DISEASES OF THE ORGANS OF CIRCULATION 69 



parts, including the vessel, are twisted (torsion of the spermatic 

 cord). 



(d) Heat in the form of the hot iron or the thermo-cautery is 

 an effective haemostatic in many cases of parenchymatous hemor- 

 rhage. The opening in the bleeding vessel is closed by a scab, 

 which acts as an aseptic bandage (cautery in amputation of the 

 tail). Cold (ice, cold water, ether spray) is less reliable; it checks 

 hemorrhage by contracting and narrowing the small blood-vessels. 

 Hot water at a temperature of 45 to 50° C. is recommended as a 

 good haemostatic for parenchymatous bleeding. Even hve steam, 

 100 to 120° C. (?), has been directed into the uterine cavity for 

 several minutes in persistent hemorrhage from the uterus in woman 

 (so-called vaporization of the uterus, atmocausis, zestocausis). 



(e) Drugs (haemostatics, styptics, antihemorrhagics, astrin- 

 gents, agglutinatives, rophetics) are used in external parenchy- 

 matous and in internal hemorrhages. They are ineffective in 

 external arterial and venous hemorrhages; in these cases surgical 

 methods (ligature, compression) are of greater service. The mode 

 of action of the styptics differs with the different drugs. Some 

 cause a contraction of blood-vessels, with narrowing of the lumen, 

 by direct action upon the muscular layer of the blood-vessel wall. 

 In this way, for example, nitrate of silver reduces the lumen one- 

 half. The contraction of the vessels reduces the amount of blood, 

 slows the circulation and finally causes stasis. Other drugs arrest 

 hemorrhage by causing coagulation of the blood, directly or indi- 

 rectly, and closing the lumen of the bleeding vessel by the resulting 

 thrombus. The solution of chloride of iron acts in this way. 

 Some drugs operate in both ways; e.g.j tannic acid and ergot. 

 Blood coagulation is also favored by decrease of blood-pressure. 

 Some drugs act in a purely mechanical way by agglutinating the 

 bleeding surface (agglutinative styptics), or by absorbing the 

 blood (rophetic or spongy styptics, e.g.y sponge). For practical 

 purposes styptics are divided into two groups: local and general. 



1. Local or topical styptics serve to arrest hemorrhage upon the 

 skin, accessible mucous membranes and, when administered by 

 inhalation, in the lungs. The most important are: solution of 



