publisher. Not indexed. Not illustrated. 1910 Excerpt: ...sulphide in place of zinc. At first the cork on the flask containing the iodine and water must be loosened occasionally to allow the air to be displaced by the hydrogen sulphide. Shake the iodine and water mixture constantly to hasten the process. Describe what happens. Continue passing the gas until the solution no longer becomes brown on shaking. Warm and filter the solution. What is the residue on the filter? Distil the filtrate fractionally, figure 9, collecting first the portion that comes over between 99 and 100, and then the fractions boiling between 100-105, 105-110, and so on. Use a small flame and place a gauze under the distilling flask. Stop when the liquid is nearly all distilled off. Note the highest temperature reached. Pour the liquid left in the flask into a test tube and keep the series of distillates for the following experiments: Add silver nitrate solution to the different fractions, using only a part of the solution in the case of the two highest boiling fractions. At what temperature did the most concentrated acid distil over? Try the action of a portion of the strong acid on zinc. (?) Test with litmus paper the higher boiling fractions. (?) Warm some of the concentrated acid with a little powdered manganese dioxide? What substance causes the color of the higher fractions and of the residue? Test your conclusion by an experiment. Record the maximum.boiling temperatures of aqueous solutions of hydrogen chloride, hydrogen bromide and hydrogen iodide and the corresponding concentrations of these mixtures. (K. 50, 108, 115; S. 120, 163, 167.) 27. Properties of Chlorine. (Hood.) a. Pit up a 250 cc. flask with a drop funnel and delivery tube as shown in Fig. 10. Since chlorine gas destroys rubber rator (how judge?) fill four dry, wide-mouth...

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