Making a seton consisted in slipping a thread that had been soaked in turpentine under the skin. This was followed by a violent organic reaction from the subject, along with significant suppuration. This practice was supposed to boost the animal's immunity. The slot cut into the tip of the needle was used to place the thread, which was then guided under the skin. An alternative was to directly inject an astringent agent directly under the skin, leading to a sometimes uncontrollable abscess. This process was known as "fixation abscess".