"I have lately been removing tin pluggings (the juices of the mouth having oxidated and dissolved away the metal, so as to expose the teeth to decay) from teeth which I plugged fifteen years ago (1818) for the purpose of re-stopping with gold, and have in almost every instance found the bone of the tooth at the bottom of the pluggings perfectly sound and protected from decay." (J. R. Spooner, Montreal, 1833.) In 1800 the number of dentists in the United States was about one hundred, and many of them were using tin foil for filling teeth. In 1822 tin was employed by the best dentists, with hardly an exception; it grew in favor, especially for large cavities in molars, and for a cheaper class of operations than gold, but tin was not generally used until 1830. ("History of Dental and Oral Science in America.") "Lead, tin, and silver corrode and become more injurious than the original disease, and will in every case ultimately prove the cause of destruction to the tooth, which might have been preserved by proper treatment." (Leonard Koecker, 1826, and "New System of Treating the Human Teeth," by J. Paterson Clark, London, 1829 and 1830.) "Tin in situations out of reach of friction in mastication, as between two teeth, is like the tooth itself apt to be decomposed by acidity unless kept very clean." ("Practical and Familiar Treatise on Teeth and Dentism," J. Paterson Clark, London, 1836.) Refer to what the same author said in 1829. "Tin is used as a plugging material." ("The Anatomy, Physiology, and Diseases of the Teeth," by Thomas Bell, F.R.S., London, 1829.) "Silver and tin foil, although bright when first put in a cavity, very soon change to a dark hue, resembling the decayed parts of the teeth which are of a bluish cast; besides this, they are not sufficiently pure to remain in an unchanged state, and frequently they assist in the destruction of a tooth instead of retarding it." ("Familiar Treatise on the Teeth," by Joseph Harris, London, 1830.) "Tin is objectionable on account of rapid oxidation and being washed by the saliva into the stomach, as it may materially disorder it; the filling becomes so reduced that the cavity in which it has been inserted will no longer retain it, and acid fruits influence galvanic action." ("Every Man his Own Dentist," Joseph Scott, London, 1833.) In 1836 Dr. Diaz, of Jamaica, used tin foil for filling teeth. "Gold is now preferred, though tin, from its toughness when in the leaf, is perhaps the most suitable. Americans are superior to British in filling." ("Plain Advice on Care of the Teeth," Dr. A. Cameron, Glasgow, 1838.) [Illustration: FIG. 1.] [Illustration: FIG. 2.] "Tin foil is used for filling teeth." (S. Spooner, New York, 1838, "Guide to Sound Teeth.") In 1838 Archibald McBride, of Pittsburg, Pa., used tin for filling cavities of decay.