AGRICULTUKAD CHEMISTRY — AGROTECHNY. 205 



solution of the clilorids, affords easy and exact means for the separation and 

 estimation of barium associated with calcium and magnesium. It is not recom- 

 mended for the separation of barium from strontium." 



Estimation of minimum quantities of calcium in the presence of a large 

 excess of magnesium, C. Liesse (Ann. Chim, Analyt., 16 {1911), A'o. 1, pp. 7, 

 8; abs. in Jour. Chem. 8oc. [London], 100 {1911), No. 580, II, p. 15Jf).— The ma- 

 terial under examination is dissolved in 25 parts of hydrochloric acid, 100 parts 

 of water are added to this, and the solution is neutralized with ammonium 

 hydrate, using phenolphthalein as the indicator. The precipitate which forms 

 (consisting of silica, alumina, and iron) is filtered off and to the filtrate enough 

 water is added to make 1,500 cc. for each gram of sample used. To the solu- 

 tion 4 gm. or more of ammonium oxalate is added and it is then acidified with 

 acetic acid. After 2 hours of standing, stirring several times during the 

 interval, the calcium oxalate is collected on a filter as usual, and weighed. 



Separation of strontium from calcium, L. Mosee and L. Machiedo {Chem. 

 Ztg., 35 {1911), No. 38, pp. 337, 338; abs. in Chem. Ahs., 5 {1911), No. 15, p. 

 2.}7.J). — The methods based on the following principles, according to these 

 authors, do not give good separations — the precipitation of strontium with 

 ammonium sulphate, the conversion of strontium oxalate into strontium sul- 

 phate with potassium sulphate, and the solution of calcium nitrate in strong 

 nitric acid. As anhydrous calcium nitrate was found to be soluble in both 

 ether and alcohol and barium and strontiiun nitrates insoluble, good separations 

 could be obtained. Amyl alcohol was found to offer no advantages over ether or 

 ethyl alcohol. 



The lime in basic slag-, J. Hendkick {Jour. Soc. Chem. Indus., 30 (1911), 

 No. 8, pp. 520-522; abs. in Chem. Abs., 5 {1911), No. 15, p. 2^75).— ''The author 

 extends his experiments [E. S. R., 22, p. 25] at the suggestion of W. Smith ^ 

 that the hydrolysis of NH4 salts had not been considered in measuring the basic 

 lime in slag by distillation with (NH4)2S04. Further experiments show that 

 the conclusions are not materially affected by this fact. Further tables are sub- 

 mitted showing that slag possesses a considei'able portion of lime capable of 

 acting as a base in the soil, and of neutralizing acids produced therein, as in 

 fertilizing with (NH4)2S04. In determining this basic-lime content, distillation 

 with NH4CI is sui:)erior to distillation with (NH4)2S04, as the former is less 

 hydrolyzed. The alkalis in glass are a much greater source of error in the 

 method than the factor of hydrolysis. Tables of slag analyses as to basic con- 

 tent are only of comparative value when the method is uniform." 



Rapid determination of sulphuric acid with the porous clay crucible, F. 

 Klein {Amer. Jour. Pharm., 83 {1911), No. 7, pp. 3-'f2-3-'f6, figs. 3).— A descrip- 

 tion and illustration of a porous clay ci'ucible with which it is possible, accord- 

 ing to thf author, to make a dozen or more determinations of sulphur in the 

 time which it usually takes to make a single filter determination. 



The analysis of copper mixtures meant for spraying purposes, E. Durier 

 {Ann. Falsif., // {1911), No. 29, pp. 133-138, figs. 3).— Particular attention should 

 be given to the proper sampling of spraying chemicals, as otherwise, according 

 to this author, erroneous conclusions are often drawn. This applies especially 

 to those mixtures which contain substances of various degrees of fineness, in 

 which the larger particles and most valuable portion (copper salts) during 

 transportation usually settle to the bottom of the sack, while the lighter and 

 inferior portion remains on top. Zonal analyses of the various portions of 

 the contents of such sacks are given for purposes of illustration. The cause 

 could not be attributed to an increase or decrease in moisture. 



o Jour. Soc. Chem. Indus., 30 (1911), pp. 253-256. 



