INTRODUCTION. 
15 
into the eyes of the worker. Artificial light, on account 
of its equability, is preferable to daylight, which varies 
so much in strength and quality. 
To test the “ safety” of a lamp, lay a plate of the 
kind to be used in the place where development is to be 
performed, covering half of the plate with an opaque 
material ; leave the plate so for about five minutes, the 
lamp, of course, being lighted, and then develop with 
one of the developing solutions. If both halves of the 
plate remain clear the light is safe : but however safe 
the light, the plate should never be exposed to the light 
unnecessarily. During development it is well to cover 
the dish containing the plate with another dish or a 
piece of cardboard. 
A so-called “Matchless burner” is a great con¬ 
venience in the operating room; this is a device 
whereby an ordinary gas burner can be turned very 
low, so as not to affect a plate, without being turned 
out; the light can be turned up without loss of time, or 
relighting. 
All the appliances of a general nature required for 
the photographic part of our work are kept in stock by 
all dealers ; and these appliances are, happily, neither 
numerous nor expensive. 
In the operating room there should be a set place 
for everything used ; confusion and dust should have 
no place in the room. Care must in particular be 
taken that the “ hypo ” solution be not splashed about 
the floor or the table. Every dish and measure should 
be cleaned immediately after use ; this will be found 
economy, not waste, of time. 
