SCIENCE-GOSS/I'. 



135 



as ilicsc can l.i.' i'i\(lii>graphc<l in ii)> mnny s.'cunds, and 

 llif whiilc licidy in a few niinuU's. 



I'f'iljably some nf mir leaders have lieen alile In 

 keep pace «ilh the advances made in \-Kay work. 

 There are others, however, whu have had iheir 

 allenlinn called in diHTerent directions, liiit who wish 

 to Ik.' nct|uainled with siiHicient data and infoniiation 

 to enalile iheni to do some practical work upon the 

 suliject. .\lthout;h these articles are written more 

 particularly for the latter, it is hoped they will prove 

 fnteresliny to the former, inasmuch as some of the 

 later improvements will he touched upon. 



It is proposed therefore to first give a short 

 summary of the work from 1S95, then to discuss the 

 more service:\l)le apparatus and arrangements of such 

 for different rei|iiirenients, and also to instance some 

 of the results oliiainud wlili iniprovcd and enlar{,'ed 

 apparatus. 



Kull credit is liheially given to Professor Riintgen 

 for his wonderful discovery of the properties of the 

 invisil)le rays emanating from his vacuum tulie, when 



depending up<iii the pro.\iniity of the part in i|ueslioii 

 to the skin, and therefore to the photographic plate. 

 Not only has the l)o<ly lieen thus examined in parts, 

 but life-size radiographs of the adult frame have been 

 obtained at one exposure, thus showing the remarkable 

 help given to the medical profession. It is in the 

 treatment of fractures and dislocations, and in the 

 detection and removal of foreign bodies such as 

 bullets, or of unnatural growths and deposits, like 

 calculi, that the most useful work has been, and is now 

 lieing, done. 



At first difficulty was experienccil in locating the 

 exact position in the body of the abnormal substance. 

 An ingenious instrument wa.s, however, designed bv 

 Dr. .Mackenzie Davidson, through the use of which, 

 by taking two radiographs with the .\-Ray tube in 

 ililfereni positions, the exact spot was found. Recently 

 a. very simple and most compact instrument has been 

 brought forward for the same purpose and called a 

 " punctogiaph.'' It consists (Kig. J) of a light but rigid 

 frame of ebonite, with a brxss washer M at one end. 



!■ III. .1." I'r.NCTOiiUAni . 

 /•'or arriving at the exact fiositioft, in t/ir body^ o/a hiilt't or ot/lrr/orfign stit'Sttincr. 



the latter was co\ered with an npat|ue substance, lie 

 found they were capable of exciting fluorescence in a 

 specially prepared paper lying near the tube, and al.so 

 of exerting a selective action upon photographic 

 plates. The preceding work of Crookes, Hertz, 

 Lenard and others upon electrical discharge and 

 radiation in vacuo should not, howe\er, be forgotten. 

 These same invisible rays were probably generated in 

 Crookes' classical vacuum tube experiments some 

 twenty or thirty years ago, and were lying latent in 

 the work of later experimenters. It was left to 

 Riintgen to capture them as it were, to make the 

 ■discovery that has brought his name before all the 

 world, and to give us an invaluable method of exaniina- 

 tii>n of bodies, both in the medical and physical 

 worlds. 



There are very few hospitals at the present day 

 which are not eijuipped with an .\-Ray department, 

 where cases can be taken and inmiediately diagnosed. 

 Two metho<ls of examination are available to the 

 surgeon ; firstly the radioscopic, that is the observa- 

 tion of the \- Ray shadow produced upon a fluorescent 

 screen by a body placed between it and the source of 

 the rays; secondly, the radiographic method which 

 resolves itself into nothing more than exposing a 

 photographic plate to the rays, the body being placed 

 in contact with the film of the plate and liciween the 

 latter and the .K- Ray .source. Both methods are exten- 

 sively used in practice as occasion demands. The 

 radiographic process has the advantage of producing 

 a permanent record of the subject in question. 



Every part of the human body has I loen successfully 

 dealt with radiographically, the amount of di-tinilion 



Running the length of the frame is a spring and 

 trigger arrangement R G such that, when the latter 

 is drawn, a small pencil is relea.sed and flies into the 

 centre of the br.iss washer, thus making a mark upon 

 whatever substance with which the instrument is in con- 

 tact. Two punctographs are necessary for an observa- 

 tion. .Suppose the thorax is being examined for a bullet ; 

 the patient is pKiced in position between the X-Ray 

 lube and a fluorescent screen, the punclograph.s are 

 placed in contact with the skin, one in front and the 

 other at the back of the chest, and arranged so that 

 the two holes in the brass washers, together with the 

 bullet, are in one straight line. The triggers are then 

 drawn, and the two pencil marks are made upon the 

 patient. Exactly the same process is gone through 

 with the punctographs in different positions, and 

 again two marks made. Krom these four marks 

 and their distances apart on the chest and back, it is 

 only a matter of the geoinelry of similar triangles, to 

 calculate the exact position of the bullet. The 

 punclograph is only about twelve inches long, and is 

 easily handled. 



Two practical sources for the production of .\- Rays 

 are available and are used — the Induction Coil and 

 the Wimshursl Klectrical Machine. By far the 

 greater work is being done with the former, although, 

 when the advantages and disadvantages of the two 

 methods under difterent conditions are considered, it 

 is surprising that the Wimshurst machine is not more 

 used, Kspeciallv would it be more advantageous to 

 the army surgeon or to workers in some parts of 

 India, China, &c,, where there are no electrical 

 generating stations, and where primary batteries are 



