Heating/cooling methods sand bath

Other laboratory operations performed by the Alexandrian alchemists included solution, filtration, crystallisation, sublimation, and distillation. The art of distillation shows a steady improvement over the years. In the earliest form of distillation apparatus, the vapours ascending fi om the flask or bikos were condensed in the hood or ambix, and then ran down the spout into the receiver (Figure 2.4). The Arabs later used the name alembic for the condensing hood. This method of condensation was inefficient, and it was not until much later that water-cooled condensers were introduced. The alchemists employed several different kinds of furnace, and also introduced the sand bath and water bath for heating purposes. The water bath is reputed to have been invented by one of Zosimos s predecessors called Maria the Prophetess or Maria the Jewess. Today, when a pan of hot water is used to heat another vessel in the kitchen, the contrivance is still called a bain -Marie. 

Method B. Place 125 g. (106 -5 ml.) of diethyl phthalate and 25 g. of molecular sodium (sodium sand see Section 11,50,6) in a 500 ml. round-bottomed flask fitted with a reflux condenser and dropping funnel. Heat the flask on a steam bath and add a mixture of 122 5 g. (136 ml.) of dry ethyl acetate and 2 5 ml. of absolute ethanol over a period of 90 minutes. Continue the heating for 6 hours, cool and add 50 ml. of ether. Filter the sodium salt (VI) on a sintered glass funnel and wash it with the minimum volume of ether. Dissolve the sodium salt (96 g.) in 1400 ml. of hot water in a 3-htre beaker, cool the solution to 70°, stir vigorously and add 100 ml. of sulphuric acid (3 parts of concentrated acid to 1 part of... 

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