620 EXPERIMENT STATION RECORD. 



"Iu view of all the work doiie on the determination of starch in the sweet potato, 

 the Reinke method and Maercker's method are to he recommended, and of these the 

 first is perhaps the hest. . . . 



"Asboth's method, which consists in precipitating the starch with a standard 

 solution of barium hydrate, and then determining the excess of barium hydrate 

 with standard acid, was tried„but the results were exceedingly unsatisfactory, so 

 much so that I do not consider the results worth reporting." 



On the chemical properties of diastase and the occurrence of araban in dias- 

 tase preparations, A. Wr6rlewski {Ber. Dent. Chem. GeseU.,30 {1897), p. 2289 ; abs. 

 in Chem. Ztg., 21 {1897), Xo. 93, Bepert., p. 282). 



The estimation of carbonic acid in natural waters, C. A. Setter | Analyst, 22 

 {1807), Dec. pp. 312-319). 



The exact estimation of total carbohydrates in acid hydrolized starch prod- 

 ucts. G. W. Rolfe and W. A. Faxon {Jour. Amer. Chem. Soc., 19 {1897), Xo. 9, 

 pp. 698-703, figs. 8). — The authors give a formula for correcting the specific gravity 

 when specific rotatory power is known, factors, etc., and various tests of the accu- 

 racy of these 



A contribution to the spontaneous combustion of vegetable food and feed- 

 ing stuffs, F. Hoffmann ( Wehnschr. Bran., 14 {1897), p. 437 ; abs. in Chem. Ztg., 21 

 {1897), Xo. 85, Bepert., p. 233). 



Mechanical arrangement of fat-extraction apparatus, G. J Yolckening {Jour. 

 Amer. Chem. Soc, 19 {1897), Xo. 9, pp. 735-738, fig. 1). — This shows the arrangement of 

 sets of fat-extraction apparatus, generation of steam for heating the ether, etc. 



On the determination of dry matter in peat, II. Tkvllei: ( Landir. Vera. Slat., 49 

 {1S97), Xo. 1-2, pp. 145-161, fig. 1). — A discussion of the method, with the results of a 

 large number of determinations. 



On the speed of reduction of ferric alum by sugar, J. II. Long {Jour. Amer. 

 Chem. Soc., 19 {1897), Xo. 9, pp. 68S-698). 



On the determination of calcium, aluminum, and iron in phosphates, L. Lindet 

 {Ann. Chim. Analyt. et Appl., 2 {1897), Xo. 5, p. 291; abs. in Chem. Ztg., 21 {1897), Xo. 77, 

 Bepert.. p. 211). — The errors incident to the citrate method are pointed out and it is 

 recommended to dissolve the phosphate in boiling nitric acid and precipitate in very 

 dilute solution with ammonium molybdate. The method then proceeds as usual 

 except that the precipitate of ammonium-magnesium phosphate and the filter are 

 ignited separately to prevent reduction and loss of phosphoric acid. 



The quick determination of phosphorus, EL WKOWISZEWSKI {Stahl u. Risen, 17 

 {1897), p. 814: abs. in (hem. Ztg., 21 {1897), Xo. 87, Bepert., p. 248).— A method appli- 

 cable to iron and steel analysis. Dissolve 2 gin. in 30 cc. nitric acid (1.2 sp.gr.), 

 dilute to50cc, and filter. Evaporate filtrate to original volume, oxidize with potas- 

 sium permanganate, add hydrochloric acid to dissolve the manganese dioxid, cool, 

 and neutralize with ammonia. Warm to 60 ('.. add molybdic solution, shake for 

 5 minutes, and let stand ^ hour. Filter, wash the precipitate with 10 per ceut ammo- 

 nium nitrate solution, and dissolve in ammonia. Neutralize with hydrochloric acid, 

 add magnesia mixture and excess of ammonia, allow to stand ] hour in ice or snow, 

 shake 5 minutes, and filter. 



Determination of phosphoric acid in natural phosphates, E. Henin(.4hh. Chim, 

 Analyt. et Appl., 2 (1897), p. 285 ; abs. in Chem. Ztg.. 21 (1897), Xo. 77, Bepert., p. 

 211). — A form of Villier's method is used. 



Estimation of alumina in phosphates, H. Lasne and vox Grubber {Ztschr. 

 Angeiv. Chem., 1S97, pp. 276-278; abs. in Jour. Chem. Soc. [London], 72 (1897), No. 420, 

 II, p. 51S). — Lasne claims priority for the use of sodium hydroxid in the separation 

 of aluminum phosphate from iron and other phosphates. Von Grueber replies that 

 he was not acquainted with Lasne's investigations when he published his method. 



Estimation of sodium in the presence of potassium, F. F. Bkilsteix and O. von 

 Blaf.sk (Jlitl. Acad. Imper. Sci. St. Petersbourg, 33, p. 209; abs. in Ztschr. Analyt. Chem., 

 SC (1S97), p. 513; Jour. Chem. Soc. [London], 72 I 1S97 >. Xo. 420, II, p. 51S).— "To the 



