530 OPERATIONS ON THE CIKCULATORY SYSTEM. 



bleeding svirface by means of some combustible substance which 

 will furnish more solid materials for the protective scar. A loop 

 of hair, or some pulverized rosin, placed upon the wound, and 

 burnt with the cautery, often fulfills the requu'ements. For hem- 

 orrhage from parts below the surface, the edges of the wound 

 must be separated before the cautery is introduced, to prevent its 

 coohng before reaching the proper point of application. When 

 the eschar is well formed and estabhshed it should be left without 

 interference to complete the process of sloughing. 



The thermo-cautery, with which the required heat can be re- 

 tained at a uniform degree, is one of the best instruments for 

 the application of this mode of hemostasia, there being no need 

 of removing it until an eschar of sufficient thickness has been ob- 

 tained. 



Surgical Hemostatics. 



Among the numerous surgical means of obtaining both per- 

 manent and definitive hemostasis, there are three which principally 

 merit our attention : compressioti, ligature and torsion. 



(A) Compression. — We have already referred to this method 

 while considering the subject of temporary hemostasia. There 

 are cases in which it acts as an excellent mode of permanently 

 controlling hemorrhage, whether proceeding from arterial, venous 

 or capillary sources, and equally whether from a large surface or 

 from a deep cavity, where the origin of the hemorrhage cannot be 

 distinctly located. Still, for arterial hemorrhages it is only effica- 

 cious for vessels of small or medium size, or when the wounds are 

 of small dimensions. There are secondary circumstances which 

 determine the designations of certain variations of pressure. One 

 is the situation of the vessel, relatively to that of the bleeding 

 orifice, when the pressure, to be effective, must therefore be direct 

 or lateral, and with the latter, either mediate or immediate. Some- 

 times, again, it is applied at a distance from the bleeding point, 

 and in an indirect manner, and involves an alternative between 

 l^higging and direct compression. It is aj^plied to the wound 

 itself when the vessel has been cut directly across. It is usually 

 effected by covering or fiUing the wound with a dressing of 

 balls of oakum applied directly upon the bleeding orifice, and 

 covering these with pads, increasing in dimensions as they become 

 more superficial. The whole apparatus is submitted to pressure 



