. Journal. Rep. Anal. Chem. 4, gramme of powdered citric acid is put in a test-tube, together with lOgrm. of concentrated colourlesssulphuric acid. The test-tube is held in a clamp, andsuspended in a beaker filled with water, which is nowkept at the boiling temperature for an hour. The solu-tion changes to a lemon-yellow liquid, and a consider-able disengagement of gas takes place. If the yellowcolour of the solution does not alter within an hour, thecitric acid was pure ; but in the event of its having con-tained only half per cent, of tartaric acid, the tint ofthe fluid changes altog
. Journal. Rep. Anal. Chem. 4, gramme of powdered citric acid is put in a test-tube, together with lOgrm. of concentrated colourlesssulphuric acid. The test-tube is held in a clamp, andsuspended in a beaker filled with water, which is nowkept at the boiling temperature for an hour. The solu-tion changes to a lemon-yellow liquid, and a consider-able disengagement of gas takes place. If the yellowcolour of the solution does not alter within an hour, thecitric acid was pure ; but in the event of its having con-tained only half per cent, of tartaric acid, the tint ofthe fluid changes altogether, becoming brown after 30 or40 minutes, and red-brown after an hours standing. Itis obvious that the crystals of citric acid employed mustnot contain pieces of wood, paper, etc.—E. G. C. Improved Burettes. Ducretet. Rep. Anal. Chem. 5,185. A CONVENIENT arrangement for use in laboratories ofsugar mills, distilleries, etc., is represented in the advantage consists in the adjusting of the zero. point without pouring in or out, and without loss ; alsoin the rapidity with which tests can be made, and thecomplete projection of the contents from the air. K isthe reservoir for the standard solution, S a heavy sup- THE JOURNAL OF THE SOCIETY OF CHEMICAL INDUSTRY. 553 port, I! the burette divided into Sec, A a holder for thesame, P a pineh-cock, P1 an indiaruhher ball with anopening o, T junction between B and R, F glass-stopperof the reservoir with the opening O8, V mucinwith the rod a. R is tilled with solution through F, andthe air removed from P by compression and o Liquid is thereby drawn up from R to I!, and thezero is each time adjusted by the flow through T. Thevessel V is more convenient than a tlat one, and the roda is for taking samples.—H. A. 1!. Volumetric Estimation of Carbon Bisulphide in Stilpho- carbonates. Falieres. Rep. Anal. Chem. 4, 219,Tex grammes of the sulphocarbonate (winch imeasured off after the specific gravity has been de-
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