86 ELEMENTARY PHOTO-MICROGRAPHY. 



corner and suspended from a line until dry. Print 

 ing frames should have open ends to enable the 

 paper to be raised for examination with ease when 

 the half-back is folded over on its hinge. Some 

 cheap frames have a deep recess, into which the 

 negative and paper drop as into a box, making it 

 extremely difficult to inspect the process of print- 

 ing without creasing the paper in the endeavour to 

 raise it. A mask with an opening of a suitable 

 size and shape placed between the negative and the 

 paper will give a neat finish to the print. 



Bromide paper is the quickest for microscopic 

 work, and can be done by gaslight. It gives a 

 contrast of velvety black and white, but the picture 

 is not visible after exposure until developed. More 

 uniform results may be obtained from artificial 

 light than from daylight, if several prints are to be 

 taken from one negative, because the correct 

 exposure, having once been ascertained, can be 

 repeated. 



The Velox carbon matt is especially suitable for 

 the purpose, being a slow paper capable of de- 

 velopment without a dark room lamp and in fairly 

 full gaslight. This is a great relief to the eyes, 

 avoiding, as it does, the fatigue caused by frequent 

 alternations of bright light for exposure and com- 

 parative darkness for development, when quick 

 papers are used. In any case, all the negatives to 

 be printed from should be put in separate frames 



