1919J AGRICULTURAL CHEMISTRY AGROTECHNY. 13 



charge the proper amount of fluid into the tubes planted in the infected wound. 

 The apparatus is said to be easily made and to operate with uniform regularity. 



Preparation of Dakin's solution from liquid chlorin by the gravimetric 

 method, S. R. Benedict (Surg., Gynecol., and Obstet., 27 (1918), No. //, pp. 886, 

 387). — Weighing the chlorin used in the preparation of Dakin's solution is said 

 to be preferable to measuring its volume on account of greater accuracy, 

 cheaper and less complicated apparatus, and more rapid manipulation. The 

 procedure for the preparation of 10 liters of the solution by the gravimetric 

 method is described in detail. 



The manufacture of chloramin— T, J. K. H. Ingris (Jour. Soc. Chem. Indus., 

 37 (1918), No. 18, pp. 288T, 289T ; abs. in Chem. Abs., 12 (1918), No. 23, pp. 2653, 

 265J(). — A method for the preparation of chloramin-T from the starting point 

 of toluene is described in detail. 



Preparation of perchloric acid from perchlorates, A. Vurtheim (Verslag. 

 Landbouwk. Onderzoek. Rijkslandbouicproefstat. [Netherlands], No. 22 (1918), 

 pp. 171-175). — The following method is described for the preparation of per- 

 chloric acid from alcoholic perchlorate residues consisting principally of cal- 

 cium, magnesium, and sodium perchlorate: 



After removal of the alcohol by distillation, the calcium and magnesium are 

 precipitated as carbonates by sodium carbonate and removed by filtration. 

 The filtrate is dried and an excess of hydrochloric acid added which precipitates 

 most of the sodium as sodium chlorid, leaving in solution a mixture of per- 

 chloric acid, sodium perchlorate, and hydrochloric acid. After the hydro- 

 chloric acid is removed by evaporation, the perchloric acid which remains is 

 considered satisfactory for potash determinations. 



Sulphuric acid determination in the presence of phosphoric acid, T. von 

 Fellenberg (Mitt. Lebcnsm. Untcrsuch. u. Hyg., Schweiz. Gsndhtsamt., 6 

 (1915), No. lf-5, pp. 191-195). — Experimental evidence is given to prove that in 

 the presence of phosphates the determination of sulphuric acid gives too high 

 results. It is stated that this error can be reduced to a minimum by adding the 

 hot barium chlorid solution drop by drop to the boiling, weakly acid solution 

 (about 0.13 cc. concentrated hydrochloric acid or 13 to 14 cc. N. hydrochloric 

 acid in 100 cc). 



The identification of acids of agricultural products, J. B. Rather and E. E. 

 Reid (Arkansas Sta. Bui. 156 (1918), pp. 3-32). — A method is described for the 

 identification of acids of agricultural products, both singly and in mixtures, by 

 melting-point determinations of the phenacyl esters formed by the action of 

 bromacetophenone on the alkali salts of the acids in dilute alcoholic solution. 

 Many of these esters were found to be solids easily purified by recrystallization 

 from alcohol and with convenient melting points. Formic, butyric, valeric, and 

 oleic acids gave liquid phenacyl esters, and asparaginic and gallic acids gave 

 gummy products with no definite melting points. Attempts to form satisfactory 

 solid derivatives of the liquid phenacyl esters were unsuccessful in the case 

 of the phenylhydrazones and oximes. The reagent has been successfully applied 

 in the identification of many acids in mixtures with other acids. Tables are 

 given of the results obtained. 



The authors conclude that the use of bromacetophenone as a reagent for the 

 identification of acids should prove especially valuable in the study of the 

 acids of fruits and other agricultural products. 



Determination of acidity in flour, T. von F'ellenberg (Mitt. Lebcnsm. Untcr- 

 such. u. Hyg., Schweiz. Gsndhtsamt., 6 (1915), No. 3, pp. 1^5-150). — A modifica- 

 tion of the Kreis-Aragon method (E. S. R., 12, p. 823) is described, which differs 

 from the original method as follows: (1) The titration is conducted in the cold 



