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SCIENCE 



[N. S. Vol. LII. No. 1344 



industries. To do this latter, the industries must 

 lose their intense secrecy, and open their doors — 

 with proper safeguards — to the university men. 

 Eaw products, money, commercial organization, in- 

 dustrial chemists, all these we may have and yet 

 fail if we have not real research. 



The hydrogen exponent olassification of ijidica- 

 tors and some of its applications: I. M. Bern- 

 stein. (1) Definitions of terms used. (2) De- 

 termination of indicator constants: (A) Approxi- 

 mation method of Salessky; (B) colorimetrio 

 method; (C) Bjerrum's method. (3) Classifica- 

 tion of indicators according to exponents: (A) 

 Chart of same showing color changes; (B) com- 

 parison with Glaser's classification. (4) Appli- 

 cation of classification of volumetric analysis: 

 (A) Neutralization curves. (B) Selection and 

 concentration of correct indicator. (C) Prepara- 

 tion of new indicators. (5) Application of 

 classification to biological teehnic: (A) Determina- 

 tion of hydrogen ion concentration; (B) the se- 

 lection of correct indicator for physiological so- 

 lutions. 



The analysis of aromatic nitro compounds hy 

 means of titanous chloride: F. L. English. The 

 procedure for the analysis of aromatic nitro-com- 

 pounds as recommended by Knecht and Hibbert 

 (see "New Eeduction Methods in Volumetric 

 Analysis") has been modified and successfully ap- 

 plied to numerous typical nitro-eompounds of the 

 benzene series among which are m and p-nitrani- 

 lines, 0- and p-nitrophenols, o- and m-nitro-p-to- 

 luidines, two of the nitro-salicylic acid isomers, 

 dinitrobenzene, toluene and xylene, trinitrotoluene 

 and picric acid. The experimental figures given 

 show the method to be accurate to about 0.1 per 

 cent., total error. Eesults are given also to prove 

 the inapplicability of the method in its present 

 form to nitrochlor derivatives such as o- and p-ni- 

 trochlorbenzene and dinitroehlorbenzene, under- 

 reduction resulting in the first two cases and 

 over-reduction, probably at the expense of the 

 chlorine atom, in the last. When the chlorine is 

 in the side-chain, however, the reaction proceeds 

 more nearly quantitatively as illustrated by p- 

 nitrobenzyl chloride and dinitroxylyl dichloride 

 (l-3-CH„Cl-9^r-NO, benzene). The analytical 

 procedure, as well as the preparation, standariza- 

 tion and storage of the volumetric solutions, is 

 described in detail. 



Some physical constants of pure aniline: C. L. 

 Knowles. a sample of aniline was carefully 



purified by conversion to the oxalate, regenera- 

 tion and repeated vacuum distillation. Physical 

 constants were determined immediately without 

 undue exposure to the air. Freezing and boiling 

 point determinations were recorded by means of 

 a recently standardized platinum resistance ther- 

 mometer. The constants found are as follows: 



Freezing point — 6.24° C. 

 ■ Boiling point 184.32-184.39° C. at 760 mm. 

 Specific gravity 15/15 1.0268. 

 Eefractive index 20° C. 1.5850. 



On exposure to the air aniline absorbs moisture 

 very rapidly, taking up 2.4 per cent H;0 in 46 

 hours reducing the freezing point nearly 2° C. 

 Indications are that the freezing point is the best 

 criterion of .purity which may be calculated by 

 substitution in the following formula, (t) being 

 the observed freezing point and {x) the per cent, 

 aniline in the sample. X = 108.79 + 1.41 t. 



The absorption spectra of the nitric esters of 

 glycerol: E. Q. Adams. 



Tetramiethylquinolines : L. A. Mikeska. 



Naphthalene sulfonic acids. Some difficult sol- 

 uble salts of naphthalene sulfonic acids: J. A. 

 Ambler. 



A method for the qualitative detection of some 

 naphthalene sulfonic acids: J. A. Ambler. 



Synthesis of s-Xylidine: H. L. Haller. 



Alkali fusions. II. The fusion of sodium ben- 

 zene disulfonate with sodium hydroxide for the 

 production of resorcinol : Max Phillips and H. D. 



GiBBS. 



A synthesis of thymol from p. cymene: Mas 

 Phillips and H. D. Gibbs. 



The vapor pressure of phthalic anhydride : K. P. 

 Monroe. 



A new source of furfural and an investigation 

 of the preparation and properties of "furfural 

 green": K. P. Monroe. 



The absorption spectra of the nitric esters of 

 glycerol: Elliot Quinct Adams. Hepworth 

 (Jour. Chem. Soc, 115, 840-47 (1919)), from a 

 study of the absorption spectra of the nitric esters 

 of glycerol, concludes "(6) There does not ap- 

 pear to be any numerical proportionality between 

 the number of hydrogen atoms of the hydroxy! 

 groups displaced by nitro-groups and the degree 

 of absorption for any particular dilution." A 

 critical study of the results of Will (Ber. 41, 

 1107-23 (1908)), which have been accepted by 

 Hepworth, indicates that his designations a- and 

 /3- for the mononitrates should be interchanged. 

 Each nitrate radicle has an absorptive effect de- 



