TOURNIQUET. 693 



Tourniquet and Esmarch Bandage. 



A tourniquet is an instrument used to stop the circulation of 

 blood in a part, by pressure on the local blood-vessels. Usually, 

 it consists of an india-rubber tube, about f inch in diameter, and 

 is very rarely applied to any part, except the limbs. Its chief 

 value is in the prevention of bleeding during surgical operations, 

 such as those of neurotomy (p. 680) and removal of splints (p. 241), 

 in which cases the tourniquet is best applied two or three times 

 round the leg above the knee ; because, if put on below tlie knee. 



Fig- 179- — Arnold's Reliance tourniquet. 



its pressure will be unequally distributed, owing to the almost 

 total absence of muscles in that part. The most generally useful 

 form of tourniquet is Arnold's Reliance Tourniquet, an india- 

 rubber tube about 2-^ feet long, provided with a flat hook, through 

 which the other end, after compression by the finger and thumb, 

 can be passed (Fig. 179, p. 693). If this flat ring is of the proper 

 size, the end of the tube cannot be pulled through it, and it can 

 be released only by taking it out of the ring. We can improvise 

 a good tourniquet, by wrapping round the leg an ordinary ruVjber 

 tube, which can be obtained from any ironmonger, and securing 

 it by a reef knot (Fig. 180, p. 696). This tube will have to be 

 about i feet long, because it is not so elastic as specially made 

 tubes. Tourniquets are sometimes provided with a pad to b-e 



