410 EXPEEIMEXT STATION RECORD. 



The voliunetric determinatioii of phosphoric acid in calcium phosphate, 

 I. M. KoLTHOFF (Pharm. M'eekhl., 52 {1915), No. 29, pp. 1053-1055). — A weighed 

 quantity of the phosphate is dissolved in dilute hydrochloric acid, rendered 

 neutral to dimethjiaminoazobenzene, and made up to a definite volume. A solu- 

 tion of disodium phosphate with the indicator is recommended to be used for 

 comparison. To an aliquot portion an excess of sodium oxalate neutral to 

 phenolphthalein is added and the solution titrated with tenth-normal alkali. 

 One cc. of tenth-normal alliali is equivalent to 7.1 mg. P-Os. The presence of 

 carbonate in the phosphate does not interfere with the determination. 



The method may also be applicable to the determination of phosphorus in 

 urine. 



Detection of various mineral and alkaloidal poisons in waters, P. Bbeteau 

 {Jour. Pharm. et C'him., 7. ser., 12 {1915), No. 3, pp. 68-73). — A procedure for 

 the separation of alkaloidal from mineral itoisons in waters is outlined, and 

 tests for the detection of certain alkaloids (brucin, colchicin, atropin, morphin, 

 strychnin, and veratrin) in the water are given. The separation of copper, anti- 

 mony, arsenic, barium, mercury, lead, zinc, and the cyanids is described in detail. 



The determination of gases dissolved in waters and effluents, A. A. Swan- 

 son and G. A. Hulett {Jour. Amer. Chcm. Sac, 31 {1915), No. 11, pp. 2490-2500, 

 figs. 2). — The authors describe two new pieces of apparatus, illustrated by 

 figures, for the determination of dissolved gases in water. Proce<lures for the 

 determination of oxygen, carbon dioxid, and nitrogen are given. The experi- 

 mental data submittetl indicate that gi'eat accuracy is possible with the method. 



The determination of nitrog'en contained in vegetable matter according to 

 the Gunning- Atterberg method, A. N. Lebediantzev {Zhtir. Opytn. Agron., 

 16 {1915), No. 2, pp. 95-105). — Experiments by the author show that a loss of 

 nitrogen in the method (E. S. R., 10, p. 605) occurs when the correlation between 

 sulphuric acid and potassium sulphate becomes too narrow. This loss can be 

 obviated by using an abundant amount of potassium sulphate and by increasing 

 the amount of the sample used in the determination. For material rich In fat 

 1.5 gm. sample is recommended ; for other materials. 2 gm. There is no loss of 

 nitrogen from boiling for various lengths of time after the oxidation is complete 

 provided long-necked Kjeldahl flasks are used. The substances used in the 

 experiments were rye, wheat, maize, flax, potatoes, red beets, and seeds of the 

 poppy, flax, and sunflower. 



Determination of chlorin in vegetable matter, D. J. de .Tong {Chem. Weekbl., 

 12 {1915), No. 26, pp. 592-594; abs. in Chem. Abs., 9 {1915), No. 17, p. 2363).— 

 The sample, usually from 10 to 15 gm.. is treated with 10 cc. of a 10 per cent 

 solution of sodium carbonate. The material is then ignitetl and chlorin deter- 

 mined in the melt in the usual manner. By this procedure there is no loss by 

 volatilization. 



The determination of volatile esters in citrus oils and extracts, A. R. 

 Albright and C. O. Yoxjng {Jour. Amer. Chem. Soe., 37 {1915), No. 10, pp. 2382- 

 2387). — Condensation with semicarbazid is recommended as a general proce- 

 dure preliminary to the determination of the saponification value of oils when 

 aldehydes are present. For the determination of the volatile esters the authors 

 propose the following manipulation : 



"First, the terpene fraction is removed as follows: One hundred gm. of the 

 oil is weighed into a three-bulb Ladenburg flask, the fla.sk hung in a hemi- 

 spherical iron air bath, connected with a pump producing a vacuum of from 

 2 to 5 mm., a small flame placed below, regulated to give a slow rate of distilla- 

 tion (not exceeding from 18 to 20 drops per minute), and the process not 

 disturbed until limonene ceases to come over. 



