Chemistry and Physics. 321 



a volume less than that of the larger bottle, the whole was trans- 

 ferred to the latter at a temperature below 20°, which was used 

 as the temperature for weighing, and the bottle was filled with 

 water, the contents thoroughly mixed, and the whole finally 

 weighed. To obtain the mother-liquor free from the precipitate, 

 the contents of the bottle were transferred to a test-tube and 

 whirled in a centrifugal machine. For settling most precipitates 

 less than one minute was required, while in no case was it neces- 

 sary to spin the apparatus more than three minutes. The clear 

 liquid was then drawn off by means of a dry pipette, and its specific 

 gravity was taken in the smaller Geissler bottle. The author has 

 applied the method to the determination of chlorine as silver 

 chloride, sulphur as barium sulphate, calcium as oxalate, phos- 

 phoric acid as ammonium phosphomolybdate and invert sugar by 

 means of the cuprous oxide precipitated, with very satisfactory 

 results. The method requires that the composition of the pre- 

 cipitate should be constant, although it need not be exactly 

 known. It was found that the specific gravity of aluminium 

 hydroxide varies with the time that elapses after precipitation, 

 so that the method is not yet applicable to the determination of 

 this substance. It is expected that the method will find con- 

 siderable application, particularly for rapid work in technical 

 analysis, but it requires very accurate specific gravity determina- 

 tions where quantities of about one gram are taken, a circum- 

 stance which will probably limit its adoption by analytical 

 chemists. — Jour. Amer. Chem. iSoc, xxiii, 644. h. l. w. 



3. Europium, a New Element. — By a long series of fractiona- 

 tions with magnesium nitrate Demar^ay has separated an earth, 

 intermediate between gadolinium and samarium oxides, of suffi- 

 cient purity to show no samarium lines, and only mere traces of 

 gadolinium lines in the spectrum. The solutions give absorp- 

 tion-bands, and when traces of calcium sulphate are added to the 

 oxide a brilliant phosphorescent spectrum is produced. The 

 approximate atomic weight 151 is mentioned, but no details in 

 regard to the determination, nor any account of the chemical 

 properties of the substance are given. Numerous spectrum lines 

 are described, however, and the name given above is proposed 

 for the element. — Chem. News, lxxxiv, 1. h. l. w. 



4. Research Papers from the ICent Chemical Laboratory of 

 Yale University ; edited by Frank Austin Gooch, Professor 

 of Chemistry in Yale University. In two volumes : Vol. I, 

 pp. xiv, 411; Vol. II, pp. x, 415. New York, 1901 (Charles 

 Scribner's Sons, price $7.50 net). — This work forms part of the 

 " Yale Bicentennial Publications," a series of volumes prepared 

 by the Professors and Instructors of Yale University and issued 

 in connection with the Bicentennial Anniversary to be held 

 Oct. 20-23 of the present year ; the series is designed as " a par- 

 tial indication of the studies in which the University teachers are 

 engaged." 



The Kent Chemical Laboratory established at New Haven 



