20 PRACTICAL ORGANIC CHEMISTRY with wire gauze. Very rapid drying is thereby obtained, and any acid or basic vapours which may be evolved are absorbed, the interior of the desiccator thus remaining clean and odourless. This is of particular advantage when drying a substance, e.g., an amine hydrochloride, which has been recrystallised from concentrated hydrochloric acid, and which would otherwise fill the desiccator with hydrogen chloride as drying proceeded. If a compound has been recrystallised from petrol, benzene, etc. , some freshly cut shavings of clean paraffin wax should be added to the calcium chloride in (A) or to the sodium hydroxide in D. The surface of the wax absorbs organic solvent vapours (particularly the hydrocarbons) and the last trace of such solvents is thus readily removed from the recrystallised material. When using a desiccator, the recrystallised material in the Buchner funnel should be transferred to a piece of clean glazed paper with the aid of a spatula, and the last traces carefully
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