In the apparatus for steam distillation, the greater portion of the condensation is effected by the stream of water passing over the receiver. It is, therefore, necessary that the stream passing through the condenser should be sufficiently rapid to cause it to form a uniform film over the receiving flask. A 12-l. flask is even more efficient as a condenser than the 5-l. flask. It is important that the tube through which the vapors leave the distillation flask should be neither too short nor, especially, too narrow. Where the external diameter of the steam inlet tube is 5-8 mm., the internal diameter of this steam head should be not less than 28 mm. Were it less, the current of steam passing through it would be so rapid as to prevent small quantities of liquid from returning to the flask, and these would be driven over into the receiver. Much time can be saved by the use of the steam distillation apparatus described, especially when large quantities have to be handled. The above directions avoid the use of extraction methods, which not only consume more time but may lead to appreciable losses of material. If the downward condenser is of iron, the apparatus is even more efficient and the time for the steam distillation is halved. The percentage yields have been based on the amount of aniline taken. It would probably be more legitimate to base the calculation on the amounts of aniline taken and of nitrobenzene not recovered, since undoubtedly the latter is reduced to aniline during the course of the reaction. If this be done, the yield is found to be only 55 to 60 per cent of the calculated amount. In a number of experiments, the glycerol used contained an appreciable amount of water. Under these conditions, the yield of product is much lower. "Dynamite" glycerol containing less than half a per cent of water is best employed; U. S. P. glycerol contains 5 per cent of water and usually gives lower yields. 3. Other Methods of Preparation Quinoline has been produced by passing the vapor of allylaniline over red-hot lead oxide;[1a] by heating acrylideneaniline, or better, a mixture of aniline, glycerol and sulfuric acid;[2a] by heating aniline with glycerol and sulfuric acid, using nitrobenzene as an oxidizing agent;[1] by treating a mixture of glyoxal and _o_-toluidine with alkali;[2] by treating a solution of _o_-aminobenzaldehyde with acetaldehyde and alkali;[3] by heating methylacetanilide with zinc chloride;[4] by heating aminoazobenzene with glycerol and sulfuric acid;[5] by heating a mixture of aniline, glycerol and sulfuric acid with arsenic acid.[6] [1a] Ber. 12, 453 (1879). [2a] Ber. 13, 911 (1880); Monatsh. 1, 316 (1880). [1] Monatsh. 2, 141 (1881); J. prakt. Chem. (2) 49, 549 (1894), [2] Monatsh. 15, 277 (1894). [3] Ber. 15, 2574 (1882); 16, 1833 (1883). [4] Ber. 23, 1903 (1890). [5] Ber. 24, 2623 (1891) [6] Ber. 29, 704 (1896)