 
A UR. SCL—SECOND SERIES, Vor. XXX, No. 90.—NOV., 1860. 
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