As well say everything should be made only of iron, or steel, or wood, as that every tooth should be filled with gold; or, as _equally ridiculous_, that the amalgam or some one of the plastic fillings should be the only material used. It is not _necessary_ to found a _creed or departure_ on a law of _incompatibility_ to tooth substance. We need not look so far into the unknown and unknowable. We poor, short-sighted creatures must have the tangible; not a hypothesis on a _supposed theory_. Any one with half an eye can see just where the incompatibility is; not between gold and dentos, but between dentos and untutored and unskilled brain and hands to _carry out the law of adaptibility_--the correlation of forces involved. One skilled in the use of the mallet, with the rubber-dam and a substantial starting point, with walls ever so frail, can perfectly impact and complete the work in gold filling, _provided the surroundings are there_. But allow _one little vacuum_ between the tooth substance and the filling, and a _capillary tube_ will be formed to suck up _fermentable material_; and the _acid generated_ will act on the tooth whether it be filled with gold, amalgam, oxyphosphate, or gutta-percha. A thousand capillary tubes making porosity in the gold or the amalgam, will not do it; but if there is one, however small, between dentos and filling, destruction is sure.--_Transactions of the Odontological Society of Pennsylvania._ ARTICLE VII. SOME METHODS OF SEPARATING TEETH WITH WEDGES. BY DR. DWIGHT M. CLAPP, OF BOSTON. [Read at the joint meeting of the Massachusetts and Connecticut Valley Dental Societies, held at Worcester, Mass., June, 1885.]