1893.] THE MICROSCOPE. 5 



PHOTOMICROGRAPHY. 

 By F. A. Rogers. M. D., 



WORCESTER, MASS. 



Photomicrography is the art of photographing the enlarged 

 image of a microscopical object. It is the opposite of micro- 

 photography, which consists of microscopical photographs or 

 reduced images of large objects or pictures, and which have little, 

 if any, value except as curiosities. 



When the amateur landscape photographer makes up his 

 estimate of the requisites to pursue his coveted line of experi- 

 ments, he is at first met with the expense of a suitable lens, for 

 upon this depends in a great measure his success, while in photo- 

 micrography the objective, with or without the ocular, supplies 

 the lens needed. Any good objective will give a good photo- 

 micrograph if properly manipulated. 



It is best to begin with a low power, say a one-inch or three- 

 fourths-inch or even lower, and aim to secure a sharp negative 

 with good contrasts and of medium size. Be content with 

 moderate amplification and good definition. If greater amplifi- 

 cation is desired use a higher power objective rather than use a 

 higher ocular with a low-power objective. Sunlight is by far 

 the best for this purpose, yet excellent work can be done with 

 lamplight. 



Bv emploving the most simply constructed home-made appara- 

 tus and suiting the convenience of the operator, either by sun- 

 light, preferably, or by employing a single-wick kerosene burner 

 with the flame placed edgewise in the optical axis of the apparatus, 

 the principles of photomicrography can be easily illustrated and 

 beneficially employed. 



Before attempting to pursue this art, several preliminaries 

 should receive attention. A dark room is one of the needed 

 conveniences, and unless work is to be done wholly at night it 

 becomes a necessity. Some unoccupied, darkened room, ample 

 closet, or even a corner of a rough room may be suitably 

 arranged for the purpose. It should be light-tight, contain a 

 small sink and have running water if possible, but a suspended 

 pail provided with a few feet of rubber tubing with a nipper- 

 tap attached will answer the purpose of a reservoir and piping, 

 while a small tub with a shelf inserted or board across the top 

 may economize the sink. The room should contain a small 

 stand, and two or three shelves are very convenient. 



The paraphernalia needed to work with are a ruby lantern ; three 

 trays — one for developing, one for fixing, and one for toning (they 

 should be so marked that they may not get mixed) ; three 

 graduates — one eight-ounce, one two-ounce, and a minim glass ; 

 a plate lifter ; one printing frame ; Omega paper : Omega toning 



