To stop external bleeding, clean wound with water or liquid silver (I use Silver Shield).  Then open a capsule of yarrow and apply directly to the wound and apply gentle pressure.  Yarrow is a coagulant, astringent, as well as a blood purifier (among other things).  You may need to reapply a couple of times depending on the flow.  Historically, yarrow is also used for internal bleeding.  I have personally used this remedy many times on myself and with my pets.  It is a must to keep on hand.