A n a 1 y t i c a1 C h em i s t r y, Titration of Acids by Metallic Sodium. By E. NEITZEL (Zeit. antcl. Chem ., 32,422-423) .-The author recommends anew Hartley's proposal (this Journal, 1873, 132) to employ weighed quantities of metallic sodium for the titration of standard acids. H e prefers to weigh the block of sodinm under petroleum which has been heated above 100" and fikered. For this purpose a beticker contaiiiing petroleum is tared on the balance, and the block of sodium, cut clean

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... a larger mass as rapidly as possible, is at once slipped into the petroleum and weighed. Such a block, of about 0.7 gram, gains only about 0.17 milligram during the 15 seconds required for cutting it out. The sodium is then withdrawn with tongs, and without regarding the adhering petroleum, is treated with 75 C.C. of 88-94 per cent. alcohol in a flask fitted with a perforated cork and glass tube. When all is dissolved, water and the indicator are added, arid the solution is ready for titration. Estimation of Chlorine in Water. By T. FAIRLEY (Awalpt, 18, 222).-The author confirms Young's statement (compare this vol., ii, 433) that water should be concentrated before titrating with silver nitrate and potassium chromate. But even then the resull will not be absolutely trustworthy if the water contains traces of alkali M. J. S. silicate.