DENTIFRICES This is a general term including all tooth powders, pastes, and washes for the teeth. The principal ingredi ents of these preparations are various substances in powdered form that are capable of exerting a gentle friction on the teeth and also have antacid, ab sorbent, or other useful properties, as chalk, Armenian bole, cuttlefish bone, charcoal, orris root, and Peruvian bark. To these may be added mild alkalies, and other substances having cleansing properties, as borax, bicar bonate of soda, and castile soap; astringent substances as alum and tannic acid; and agreeable vehicles as powdered sugar, rock candy, honey, sirup, and sugar of milk. Any of these mixtures may be perfumed with a few drops of any of the essential oils or essences, or colored by the ad dition of finely pulverized red coral, rose pink, cochineal, dragon's blood, or red sanders for red; ocher for yel low; indigo for blue or violet. Vari ous other substances having specific properties too numerous to mention may be added.
Prepared Chalk is the most univer sally popular ingredient in tootb powders, as it is cheap, safe, and ef fective, and tends to neutralize any acids that may be present in the mouth.
Bole is an earthy substance similar to clay, which is found in veins and fissures of basalt and other rocks in various parts of the world. It has a greasy feeling when rubbed between the fingers, and is slightly sticky on the tongue. There are several kinds of bole found in different localities, of which the Armenian bole has a red tint and is used in tooth powders to im part that color and also because of its absorbent and astringent properties.
Magnesia. — Carbonate of magne sia or " magnesia alba " is a white powder which is valuable because of its absorbent qualities and its power to neutralize acids that may be pres ent in the mouth. It is used in medi cine for acid dyspepsia. Hence it is entirely safe and a very effective in gredient in tooth powder.
Charcoal is a form of carbon ob tained by charring wood or by heat ing it in close vessels. Charcoal va ries according to the method by which it is produced. The best char
coal for toilet purposes is areca-nut charcoal, but this is expensive and often adulterated. Next best is the sort of charcoal used as an ingredi ent of gunpowder made of hard, non resinous wood, or soft wood such as willow and poplar, by roasting in iron cylinders. Charcoal has an ex traordinary capacity for absorbing gases. It cannot be melted or dis solved in acids, will not decay, and is not affected by ordinary tempera tures. It is et very poor conductor of heat. On account of its property of absorbing gases, it is used in medi cine in certain forms of dyspepsia, also to preserve flesh or sweeten it when tainted. As an ingredient of tooth powders, it tends to sweeten and purify the breath.
Cuttlefish Bone.—This substance is the shell of et mollusk of world-wide distribution. It is sold in powdered form under the name of "pounce" for tooth powder and other purposes. It has some value in neutralizing acids, but is less valuable for this purpose than chalk or magnesia. It is also harsher in its scouring effect, for which reason it is, in small quan tities, a valuable ingredient in tooth powders. It must, however, be finely powdered and used with caution.
Myrrh.—This is a reddish-brown brittle substance obtained from the juice of a small tree growing in Ara bia and vicinity. It occurs in resi nous lumps, has a fragrant odor, and u bitter aromatic taste. It has been used for ages, on account of its fra grant perfume, as an ingredient in incense, perfume, and salve. It acts as a tonic on the mucous membranes and hence is much used in mouth washes to harden and strengthen the gums and is good for sore throat and canker.
Cinchona Bark, or Peruvian Bark, is obtained from a fragrant evergreen tree growing in South America which produces the alkaloid quinine of so much value in medicine. Quinine is an indispensable tonic in the cure of intermittent fevers and debilitating diseases. It is used in medicine prin cipally in the form of the sulphate. And the bark itself is much less used than formerly. The pulverized bark has valuable tonic and astringent properties.