460 BUREAU OF ANIMAL INDUSTRY. 



HEMOSTASIA. 



B}^ this term is meant the checking of the flow of blood. It may be 

 accomplished by several methods, such as compress bandages, torsion, 

 hot iron, and ligatures. The heat from a hot iron will cause the 

 immediate clotting of the blood in the vessels, and this clot is further 

 supported by the production of a scab, or crust, over the portion 

 seared. The iron should be at a red heat. If at a white heat the tissue 

 is charred, which makes it brittle and the bleeding is apt to be renewed. 

 If the iron is at a black heat the tissue will stick to the iron and will pull 

 away from the surface of the wound. Cold water and ice bags quickly 

 stop capillary bleeding, while hot water is preferable in more excess- 

 ive hemorrhages. Some drugs, called styptics, possess the power of 

 contracting the w^alls of blood vessels and also of clotting the blood. 

 A solution of the chloride of iron placed on a wound alone ov by 

 means of cotton drenched in the liquid produces a rapid and hard clot. 

 Tannic acid, alum, acetic acid, alcohol, and oil of turpentine are all 

 more or less active in this respect. To check bleeding from large 

 vessels compression may be adopted. When it is rapid and dangerous 

 and from an arter}-, the fingers may be used for pressing between the 

 wound and the heart (digital compression), but if from a vein, the 

 pressure should be exerted on the other side of the wound. Tour- 

 niquet may also be used by passing a strap around the part and tight- 

 ening after placing a pad over the hemorrhage. The rubber ligature 

 has now replaced the tourniquet and is bound tightl}^ around the limb 

 to arrest the bleeding. Tampons, such as cotton, tow, or oakum, may 

 be packed tightly in the wound and then sewed up. After remaining 

 there for twenty -four or forty-eight hours they are removed. Bleed- 

 ing may sometimes be easily checked by passing a pin under the vessel 

 and by taking a horse hair and forming a figure 8 by running it 

 above and below the pin, thus causing pressure on the vessel. Tor- 

 sion is the twisting of the blood vessel until the walls come together 

 and form a barrier to the flow of blood. It may be accomplished by 

 the fingers, forceps, or by running a pin through the vessel, turning 

 it several times, and then running the point into the tissue to keep it 

 in a fixed position. 



Ligation is the third method for stopping a hemorrhage. Seize the 

 blood vessel with the artery forceps, pass a clean thread of silk around 

 it, and tie about one-half inch from its end. The silk should be steril- 

 ized by placing it in an antiseptic solution so as not to impede the 

 healing process or cause blood poisoning or lockjaw, which often fol- 

 lows the ligation of a vein with unsterilized material. Sometimes it 

 will be impossible to reach the bleeding vessel, so it is necessary to 

 pass the ligature around a mass of tissue which includes the blood 

 vessel. Ligation is the most useful method of arresting hemorrhage, 



