Identifier: practicalmethods00gatt Title: Practical methods of organic chemistry Year: 1901 (1900s) Authors: Gattemann, Ludwig. [from old catalog] Subjects: Publisher: [n.p.] Contributing Library: The Library of Congress Digitizing Sponsor: The Library of Congress

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Text Appearing Before Image: ploy run-ning water for cooling pur-poses if to the outlet tube ofthe flask a wide glass tube50 cm. long (extension tube)is connected by a cork (Fig.18). With still higher boil-ing substances even this issuperfluous, since the con-densation tube of the frac-tionating flask, provided itis not too short, will sufficefor the condensation. If a small quantity of a substance is to be distilled, and it isdesired to avoid the loss of substance necessarily incident to theuse of a condenser, the distillation even of low boiling compoundsis conducted in a small distillation flask as slowly and carefullyas possible, the source of heat being a minute flame (the so-calledmicroburner). If large quantities are to be distilled, a condenser is always used,since when other condensation apparatus is employed, the tubefinally becomes so hot that the vapours are not completely con-densed. If the vapours of a substance attack corks, the outlettube is inserted far enough into the condenser or extension tube

Text Appearing After Image: 22 GENERAL PART so that the vapours do not come in contact with the cork. Butgenerally a cork is not used; the outlet tube being inserted suffi-ciently far into the condenser. Heating. — Low boiling substances (those boiling up to about8o°) are not generally heated over the free flame, but on the water-bath gently or to full boiling. Frequently it is more convenientto immerse the bulb of the fractionating flask as far as the levelof the liquid which it contains in a dish or beaker filled withwater, which is heated gently or strongly as the case requires.Low boiling substances may also be heated by immersing the bulb

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