Exsanguination incapacitate swine, poultry and domestic sheep, whereas a chemical is used for injured livestock. Continued pumping operation of the heart during exsanguination increases the rate of depletion, and thus hastens death, by raising the fluid pressure of the blood. Because the heart operates like a positive displacement pump, reduction of blood volume will not affect efficiency of cardiac output—deprivation of blood to the heart does gradually result in diminished function, but concurrently with similar death of other parts in the body. Quickly after the animal is incapacitated it is hung upside down by its hind limbs and an extremely sharp
History of scientific method by revising what the search for knowledge, particularly physical knowledge, might be. The first of these, philosopher and physician Francisco Sanches, was led by his medical training at Rome, 1571–73, to search for a true method of knowing ("modus sciendi"), as nothing clear can be known by the methods of Aristotle and his followers — for example, 1) syllogism fails upon circular reasoning; 2) Aristotle's modal logic was not stated clearly enough for use in medieval times, and remains a research problem to this day. Following the physician Galen's "method of medicine", Sanches lists the methods of judgement and experience,