tors eee 
Miscellaneous Intelligence. | 279 s 
The forces of attraction given above are the constant forces of the 
magnets, which will not diminish by repeatedly and abruptly forcing 
the armature from the poles. 
4 uminizing Photogenic Glasses, (Atheneum, No. 1205.) —We 
have received from Dr. Maunoir a translation, made at the request of 
M. Scarpellini—the President of a Society having its meetings on the 
Capitol, called Romana Corrispondenza Scientifica,—of a paper pub- 
lished in the Society’s Journal by M. Luigi Ceselli, on a new process 
a 
ten for nearly two centuries. Many difficulties, however, still existed ; 
for, with the use of glass, a layer of albumen was necessary to the 
It consists of a small rectangular box, supported by three regulating 
Screws. To its base is joined a moveable plate of metal, which, being 
heated by means of a lamp of alcohol, communicates to all parts of 
box an equal degree of heat. The plate is removed when the 
water-bath is to be used instead of the lamp. The apparatus Is protected 
by a glass covering, to guard against heterogeneous bodies falling on 
the albumen. This cover is also moveable; an the box being trav 
Plates of gla The glasses are secured and their edges brought to 
bss nd by means of a tightening screw,—so t e albumen, 
when either Spreading or shrinking, may always cover the whole sur- 
face of the intermedial plate of glass. The frame ts furnished on two 
Parallel sides with a small roove to receive the albumen;—which a 
