156 PKOGRESS IN KADIOGRAPHY. 



Or, in another instance, a victim of despair has turned his weapon 

 on his own heart. The probe moves cautiously, for its direction 

 seems to indicate that the attempt was successful. But no ; the ball 

 has turned aside ; the probe encounters some unbroken tissues not far 

 from the surface. Here again the radiograph is necessary. 



The direction of entry of a projectile is too frequently but little 

 indication of its direction in the body. A ball aimed at the heart 

 may be found in the intestines or the lower back, or a bullet entering 

 the right temple is lodged on the left, after having rebounded into 

 the interior of the cranial cavity. 



When an undesirable object has been swallowed, it is, of course, not 

 very difhcult to foretell the road it will travel, but to know the posi- 

 tion of these capricious tourists at any given moment is difficult. 

 Many of them halt en route; and these are just the ones it is necessary 

 to look after. The radiograph must be called into service. 



The treacherous needle, entire or broken, enters the muscular tis- 

 sues. You think it can not be far from the surface. It is a great mis- 

 take. Try if you will to extract it; the needle travels. Let us exam- 

 ine this strange game of hide and seek; whether broken or not the 

 needle has at one end a very sharp point and at the other a blunter 

 extremity which penetrates with more difficulty. If it be a broken 

 end, it will not penetrate at all save in the softest tissues. There- 

 fore each movement, each muscular contraction, drives the sharp 

 point deeper and deeper, and as its blunt end will permit no retreat 

 the needle advances, traveling ceaselessly in most unexpected direc- 

 tions. To remove it, a most exact localization is necessary, since 

 a needle is a small object to begin with, and when embedded in a 

 heavy muscle a surgeon has the utmost difficulty in discovering it 

 with ordinary instruments. 



The extraction of any foreign body calls likewise for a most pre- 

 cise localization; only the exact knoAvledge of the whereabouts of such 

 a body will reduce the operative interference to a minimum. 



The method of locating projectiles lodged in the skull, devised in 

 1897 by Monsieur Contremoulins, has solved with a marvellous 

 degree of precision the question of exact localization. The princi- 

 ])les of this method are explained by the inventor in an article pub- 

 lished by the Revue Internationale d'Electrotherapie et de Radio- 

 graphic (pi. VIII, fig. 1) : 



Given a head containing a projectile " x," we begin our determination of the 

 exact position of the bullet with reference to the skull. On any three points 

 of the face we apply the extremities of the three branches of a compass (a, ft, c), 

 which are attached to o', h', e'. On the right of the head is the photographic 

 plate E E' ; on the left the two Crookes tubes L U, held constantly in the same 

 relation to the head and the plate. 



Now, if we operate successively the two tubes we will have the shadow of 

 the projectile "x" on two different points on the plate E E'. (These points 



