PHOTOGRAPHIC OUTFIT 15 



reduce the bromide of silver to metallic silver in 

 other words, the developing agent causes the image 

 to appear. The image will, of course, appear re- 

 versed; that is to say, the objects which in nature 

 are black will show transparent, while the white ob- 

 jects become black. This is caused by the action of 

 light on the sensitive film: white, reflecting more 

 light, acts energetically on the film, while black, re- 

 flecting as it does no light or scarcely any, has cor- 

 respondingly little effect on the film. 



Now, of the important considerations in making 

 a negative, the first is to have it correctly exposed; 

 the next is to use the developer best suited to the 

 subject and the plate. There are so many developers 

 to-day that it is no wonder the beginner becomes 

 confused in trying to select " the best." It is not so 

 very long ago (up to about 1880, I think) that pyro 

 and ferrous oxalate were the only two ; then came 

 hydroquinone, which in turn was followed by the 

 vast number which we see to-day. Some of them 

 are good, but as a rule they are too violent. Pyro 

 still holds its own with those who do not object to 

 its finger-staining properties. With each brand of 

 plates the makers give the formula best suited to the 

 plate, and we cannot do much better than follow 

 their directions. For my own part, I prefer pyro to 

 all others for general work. Occasionally, for a very 

 much under-exposed plate, edinol or metol or some 



