116 EXPERIMENT STATION RECORD. 



20, p. 610), and Quartaroli,'^ that complex ions -are formed by the citric and 

 phosphoric acids, but can be brought into satisfactory accord with the ideal 

 that double decomposition takes place, as shown by Grupe and Tollens.'' and 

 Zulkowski and Cedivoda (H S. R., 14, p. 939). The differences between the 

 observed and calculated results in the cryoscopic determinations are regarded 

 as due to varying hydrolytic dissociation of the reaction products. 



The preparation of Petermann's solution, F. Zohken {Vhem. Ztg., 37 {1913), 

 No. GO, pp. 611, 612, fig. 1). — The preparation of ammonium citrate solution 

 from ammonia and citric acid is often disagreeable on account of the ammonia 

 which is given oft during the course of its preparation. The loss of this 

 ammonia obviously also causes some differences in the titer of the solution. 

 The author therefore proposes the use of an apparatus which consists of an 

 Erlenmeyer flask with a side neck and provided with a stirring device. To the 

 side neck is attached a wash bottle which contains some citric acid. This 

 citric acid absorbs the ammonia which is driven off and may be added later 

 to the main solution. 



The solubility of basic slag, J. Hughes {Chem. News, 107 {1913), No. 2774, 

 p. 39; abs. in Chem. Ztg., 37 {1913), No. 59, Repert., p. 267).— The presence of 

 from 2 to 3 per cent of free lime in Thomas slag seems to influence favorably 

 the solubility of the slag in a 2 per cent citric acid solution. Below this limit 

 the solution dissolves relatively less phosphoric acid and more calcium oxid. 



Method for the titration of sulphurous acid and sulphurous acid in the 

 presence of thiosulphuric acid, E. Bosshard and W. Grob {Chem. Ztg., 37 

 {1913), No. 46, pp. 465, 466; ahs. in Jour. Soc. Chem. Indus., 32 {1913), No. 10, 

 p. 532). — A mixture of sulphite and bisulphite is first titrated with hydrochloric 

 acid, using methyl orange as indicator. A saturated solution of mercuric 

 chlorid and some pure sodium chlorid are added, and the solution is titrated 

 with sodium hydroxid, using the same indicator. The normal sulphite present 

 is found by the first titration, and the alkali corresponding to the original bisul- 

 phite by subtracting from the total required that neuti-alized by the bisulphite 

 formed in titrating with acid. If thiosulphate is also present the sulphurous 

 acid may be determined by titration with hydrochloric acid, using methyl 

 orange as the indicator, and the bisulphite produced is then estimated together 

 with that originally present by titration with fifth-normal sodium hydroxid 

 solution against phenolphthalein. 



The thiosulphate is determined in another portion of the solution by adding 

 an excess of mercuric chlorid, 1 gm. of pure sodium chlorid, and 30 cc. of 

 fourth-normal ammonium chlorid solution, and titrating with an alkaline solu- 

 tion. The amount of thiosulphate is calculated after subtracting the alkali 

 used for the bisulphate by the following equation : 



Na2S203+2HgCl2+H=0=2HCl+Na:S04+S+Hg2Cl2. 



The determination of calcium as a tungstate, A. Saint-Sernin {Compt. 

 Rend. Acad. Sci. [Paris], 156 {1913), No. 13, pp. 1019, 1020; abs. in Chem. Ztg., 

 37 {1913), No. 51, p. 525). — This method, which is especially adapted to the 

 analysis of hj'draulic limes and cements, depends upon the precipitation of the 

 calcium with a solution of sodium tungstate. A crystalline precipitate con- 

 sisting of calcium tungstate is rapidly obtained which can be weighed after 

 drying. The results are calculated to calcium or calcium oxid. 



The industrial synthesis of sodium cyanid, C. Matignon {Rev. Gdn. Sci., 

 24 {1913), No. 23, pp. 882-SS6, figs. S; Sci. Amer. Sup., 77 {1914). No. 1991, pp. 



° Staz. Sper. Agr. Ital., 43 (1910), No. 7-9, pp. 545-558. 

 "Ber. Deut. Chem. Gesell., 13 (1880), pp. 1267-1270. 



