158 PEOGRESS IN EADIOGEAPHY. 



needle can glide to the extremity of its course its 'point touches the 

 pi'ojectile. The surgeon has then only to draw it out with his forceps. 



So precise is this method and so accurate are the instruments that 

 fragments of grains of lead have been withdrawn from the brain. 

 The localizations it achieves are rigorously exact — to the half milli- 

 meter. Altogether it renders so practicable intracranial operations 

 formerly considered impossible that one of our most celebrated sur- 

 geons acknowledged it a guiding light which renders easy and safe 

 the extraction of hidden j^rojectiles. 



By the same geometric method, somewhat simplified and with 

 modified apparatus, the exact location of foreign bodies lodged in 

 any part of the body may be discovered. Also, as will easily be seen, 

 since this method gives a precise indication of a single j^oint, it will 

 do similar service for a series of points. A projectile encounters a 

 bone and fiies into fragments, a subject has been struck by several 

 bullets, a bone is shattered into splinters; in any of these cases the 

 various-parts are located with as much precision as is the single ball. 



The number of exact localizations that the radiograph can make 

 is almost unlimited. In practical radiography this ability to take a 

 number of observations is very valuable, especially in the case of 

 malformation, for it permits an exact determination of the contour 

 of the bony matter and of faults of conformation. 



Thus metroradiography permits of exact measurements of all 

 parts of the organism which give clear images under the X rays. 

 It bears the same relation to simple radiography that quantitative 

 chemical analysis does to qualitative; that is to say, in most cases in 

 medicine, as well as in surgery, a knowledge of the nature of the case 

 is as nothing compared with a knowledge of the importance of the 

 case. 



Early in the article we noticed that in spite of the disfavor into 

 which radiography had fallen through misdirected activity, yet a 

 few serious physicists continued their work and obtained now and 

 then remarkable results, which have done much to redeem the good 

 name of radiography. A great part of the progress must be at- 

 tributed to two men, whose names should always be recognized — the 

 physicist Villars, and Chabaud, the perfecter of the Crookes tubes. 

 Among the radiographers themselves should be cited A. Londe, who, 

 during the early years, did worthy work in his photographic studies 

 at Salpetriere. His efforts were directed toward the better selection 

 and installation of radiographic material and then toward per- 

 fecting it and employing it with more method. To him we are in- 

 debted for the first practical treatise, which although superseded and 

 discredited in part, was of much interest in its day. Unfortunately, 

 however, after a few years of radiography. Monsieur Londe gave up 

 his operations at the Salpetriere. 



