Anyhow, this and other customs in vogue in various parts of India and in many islands of Oceanica demonstrate that these peoples attribute great importance to the teeth. The substituting of gold teeth for those missing has been in use in Java from exceedingly remote times.[34] Dyeing the teeth black is considered a great embellishment among many races of Asia and Oceanica; this operation is sometimes preceded by another, viz., the filling up of the interdental spaces very cleverly with gold leaf.[35] In Sumatra and the neighboring islands many women file their teeth down to the gums; others file them into points; or partially remove the enamel so as to render it easier to apply the black dye; this being held to be the height of elegance. Men of high rank and condition dye their upper teeth black and cover the lower ones with fine gold plates, which in a full light produces what they consider a fine contrast. The natives of other islands gild the upper central incisors and dye the others black.[36] In Japan, the married women may easily be distinguished from the others by their black and shining teeth. The coloring preparation they use to blacken the teeth is composed of urine, raspings of iron, and a substance called _saki_. This mixture has a most unpleasant odor, and if applied on the skin acts as a caustic. Its action on the teeth is so powerful that they do not regain their whiteness even after a lapse of years. In applying this substance, and also for some time after, the women take care to preserve their gums and lips from its effects, as it would otherwise cause them to assume a dark blue tint.[37] The inhabitants of the Pelew Islands make use of the wild thistle and shell chalk to blacken the teeth. It is also the custom to blacken the teeth among the inhabitants of Tonkin and Siam, the women of the Maria Islands, and the single ladies of Java. Some of the peoples of Eastern India plane their teeth down to an even level; and from the habit of masticating areca nuts mixed with chalk and other substances, their lips and teeth are dyed red. At Macassar the natives have their teeth dyed red; they also substitute missing teeth by artificial ones made of gold, silver, or tombac.[38] Negroes, especially those of Abyssinia, very often file their incisors into points to resemble the form of the canines; this is in order to give themselves an air of greater ferocity. Murphy relates that the inhabitants of one of the islands of the Sound make an incision in the upper lip in a parallel line with the mouth, and large enough to allow the tongue to pass. After the margins have healed they have a great resemblance to the lips. This kind of artificial mouth is made to support a shell, carved in such a manner as to produce the effect of a row of teeth. The natives of the Sandwich Islands sacrifice their front teeth to conciliate the favor of their god Eatoa.[39]