New Form of Safety Pipette. A. K. REFIRMAN ( J . h l . Eng. Chem., 1917Chem., , 9, 1047.-A three-way tap is attached to the top of an ordinary pipette by means of a short length of rubber tubing and a rubber bulb fitted with suitable valves is connected with the upper limb of the tap. The pipette is filled by pressing and releasing the bulb. The t a p is then turned so as t o admit air t o the pipette, by which means tlie level of the liquid is lowered t o tlie Preparation of Ammonium Citrate

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... lution and the Estimation of Insoluble Phosphoric Acid. PHILIP McG. S'HUEY ( J . Ind. Eng. Chein., 1917, 9, 1045.-Neutrral ammonium citrate solution may be prepared by dissolving 1814.37 grams of citric acid in 6961 C.C. of water and 1760 C.C. of 28% ammonia, the water and aniinonia being measured a t 23O. The insoluble phosphoric acid in acid phosphate may be estimated with practically identical results, whether or not tlie weighed portion has been washed previously with water, and preliminary washing of samples coiltaining cyanamide does not appear to be necessary. T t may be important t o use a neutral ammonium citrate solution in the case cf ground tankage, whale guano, meat guano, fish, and similar matew. P. s.