PHOTOGEAPHY AND SOME OF ITS APPLICATIONS. 
BY THE EDITOR 
W E doubt if there ever was a discovery whose applications 
are more numerous^ and whose results are more uni- 
versally distributed than those of Photography. In every 
part of the civihzed worlds the photographer holds a 
certain status in society ; and although in some instances we 
find him combining the pursuit of the fine arts with an 
occupation of a less ambitious order^ he nevertheless affords 
us an example of the ubiquitous character of his calhng. The 
products of the printing-press are not now more common than 
those of the camera; for wherever there is civilization, it is 
hardly too much to say there is also photography. Nay, we 
even fancy that among people who, in every other respect, 
recall the habits of barbarians, cartes de visite are to be found. 
The photographic portrait has become one of our institutions ; 
one, in fact, of the requisite conditions of om’ existence and 
happiness ; and it is to be hoped that when Macaulay^s New 
Zealander stands upon the ruins of London Bridge, our 
indestructible photographs will afford his philosophic mind a 
clue to our former gTeatness. We have said that the results 
of photography are everywhere among us ; but we would ask 
how many there are who are familiar with the great principle 
upon which the art is based, or are acquainted with any save 
its most common-place appheations ? From a comnetion that 
comparatively few know much, either of the theory of pho- 
tography or of its appheations to the arts and sciences, wo 
have thought that a short paper on these two subjects would 
be acceptable to om* readers. 
Photography, a word derived from two Greek roots, signifies 
the process of writing with light, and is a strictly literal 
expression of the phenomena which take place when a pre- 
pared plate is exposed in a camera. The principle upon which 
the process depends is an exceedingly simple one, and is, 
briefly, that of the chemical action of sun-light upon certain 
