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ARTICLE XVI. 
On Vision, and the Action of Light on all Bodies. By Professor 
Lupwic Moser of Kénigsberg*. 
[From Poggendorfi’s Annalen, vol. lvi. p. 177, No. 6, 1842 +.] 
AT the present time, when so many researches are made upon 
the action of light on the surfaces of certain bodies,—an influence 
which has been denominated chemical, but which can hardly be 
called so much longer,—the question might be asked, is the in- 
fluence of light on the retina of the same nature? Is the optic 
nerve the conductor of the oscillations of light, or does it convey 
the sensation of its material action to the central organ? I be- 
lieve there are many phenomena of vision which cannot be well 
brought into accordance with the first supposition, and which 
become quite comprehensible if we allow of a material influence. 
To mention only one instance, I would direct attention to the 
influence which Time exerts in the process of vision, inasmuch 
as external objects are not perceived instantaneously, their colour 
depending upon the length of time spent in observing them, 
and finally, the objects seen do not vanish with them, but re- 
main present to the eye for a greater or less space of time. In 
the following paper I shall attempt to carry out, as far as possi- 
ble, the analogy in the action of light on the retina and on other 
substances which are at present being studied, without, however, 
going one step further than I am justified in doing by my nu- 
merous researches. I am well aware that philosophers might 
not be very favourably inclined towards the subject of which I 
am about to speak, since a strong prejudice exists against the 
assumption of light producing material changes in the retina, 
even though they were so very inconsiderable, as I hope to be 
able to prove they are. Such being the case, the subject re- 
quires the greatest care; but this cannot induce me to keep back 
a view which, after mature consideration, appears to me to be 
well-founded. 
* Translated by Henry Croft, Esq., Professor of Chemistry in the University 
of Toronto in Canada. 
{+ The exact date of this paper cannot be given ; it was probably published 
about the end of June, as the dnnalen generally appear about the end of the 
month, for which they are intended.— Eb. ] 
