16 PRACTICAL PHOTOMICROGRAPHY. 



Many microscopic objects are so fine in substance, others so 

 intricate in structure, that the human hand is unable by any 

 device to draw them anything like accurately. 'No line visible 

 to the naked eye is too fine for photography to limn, no struc- 

 ture too intricate for the pencil of light to follow. 



By photo-micrography a vast amount of time is saved. A 

 few minutes of work may furnish us with a matrix for a 

 thousand prints, one of which, if possible at all, could not be 

 produced by hand in many hours. By photography are done 

 with moderate ease and complete accuracy many subjects which 

 by hand could not be done at all, witness moving objects, and 

 appearances rapidly changing. 



Many other claims might be made for photo-micrography, 

 but we shall cite only one more. Of all the intellectual and 

 scientific pursuits that can be named, no one possesses so great, 

 so varied fascinations as photo-micrography. There is mental 

 food and mental exercises for every one ; microscopy in all 

 its varied branches and with all its interests optics, mechanics, 

 chemistry ; and best of all, a practical, visible, permanent, use- 

 ful result an education and an educator ! 



NOTE. Since the above was written, Drs. Fraenkel and Pfeiffer, of 

 Berlin, have begun to publish a set of photo-micrographs of bacteria 

 which may be called splendid. They use daylight, apochromatic lenses 

 and orthochromatic plates. 



