no PHOTOGRAPHY FOR NATURALISTS. 



is it a difficult matter in natural history work to differen- 

 tiate the subject of the picture from its surroundings in 

 tone, or even in colour. All that is necessary is to coat 

 either the subject on the transparency, or the surround- 

 ings, with a solution of rubber in benzole, before 

 immersing the whole in the dye selected. The coating 

 should be a fairly substantial one, and, of course, must 

 be done with care, but there is a very little difficulty 

 in producing such a subject as a bright-green lizard 

 amidst dull-green grass, or a. dull-green lizard amidst 

 bright-green grass. 



The writer has not infrequently been consulted as 

 to a good method of making carbon transparencies. It 

 would seem that many who plunge boldly into the 

 chemical difficulties of toning P.O. P. shy at the very 

 idea of straightforward single transfer work, to say 

 nothing of carbon transparencies. It is hard to account 

 for this view, unless one is to assume that the 

 unfortunate beginner is invariably supplied by the 

 dealer with P.O. P., and tnat P.O. P. brings gold and- 

 hypo in its train. But, whatever be the real reason, 

 the hard fact remains that carbon printing is easier and 

 more economical than silver or platinum, that its results 

 are more beautiful and more permanent, and that a 

 greater variety of colour, tone, and texture in one's 

 pictures is obtainable thereby than by any other form 

 of photographic printing. Against all these advantages 

 we have to weigh the solitary disadvantage that carbon 

 tissue is only obtainable by post. 



There is no more difficulty about making a carbon 



