56 



THE MUSEUM. 



different parts of the negative and 

 hence the image thereon, being caus- 

 ed by difference in amount of hght 

 striking those points. 



The Rontgen rays (x-rays) like or- 

 dinary Hght will decompose salts of 

 silver. If then in the above e.xperi- 

 ment the florescent screen be replaced 

 by a photographic dry-plate and the 

 shadow of a hand or other object be 

 retained there, it is obvious that where 

 the shadow of the bones strikes this 

 plate no change in the silver com- 

 pound will take place. Where the 

 rays strike the flesh, the shadow is 

 less distinct and a slight change takes 

 place on the plate. Entirely sur- 

 rounding the object, where the rays 

 strike the plate practically unobstruct- 

 ed a more thorough decomposition 

 takes place and the negative after be- 

 ing developed is here more dense. 



Prints, or positives are made from 

 this negative as from all others by 

 placing the sensitized paper in inti- 

 mate contact with the negative and 

 exposing to sunlight. These parts of 

 course have to be toned and mounted 

 the same as other photographs. 

 Photos made in this way show bones, 

 metallic objects, etc., much more 

 clearly than they are shown upon the 

 florescent screen. As the x-rays pen- 

 etrate readily wood, rubber or leather 

 the plate holder of an ordinary camera 

 is used to hold the plate in position 

 and the slide is not withdrawn from 

 the holder at all. This allows of a 

 photograph being taken in ordinary 

 daylight without danger of fogging 

 from light. 



One of Our most interesting experi- 

 ments was as follows: An ordinary 

 Anthony plate containing an unexpos- 

 ed dry-plate was laid upon our operat- 

 ing table and upon this was placed a 

 large frog {Rana maculata) in life-like 

 position. The specimen in question 

 was an alcoholic one, as the living ar- 

 ticle could not be induced to hold still 

 for much more than the thousandth 

 part of a second — and that was not 

 long enough for our purpose. The 



bulb of the Crookes tube was now sus- 

 pended a few inches above the frog 

 and the current allowed to pass for 

 about seventy-five seconds. The 

 plate was then developed and the re- 

 sult was a negative showing every 

 bone in its natural position. All could 

 be readily distinguished except the 

 finer bones of the skull where some 

 were superimposed upon others. A 

 body in the abdomen appeared to be 

 opaque to the rays and upon the fin- 

 islicd photo appeared as a dark spot 

 — it was presumably the liver but this 

 has not yet been demonstrated. 



Photos of other objects such as a 

 pocketbook containing coins and keys, 

 coins placed in books, deformed and 

 broken finger bones, enlarged joints, 

 etc., were made in the same manner 

 and with equal success. A popular 

 photo and a fine one is that of the 

 bones inthe living human hand. 



In locating broken or displaced 

 bones this system is invaluable to sur- 

 geons and physicians and has been 

 much used for such purposes. Upon 

 one occasion during the past summer 

 some of my fellow-workers in a few 

 minutes' time located accurately a 22 

 cal. bullet in the wrist of a young man 

 and which the doctors were unable to 

 locate after continuous probing. 



As the apparatus used is very deli- 

 cate and expensive the average ama- 

 teur photographer is not supplied 

 therewith, but it is sincerely hoped 

 that the day will soon arrive when this 

 wonderful discovery can be turned to 

 many practical uses by the masses. 

 As it is every scientific student as well 

 as everyone interested in modern pro- 

 gress cannot but be interested in ex- 

 periments along these lines. 



Human Relics in the Drift of Ohio 



The above is the title of an article 

 presented by Dr. E. W. Claypole of 

 Akron, O. at the A. A. A. S., at Buf- 

 falo, N. Y. , August, 1896 and also 

 published in the November number of 

 the American Geologist, Minneapolis, 

 Minn. The find, a stone axe, seems 



