394 Intelligence and Miscellaneous Articles. 
3 Monocerolis, between Rigel and « Leporis, nearly in the direction of 
8 Eridani: and Sir John Herschel obtained a view of the head, which 
he concluded to be near one of the stars of p Eridani; its appear- 
ance being that of a star of the fifth magnitude, but dim, and having 
no sharp nucleus. The star 63 Hridani was in the tail, a trifle north 
of its axis. No bifurcation could be perceived; the axis being 
throughout rather the brightest part. Its direction is very nearly 
parallel to the equator, though a slight curvature may be suspected, 
the convexity being northward. By comparing the observed place of 
the tail on the 24th with that noticed by Mr. Cooper on the 14th (when 
it passed over y Eridani),it appears to have advanced northward about 
four degrees in the interval of ten days. This direction and quantity 
of motion was confirmed by an observation on the 25th, when 63 
Eridani was found to be still iz the tail, but near its southern border. 
The almost constant presence of cloud or haze near the south- 
western horizon has greatly interfered with observations of the nu- 
cleus; but it is to be hoped that ere long it will be satisfactorily 
observed with the large fixed instruments at some of our principal 
observatories. 
RESEARCHES ON THE FORMATION OF MOSER’S IMAGES. 
Extract from a Letter from M. Fizeau to M. Arago. Comptes Rendus, 
Feb. 13, 1843, p. 397. 
*«In a letter which I had the honour of addressing to you, 
and which you were pleased to communicate to the Academy of 
Sciences on the 7th of November (see Scientific Memoirs, vol. ii. 
p. 488), I mentioned some experiments relative to the phenomena 
observed by M. Moser*, namely, the formation of the images that 
make their appearance on a polished surface when bodies are placed 
very close thereto. These experiments had led me to consider these 
novel facts, contrary to the opinion of Moser, as foreign to every 
species of radiation, and to ascribe them to the well proved existence 
of fatty and volatile matters which soil the surface of most bodies. 
** Not having completed the inquiry which I shall have the honour 
to present to the Academy on this subject, I am desirous of ac- 
quainting you with the principal facts on which the explanation which 
I propose is based. 
«|. The property of forming images on a polished surface is not 
permanent in bodies; but if with the same body we seek to obtain a 
great number of images successively its power is seen to grow weak 
by degrees, and becomes almost nothing after a certain number of 
impressions, a number which varies with the nature and especially 
with the texture of the bodies; compact bodies such as the metals 
rapidly losing this property, porous bodies on the contrary retaining 
it in a remarkable manner. 
«2, When the property of producing images is lost or weakened 
in a body, it can be instantaneously restored to it by passing the 
fingers along its surface, or by rubbing this surface with the hairs 
* See an account of these discoveries in (vol. iii.) Part XI. of Scientific 
Memoirs in the three treatises of Moser On the Action of Light on Bodies, 
On Invisible Light, and On the Power which Light possesses of becoming 
Latent, 
