Photographing Certain Natural Ol>jects. 53 



photographing; certain natural objects 

 without a camera. 



Bv W. A. KRI. LKKMA N , PlI. I). 

 Prof. I'otany, Ohio State University. 



Read at meetiiis^ of the Ohio .Academy of Sciences, Dec. 30, 1891. 



The object.s referred to in the title of this note are tho.se 

 which are transparent or transhicent, more particularly, 

 ordinary foliage leaves, and other botanical specimens, wings 

 of certain insects, fins of fishes, etc. The jirocess consists in 

 tising the object itself as the negative and printing from it in 

 the photographer's printing frame, in the ordinary manner. 



The subject was first brought to notice by V. Fayod, in 

 Ma/pii^/iia, Anno III., fasc. iii.-iv., 1889, p. 120, under the 

 title, "Note sur une nouvelle application de la Photographic 

 en botanique," accompanied with a ])late illustrating results 

 obtained. 



In the above-mentioned article, the details of the method 

 are given, which have, in general, been followed in preparing 

 the numerous specimens here placed before you. I have 

 experimented briefly, but with a variety of objects, and have 

 brought both poor and good photographs, in order that j'ou 

 might see the necessity of heeding certain precautions to 

 in.sure .success. 



The majority of foliage leaves can be used, if it is desired 

 to .secure exact reproductions of their patterns of venation. 

 Of many orders, such as Rosacese, Leguminosce, Passiflo- 

 racece, Urticacece, Gramineae, most of the leaves have veins 

 sufficiently translucent to admit of their being u.sed as neg- 

 atives, without any preliminary preparation — even previous 

 pressing and drying not being necessary. 



But in case of many leaves of the orders CompositcC, Eri- 

 caceae, Umbelli ferae, Chenopodiaceae, etc., they must be sub- 

 jected to a process of l^leaching in alcohol, followed by 

 immersion in hot ])otassic hydrate; this is to be followed by 

 thorough washing in jnire and finalh' acidulated water, and 



