VOL.7, NO. 9
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AN ASBESTOS CRUCIBLE
AN ASBESTOS CRUCIBLE This so-called asbestos crucible is a device intended for use in the general chemistry laboratory. It was designed for combustions which are of such intensity as to render a porcelain vessel unfit for further use. Economy is the only advantage claimed for it. It is satisfactory only in cases where contamination of the product by adhering asbestos lint is of little consequence. It has been used in the author's laboratory for the combustion of sucrose mixed with a chlorate, and for other similar reactions; It is prepared by the student from a circular disk of thin asbestos paper by exactly the same technic used in preparing a paper filter for a conical funnel. After folding and opening, the cone is supported in a small iron ring or in a clay triangle. If the crucible shows any tendency to open up, this is readily corrected by the use of a pin or small paper clip. It is heated from below by directing the flame against the thin side. Obviously, the crucible is intended to serve for one combustion only. A disk of 11 centimeters diameter supported, when folded, in a ring of 5 centimeters inside diameter has been found to be of convenient size.
