Report of the Committee on Editing Tentative and Offical Methods of Analysis, the Association of Official Agricultural Chemists . he bulb, the total length of the thermometer being about 38 cm. The bulbshould be about 3 cm. long and 6 mm. in diameter. The stem of the thermometershould be 6 mm. in diameter and made of the best thermometer tubing, with scaleetched on the stem, the graduation to be clear cut and distinct. The thermometershould have been annealed for 75 hours at 450°C., and the bulb should be of Jenanormal 16 glass, moderately thin, so that the thermometer will be quick-acting. XX
Report of the Committee on Editing Tentative and Offical Methods of Analysis, the Association of Official Agricultural Chemists . he bulb, the total length of the thermometer being about 38 cm. The bulbshould be about 3 cm. long and 6 mm. in diameter. The stem of the thermometershould be 6 mm. in diameter and made of the best thermometer tubing, with scaleetched on the stem, the graduation to be clear cut and distinct. The thermometershould have been annealed for 75 hours at 450°C., and the bulb should be of Jenanormal 16 glass, moderately thin, so that the thermometer will be quick-acting. XXIII1 FATS AND OILS 303 13 DETERMINATION. Saponify 75 grams of the sample in a metal dish with 60 cc. of 30% sodium hy-droxid solution (36° Baum6) and 75 cc. of 95% alcohol by volume or 120 cc. ofwater. Evaporate to dryness over a very low flame or on an iron or asbestos plate,stirring constantly. Dissolve the dry soap in a liter of boiling water and, if alcoholhas been used, boil for 40 minutes to remove it, adding sufficient water to replacethat lost in boiling. Liberate the fatty acids by adding 100 cc. of 30% sulphuric. FIG. 12. APPARATUS FOR THE MELTING POINT DETERMINATION. acid (25° Baume) and boil until they form a clear, transparent layer. Wash withboiling water until free from sulphuric acid, collect in a small beaker andplace on a steam bath until the water has settled and the fatty acids are clear; thendecant into a dry beaker, filter while hot and dry 20 minutes at 100°C. Whendried, cool the fatty acids to 15°-20°C. above the expected titer and transfer to thetiter tube, 25 by 100 mm. (1 by 4 inches) and made of glass about 1 mm. in in a 16 ounce wide-mouthed bottle of clear glass, 70 by 150 mm. ( by 6 304 METHODS OF ANALYSIS [Chap. inches), fitted with a perforated cork, so as to hold the tube rigidly when in the standard thermometer so that it can be used as a stirrer, and stir themass slowly until the mercury remains stati
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