488 PROFESSOR MOSER ON LATENT LIGHT. 
Nore ON THE PRECEDING TREATISES OF M. Moser. 
The results of the researches of M. Moser were first made known in 
this country at the meeting of the British Association at Manchester 
in June last, by M. Bessel. The statement of them by Sir D. Brew- 
ster excited much interest*; it has been thought desirable therefore | 
to give a translation of the three Memoirs of M. Moser, being all that 
he has published on those properties of light of which they treat. 
Since attention was first called to these curious phenomena by Dr. 
Draper of New York in 1840+, and subsequently by M. Moser, the 
following communications on the subject have been published in the 
London, Edinburgh and Dublin Philosophical Magazine :— 
“On the Chemical Action of the Solar Spectrum on preparations of Silver.” 
By Sir J. F. W. Herscuen, Bart.—Phil. Trans. Feb. 1840, and Phil. Mag. 
S. 3. vol. xvi. p. 831. 
“ On the Action of the Rays of the Solar Spectrum on Vegetable Colours, 
and on some new Photographic Processes.” By Sir J. F. W. Herscuen, Bart. 
Communicated to the Royal Society June 15, 1842.—Phil. Trans. 1842, and 
Phil. Mag, 8. 3. vol. xxii. 
‘On certain Spectral Appearances, and on the Discovery of Latent Light.” 
By J. W. Draver, M.D., Professor of Chemistry in the University of New 
York.—Phil. Mag. p. 348, Nov. 1842. 
“ On anew Imponderable Substance, and on a Class of Chemical Rays ana- 
logous to the Rays of Dark Heat.” By Prof. Drarer.—Phil. Mag. Dec. 1842. 
“On Thermography, or the Art of Copying Engravings from Paper on 
Metallic Plates; and on the recent Discovery of Moser relative to the forma- 
tion of Images in the Dark.”’. By Mr. Rosert Hunt.—Phil. Mag. Dec. 1842. 
“On the Action of the Rays of the Solar Spectrum on the Daguerreotype 
Plate.” By Sir J. F. W. Herscner, Bart.—Phil. Mag. Feb. 1843.—See re- 
marks in this Paper on the use which Moser has made of Coloured Glasses. 
Also, a cominunication by Prof. Drarrr “ On the Rapid Detithonizing 
Power of certain Gases and Vapours, and on an instantaneous means of pro- 
ducing Spectral Appearances,” is announced for publication in the Philoso- 
phical Magazine for March. 
The following extract of a Letter from .M. Fizeau to M. Araco 
is from the Comptes Rendus, Nov. 7, 1842 :— 
On the Causes which concur in the production of the Images of Moser. 
“ Since my return I have been actively occupied with the singular phenomena 
observed by M. Moser, and I hope shortly to have the honour of laying before 
the Academy a communication on this subject. At present I shall therefore 
merely apprise you of the general results to which I have come. ‘The experi- 
ments which I have as yet made have for the most part confirmed the facts 
announced; but I must say that all have led me to take quite a different view 
of this subject from that which M. Moser does. 
‘Far from thinking that we must admit the existence of a new species of 
* See Phil. Mag. Nov. 1842, p. 409. 
+ See the following communications by Professor Draper in the London, 
Edinburgh and Dublin Philosophical Magazine :— 
1840. Feb. p. 81.—‘‘ An Account of some Experiments made in the South 
of Virginia on the Light of the Sun.” [In this letter Dr. Draper refers to 
previous communications in the Franklin Institute. ] 
1840. Sept. p. 217.—*‘ On the Process of Daguerreotype, and its application 
to taking Portraits from the Life.” 
1841. Sept. pp. 198, 199; 196, 204, 205, 206.—“‘ On some Analogies be- 
tween the Phzenomena of the Chemical Rays and those of Radiant Heat.” 
