1894.] on Destructive Effects of Projectiles. 237 



pressure in the small capillary vessels, changes which I may remark 

 incidentally are usually due to those disturbances in the central 

 nervous system which we call vaso-motor. Thirdly, the movements 

 of respiration are traced on the recording surface by means of rubber 

 tambours, known as Bert's and Marey's respectively. If the pressure 

 within the skull was also to be recorded, then a steel tube filled with 

 the salt solution was fixed into a trephine opening, and connected by 

 a rubber air-tube also with a Marey's tambour. Occasionally we put 

 on the same paper a record of the contraction of the rectus femoris 

 muscle, this latter being directly connected with a Fick's spring 

 myograph. At the bottom of the tracing is given, firstly, the 

 record of the movements of an electro-magnet signal (Smith's) 

 interrupted by a metronome beating seconds. The last line traced 

 is that from a Smith's signal in the circuit of a single cell, and 

 one of the wires from which is made of very slender brass and 

 fixed across the muzzle of the pistol or rifle, so that when the 

 shot leaves the muzzle it cuts it and breaks the contact (Woolwich 

 method). 



When a bullet of low velocity (600 f.p.s.) strikes the skull in a 

 glancing fashion, there is only a trifling disturbance of respiration, 

 but when the bullet enters the cranial cavity and sets up the powerful 

 hydrodynamic pressure before referred to, a very severe effect is 

 produced, namely complete arrest of the respiration and a slight fall 

 of the central blood pressure, this causing a similar feeble fall in the 

 peripheral blood pressure. A little later (5-10 sees.) than the arrest 

 of respiration a remarkable rise in the blood pressure occurs, this rise 

 continuing until the normal tension is exceeded. These observations 

 prove beyond doubt that the first cause of death is not what it is 

 usually supposed to be, and as taught in the text-books, namely arrest 

 of the heart and syncope, since, as you see, the heart goes on beating 

 although the respiration has completely stopped. Furthermore, if we 

 quickly perform artificial respiration we obtain recovery from the 

 otherwise fatal arrest. 



This suggests very strongly that the police and persons who are 

 trained in giving the first aid to the wounded should be taught that 

 with a gun-shot wound of the cerebral hemispheres, the proper thing 

 to do is to employ artificial respiration rather than the giving of 

 stimulants, &c. But, as you may well expect, the matter does not 

 stop here, nor is it so very simple, because we find that there are 

 certain conditions under which the secondary rise of blood pressure 

 does not occur. 



It is now quite evident that the fatal phenomenon of the gun-shot 

 wound of the cerebral hemisphere is in the first instance cessation of 

 the breathing, and I have now to indicate in detail how this is 

 produced by the hydrodynamic disturbance evoked within the skull 

 cavity by the energy of the bullet. It is perhaps necessary to first 

 remind you that the upper part of the spinal cord or medulla 

 oblongata contains the chief centre for the movements of respiration. 



