The age-herald., 1900-12-23
MODERN BULLET WOUNDS.
An Investigation on the Action of Pres ent-Day Rifle Bullets In the Body.
From the New York Snn.


 Prof. Won Bruns of Tubingen, the emt- nent German surgeon, while conducting his investigations on gunshot wounds found that in the wounds made by modern small arm rifle projectiles the surface at the point of exit was generally very badly torn, and in such way as to indicate very considerable distention of the skin at that point He therefore requested Professors Cranz and Koch of Stuttgart to make in- vestigations to determine the exact condi- tion of the skin of a body rich in blood al the point of exit of shot, especially at the instant the projectile passed through the side of the body.
 The point to be determined was, first, whether marked dlstention or bulging out actually took place and secondly, at what instant-while the projectile was still in the body, after it had left 1t? For pre- liminary determination and with view to laying a foundation for these investfga- tions, the eXperimenters decided to use vessels filled with water and closed at the sides with rubber sheets in place of the bodies of animals The small-arm used was an experimental Mauser gun of milli metres .234 inch) caliber, firing smokeless powder and the ordinary projectile with velocity 100 meters greater than that of the S8 model Mauser gun.
 The only previous investigations bearing on this subject were those of Tillmann, who took cinematograph views of skull on being struck by a bullet. His appa- ratus allowed fifty successive pictures to be taken in one second, but he states that it is very desirable to increase this num- Der, because the most interesting phenom- ena probably take place between his first and second pictures.
 Professors Cranz and Koch used tin cyl finders, little less than inches long and inches in diameter, suspended horizontal ly, one end closed with parchment paper, the other with rubber sheet, the cylinder being filled with water. They were enabled to obtain instantaneous photographs at the instant the projectile was in any desired part of the cylinder-just within the trance membrane, or in the interior or just within the exit membrane, etc. Their apparatus for this purpose consisted of battery of Leyden jars, the current from which was interrupted by breaks at two points, one of which had a glass tube in- serted between the terminals to prevent for the time being the passage of the spark; the other was in the focus of parabolic reflector. The former could be placed at any point inside the cylinder, and the gun was so fired that the projectlle broke the glass tube, which caused a-spGrk 10 pass at both breaks, the second one serving 1o light up the cylinder, which was photo- graphed by a camera in the axis of the re- Hector.
 The first series of experiments showed that with the apparatus above described and the ammunition used there was no eVi- dence of any bulging out of the exit sur face up to the time the projectile reached this surface; the bulging began after the projectile had passed through While the proiectile is still in the interior the water flows in a jet through the entrance hole toward the gun, but the explosive action Of the contents of the cylinder, tearing the latter in all directions. takes place only after the bullet has passed completely through the cylinder.
 With larger and stronger cylinders and higher velocities very different results were obtained as was shown when wrought Iron cylinders, feet long and 54 inches in di- ameter, were used closed at the ends with rubber and parchment paper as before. The explosive action while the projectile was still inside was then distinctly perceptible and very energetic The projectfle lost Its velocity before reaching the exit wall, and was upset and fiattened at the front and much torn. and finally swept out by the jet at the entrance hole. The parchment paper at the exit hole was torn into zigzag form and bulged out toward the gun. The rubber sheet at the exit wall was torn Tn different ways, depending on it's tension; sometimes showing only small, round hole at others large, circular hoie-~ sometimes a slit
 With the-view to explain the cause of this explosive action of rapidly moving srnall-arm projectiles, other experiments were instituted The explanation reached by the experimenters Is as follows
 The rapidly moving projectile produces counression wave in front of it, and the result is a motion of translation Of the en- tire mass fired through, causing greater or smaller tearing effect on the containing walls, depending on their resistance. The action consists in the projectile giving up it's energy of motion to the body struck, when the lateral effect Cor explosive actton) is greater: the more direct this giving up of kinetic energy is Gin other words, the oreater the portion of the body that is struck directly) the smaller the amount of energy used up in overcoming cohesion in the body: the less the internal friction, and the smaller the mass of the body struck.
 When very large masses (of moist clay, for example) are struck. the hole inside or the mass is of a peculiar crater-llke 1orni' narrower at the entrance than just within, and finally tapering to point where the blfllet comes to rest. If sections are taken at various points through the crater-hke hole in the clay mass exit holes of different dimensions will be obtained. This eXpialns the different kinds of exit holes made by bullets for with a comparatively thin plate of clay the exit hole would be little larger than the entrance hole, and with thicker plate much larger: after passing the point of maximum widening of the crater-like hole the exit hole grows smaller and small CT. So it is in the human body. the resist ance offered corresponding to the thickness of the clay plate.
 The explosive action Is always greatest in the lines of least resistance, as Is known to be the case in a very remarkable man ner with high explosives.
 This subject is one of great interest in surgery and also explains at least some of the supposed uses of explosive bullets so much talked about in the Boer war.
 
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