AGRICULTURAL CHEMISTRY. 1109 



or Kji'klalil-Uiinuin.t,' iucHkhI. The siiui of (1) and (1!) fe'ivos tlio total 

 iiiti-ojxcii." 



Determination of sodium and potassium in silicates, J. K. Thomskn {Jour. 

 AiHcr. Clirni. ^•of•„ JO {l!)()S), Nu. 3, pi). .',.iO, //^/).— A method of dotermining 

 sodium and potassium in clay and silit-atos which can bo decomposed by sul- 

 phuric and hydrofluoric acids is descrilied. 



The determination of phosphoric acid in Thomas slag- by the Grete method, 

 C. II. Kktnku {('Ikiii. W(< hhl.. ) ( lUOl ). int. I'tl-lli'i; <tl>s. in Cliciii. Zciilltl., IHOS, 

 1, \o. 2, pp. 1()S, nil); .Jour, riicin. tioc. [London], !)', {IHOS), No. 5.'/3, II, p. 

 O'l). — The author adapts the Grete method of titration with selatin-molybdic 

 solution to the determination of total phosphoric acid in Thomas slag as fol- 

 lows: Dissolve 10 gm. of the fine-ground slag in 50 cc. of concentrated sulphuric 

 acid, shaking vigorously and heating until white fumes begin to form. Dilute 

 to .'jOO cc, mix, and filter after standing 12 hours. Neutralize 1*5 cc. of the 

 filtered solution with ammonia, add 20 cc. of ammonium nitrate solution (1:2), 

 a teaspoonful of powdered potassium nitrate, and 15 cc. of nitric acid (1.2 sp. 

 gr.). heat to boiling, and titrate. 



The method of Trillat and Turchet for the determination of ammonia in 

 waters, A. Corsini (Gior. li. Sac, Ital. Iff., 2S {1906), Xo. S, pp. 119-131; abt; in 

 Ann. Chim. Anahjt., 13 {1908), No. 2, p. 75). — On the basis of his tests of this 

 method (E. S. R., 17, pp. 112, 113) the author recommends it for the follow- 

 ing reasons: It is more sensitive than the Xessler process and requires only 

 such sul>stances as are found in all laboratories. 



On the importance of the qualitative detection of iron in water, H. Klut 

 (AUff. Britu. II. Hopfcn Ztff., ^S {1908), No. 39, pp. J,01, .',0^).— Various simple 

 tests are descril)ed. but for ordinary waters preference is given to the use of 

 10 per cent sodium sulphid. 



Ash constituents of cereals, W. P. Gamble {Ann. Rpi. Ontario Agr. Col. and 

 Expt. Farm, 33 {1907), pp. 85-89). — A comparison of the Shuttleworth method 

 (E. S. R., 11, p. 304; 12, p. 30S) and the official method in the examination of 

 the ash constituents of a sample of wheat (grain and straw) is reported. 



Loss of phosphoric acid in ashing- of cereals, S. Leavitt and J. A. LeGlekc 

 {Jour. Anicr. Client. Noc. 30 {1!)0S), No. 3, pp. 391-39Jt). — The results obtained 

 with a number of samples of wheat by various methods of incineration are 

 reported. These show " that the temperature of ashing below fusion Is not 

 so important a factor where only the percentage of ash is desired, but when 

 determining the phosphorus as pho.sphoric acid in ash the greatest caution nnist 

 be observed to keep the temperature below the volatilization point of the com- 

 bined phosi)horus." 



A new method for the rapid estimation of dry matter in wheat gluten, W, 

 Rremeb {Ztschr. Cntcn^uch. Nnhr. n. Gcniiit.snitl., 1.) {1907), No. II, pp. G82-68(), 

 fiffs. 3). — In the method described the wheat gluten is brought iu close contact 

 with porous |)lates which al)sorl) the water. 



Determination of starch in potatoes, L. I'eli.et and Metillon {Ann. Chim. 

 AnaJyt., 13 {1908), No. 1, pp. 9-12, fig. /).— A study of methods. 



The Ley honey test, M. Koehnek {Clicin. Ztff., 32 {1908), No. 8, p. 89). — 

 Ley" reports that artificial honey with ammoniacal silver solution gives a 

 silver precipitate, while natural honey gives a fiuon^scent solution. According 

 to the author's investigations, the fiuore.sceut condition is due to the presence 

 of colloidal silver, a condition induced by a num]»er of bodies of high molecular 

 structure, including protein among others. Apparently this reaction is caused 



Tharm. Ztg., 47 (1JX)2), p. U03. 



