AGRICULTURAL CHEMISTRY. 703 



The determination of phosphoric acid by the Pemberton method, (!. II. (I. 

 Lai.krs iZtsi-ln: AiKihit. ('lit in., .'/?' (IDOS). Nn. 9-10, />/). .767-^77/; nhx. in 

 Chcni. Zcnthl., lUOS, II, Xd. Id. pp. I.il!), l.iSO). — Comparisons of tho jrravi- 

 niotric method with tlu' orifiinal I'cniix'rton method and tlio IVnil)erton method 

 niodiHe<l by tlie addition of al)ont (».r)S mj:. of snliilnu'ic acid are reitorted. Tiie 

 iimiioditied metluul pive uniformly hif^h results. Tlie modification jiave results 

 clo.sely afireeiufi with those obtained by gravimetric analysis. 



The direct determination of phosphoric acid as ammonium phosphomolyb- 

 date, E. Kabkn {Ztschr. Anali/t. Clirni., .'/7 H:>08), No. 9-10, p. r)J,G; abs. in 

 Vhrm. ZnitbL, 1908, II, No. 16, p. 1S19; Jour. C'ltem. Soc. [London^, 9', (1908), 

 No. .>).*, II, p. 896; Chcm. Ztg., 32 (1908), No. 97, Rcpcrt., p. 6'.i0).— Results are 

 reportiHl whi<-h show tliat phosithoric acid may be quite accurately determined 

 by jtrecipitating with annnonium molybdate according to Woy's method, re- 

 moving the ammonium nitrate by washing a few times with warm 70 per cent 

 alcohol, once with strong alcohol, and finally with a few cubic centimeters of 

 ether, and weighing the dried precipitate. 



The quick colorimetric determination of small amounts of water-soluble 

 phosphoric acid, I. 1'ouget and I). Chouchak (Bui. Soc. Cliim. France, J/, ser., 

 5 (1909), No. 3, pp. 10.'t-109r Vhcm. Ztg., 32 (1908), No. 70, p. 832; nh.^. in 

 Analyst, 33 (1908), No. 392, p. -}'//). — The method is based upon the intensity 

 of cloudiness produced in nitric ac-id (7 to S per cent) solution of phosphates 

 by the addition of strychnin of known strength. 



Titration of phosphoric acid in the presence of chlorids, V. liouLEZ (Chcm. 

 Ztg., 32 (1908). No. 67, />. 796; ab.^. in Chcm. Abs., 2 (1908), No. 21, p. 2917).— 

 The author claims priority for discovery of a volumetric method for the de- 

 termination of phosphoric acid in the presence of strong alcohol and chlorids. 



A simple method of determining' caustic lime, M. Popel (Zt.schr. Angcw. 

 Chcm., 21 (1908), No. .',0, p. 2080; ulj.s. in Chcm. Ztg., 32 (1908), No. 89, Rcpcrt., 

 p. 573). — A method based on distillation with ammonium chlorid, collection in 

 acid of the annuonia driven off, and titration is reconnnended. After the air 

 is driven off carbon dioxid may be determined in the residue by adding hydro- 

 chloric acid. 



On the determination of caustic lime, II. NowiCKi (Ztnchr. Angcw. Chcm., 

 21 (1908), No. .'/.7, p. 2318). — It is jjointed out that the method proposed by Ptipel 

 and noted above is inaccurate because it is based upon the assumption of the 

 indifference of calcium carbonate to -annnonium chlorid solution, whereas a very 

 large proporti(»n of the :innuonia in annnonium chlorid is shown by the author's 

 experiments to be driven off when the latter is boiled with calcium carbonate. 



Methods of water analysis, J. II. r>KEWSTER (Municipal Engin., 3-'> ( 1908), No. 

 3, pp. 162-167). — This jiaper explains brielly the possibilities and limitations 

 of analysis and sanitary survey in judging of the sanitary quality of waters, 

 and indicates the most reliable methods which have been proposed for this 

 puriio.se. 



The determination of oxyg'en consumed in waters, K M. Ciiamot (A)ncr. 

 .1(1111. I'uh. Ih/g., IS (1903), Sn. 3. pp. 2S0-28'i). — The procodin-e usi>«I in the 

 laboratory of sauilary chemistry of Cornell I'liiversity is described as follows: 



"Two hundred cubic centimeters of the sample are i)laced in a 4(H) (•<•. Krlen- 

 ineyer tlask ; lo cc. of dilute suljihuric acid (1:4) added and from a burette 

 Htundard |)otassium i)ermanganate (1 cc. =0.0001 gni. available oxygen) intro- 

 duciHl very slowly, drop by drop. As soon as a permanent pink color results 

 the burette reading is recorded, and the tlask allowe<l to stand a few minutes 

 so as to note whether decolorization will take iilace. The standard perman- 

 ganate Is again added until the total volume introduced is equal to lU cc. ; the 



