WITH THE MICROSCOPE. 



2/5 



the print pressed equally all over. Some use thin Scotch glue instead 

 of mucilage. 



When the cards are nearly dry, they should be passed through 

 the rolling press. 



Many useful hints on various subjects connected with micro- 

 scopical photography will be found in the Photographic News 

 Almanack and the British Journal Photographic Almanack for the 

 last few years. 



353. Magnesium Light. Those who wish to devote their evenings 

 to the production of negatives of microscopic objects may employ 

 the electric, oxy-hydrogen, or magnesium light. Mr. Highley has 

 introduced two forms of Electric Regulator, one being adjusted by 

 the hand but with provisions for keeping the point of light central ; 

 the other is self-adjusting and is excessively sensitive. A third form 

 is cheaper than the foreign instruments hitherto employed. The 

 oxy-hydrogen lamp is the same as that described under the Magic 

 Lantern apparatus. 



Dr. Henry Morton, of Philadelphia, has likewise made a con- 

 siderable improvement in magnesium lamps, by adapting a metal 

 chimney, wide enough to prevent the flame from touching the sides ; 

 the bottom is closed up either by metal or by being placed in a dish 

 of water. Opposite the ignited wire is a round hole in the side 

 of the chimney through which the air enters, and striking against 

 the flame increases its brightness and intensity in a very marked 

 manner, thus effecting equal illumination at a much less expense. 

 Following up this idea for ordinary use, Dr. Maddox has con- 



^Hi 



structed an apparatus for using short lengths of wire in photo- 

 micrography, and which will be best understood by a reference to 

 A stout tin tube, about 8 inches high and i^ inch 



the figure. 



T 2 



