FEET, PERSPIRATION OF.—See SKIN, CANE or. ' FEL BOVIS (0X-GALL).—The fresh bile of the ox, Bos taunts. It has only recently been introduced into medicine as a stimulant to the biliary secretions. Ox-gall, either in the form of enemas or of pills, is of service in chronic constipation and obstipation due to insufficient activity of the liver. It is given in doses of about five grains.
FELON.—See R UN ROUND.
FENCING.—An excellent form of exercise which has been practised by man ever since he has had weapons. The practice is in vogue at the present day, and the weapons used are either foil or broadsword. Owing to the requirements of dexterity, of reliability of sight, and of strength of arm, it may be recommended to healthy persons of younger years. If the various cuts and thrusts are executed, not merely against a wooden manikin, but against an actual opponent, it is necessary to protect the head and body by masks and plastrons.
FENNEL.—See RENICULVN, FERMENTS.—Substances that act in some unknown manner on other substances, bringing about chemical changes, and yet not themselves entering into the reaction, have been termed ferments, or enzymes. Both inorganic and organic ferments arc known. Platinum black, manganese, and other metals, in finely-powdered forms, are known to show the characteristics of ferment action. The most important of the ferments, however, are of organic origin, and may be either of animal or of plant manufacture. The
digestive ferments pepsine and trypsine, from the stomach and pancreas respectively, play an important role in the breaking down of proteid foods ; while the ptyaline of the saliva and the aniy/opsine of the pancreas act on carbohydrates, rendering them capable of absorption into the lymphatics. Steapsine is another pancreatic ferment, and is indispensable in the digestion of fats. Other ferments are known in the human body, such as thrombine, or the fibrine ferment, the enzyme which causes the blood to clot. Oxidising ferments are known that behave in a manner similar to laccase of Japanese shellac. The body probably contains many important ferment-like sub stances which are not vet known.
Of the organised ferments, the yeast and bacteria plants are of particular interest, the former especially on account of their property of breaking down sugars to form alcohol, carbonic acid, and water. The bacteria also show' marked ferment action. Many of them set free a clotting ferment, as is seen in the clotting of milk, where an action takes place corresponding to the coagulation of the blood. A similar action is exerted by rennet on milk. The formation of plant jellies is caused by a similar clotting ferment tectase. The study of the ferments and of fermentation is as yet only in its infancy.