806 SUMMARY OF CURRENT RESEARCHES RELATING TO 



siderable pressure and a screwing motion. Throwing back the ground- 

 glass screen and allowing the projecting ends of the strip to rest upon 

 the edges of the camera, as clear and distinct an image was obtained as 

 in looking through a Microscope. 



To adjust the glass to the position occupied by the plate during 

 exposure, focus with the ground-glass screen upon a printed text 

 placed at some distance from the camera, using an ordinary view lens 

 and getting the edges of the letters as sharp as possible. Then 

 throwing back the screen and being careful not to change the position 

 of the bellows, apply the eye-piece with its carrier resting against the 

 edges of the box, and screw it in or out till the sharpest and clearest 

 focus is obtained, making a mark upon the eye-piece to serve in case 

 of accident. 



When an objective is used which is not well adapted to photo- 

 graphic work, owing to the difference between the focus for vision 

 and that for actinic rays, the eye-piece can be so adjusted, by experi- 

 ment, that when the image is sharp as seen in the eye-piece the 

 actinic rays will be focused on the plate. 



Photo-Micrography in Legal Cases.*— Dr. W. T. Belfield points 

 out that among the numerous applications of photography, none is 

 more satisfactory to the operator than photography with the Micro- 

 scope in legal cases, it being indeed the only way for conveying to 

 judge or jury absolutely accurate and faithful conceptions of the 

 microscopic appearances upon which the expert microscopist bases his 

 evidence. 



It is naturally and notoriously difficult to present technical 

 evidence clearly to a jury ; and this difficulty arises not necessarily 

 from any lack of intelligence on the part of the jury, but simply from 

 their lack of technical knowledge of the subject in question. The 

 difficulty is especially great in presenting facts obtained through the 

 Microscope. The actual exhibition of such objects as blood-corpuscles 

 in court cannot be satisfactorily accomplished, and while drawings 

 made with the Microscope are admissible as means of general illustra- 

 tion, they are totally inadmissible as representations of absolute 

 accuracy and fidelity to nature. 



The photograph is the only method which we at present possess 

 whereby accurate and faithful representations of microscopic objects 

 can be presented to individuals who are not familiar with the instru- 

 ment. 



The author then relates a case coming within his own experience 

 of the application of photo-micrography to the determination of a 

 legal question. 



" I was induced to submit hairpins to microscopic examination 

 some months ago under the following circumstances : — In the pocket 

 of Zura Burns, found murdered at Lincoln last October, was found a 

 single hairpin ; in the buggy of O. A. Carpenter, suspected of having 

 perpetrated the murder, were found two pins, one of which appeared 

 to be the exact counterpart of the pin found in the girl's pocket. 



* ' Photography ' (Chicago), i. (1884) pp. 54-9 (7 figs.). 



