AGRICULTURAL CHEMISTRY AGROTECHNY. 107 



(E. S. R., 21, p. 710), and tho filtrate treated in the usual manner for deter- 

 mining potash. 



The estimation of potassium as potassium, platinic chlorid, H. Fresenius 

 iOsterr. Chcm. Ztg., 13 {1910), No. 2J,. pp. 30^, 305).— The author sought to 

 determine the influence whicli various salts exert upon the results of the esti- 

 mation of potassium as potassium platinic chlorid in a solution of potassium 

 chlorid. 



The work shows that where much calcium chlorid is present with potassium 

 chlorid and sodium chlorid. and is not previously removed, the results for potas- 

 sium are high. The same was found to be the case for potassium in admixture 

 with sodium, magnesium, and barium chlorids. 



The tests made to determine the proper strength of alcohol for this work 

 showed that 70 per cent alcohol gave low results and 85 per cent high results, 

 while 95 per cent alcohol gave good results for the potassium oxid but with 

 evidences of a possibility of reducing the sodium chlorid to the oxid state. A 

 concentration of SO per cent alcohol is deemed the best. 



Estimation of phosphoric acid by direct weighing of the ammonium phos- 

 pho-molybdate, N. von Lorenz {Ontcn: Chein. Ztg., Iff {1911), No. 1, pp. 

 l-o). — This article deals with the question of the priority of this method 

 (E. S. Ii., 13, p. 14) and criticizes Jorgensen's findings with a similar method 

 (E. S. R., 19, p. 506). The method is again described in detail and its appli- 

 cation for slag, soils, and ashes is discussed. 



The titrametric estimation of phosphorus in small amounts, L. T. Bowser 

 {Amer. Cliem. Jour., J,5 {1911), No. 3, pp. 230-237).— ''The method, briefly 

 stated, is as follows: Use a convenient volume of solution, but see that when 

 ready for precipitation it is not less than 20 cc. For less than 0.8 mg. P2O5 use 

 1 cc. molybdate solution, for more 1.5 cc. and 0.5 gm. ammonium nitrate, pre- 

 cipitate at 55° C, keep for 1 hour at that temperature, let stand for 2 hours, 

 filter and wash. Titrate with a standard hydroxid solution not stronger than 

 0.02 N." 



Determination of the basicity of Thomas slag- powder, R. Michel {Chem. 

 Ztg., 34 {1910), No. 93, p. S30; ahfi. in Chcm. Ahs., 5 {1911), No. 1, p. 51).— The 

 author proposes heating 1 gm. of the powder with about 15 cc. of 20 per cent 

 ammonium niti'ate solution In a 200-cc. round-bottom flask. The anmioiiia is 

 then driven off by means of air which has been previously passed through sul- 

 phuric acid, and which is allowed to bubble through the mixture for three- 

 quarters of an hour. The ammonia is caught hi an excess of tenth-normal acid 

 solution. A blank experiment conducted without slag powder liberated no 

 ammonia. 



Biochemical handbook, edited by E. Abdebhalden {Biocliemifiches Hand- 

 lexikon. Berlin, 1911, vol. 5, pp. VI+Gl'-'i). — This volume treats of the alka- 

 loids, animal poisons, products of internal secretions, antigens, and ferments. 



Action of the metallic salts of the gold group upon the saccharification 

 of starch by the amylolytic ferments, C. Gerbee {C'ompt. Rend. Soc. Biol. 

 [Paris], 70 {1911), No. J/, pp. 139-l.'i5). — Cadmium, chlorid, zinc chlorid and sul- 

 phate, silver nitrate, and mercuric chlorid were studied in regard to their effect 

 upon the action of starch ferments. 



A glucosid from Tephrosia purpurea, G. Clarke, Jr. and S. C. Banerjee 

 {J&iir. Chem. Soo. [Lqndon~\, 97 (1910), No. 575, pp. 1833-1837; abs. in Zentbl. 

 Biochem. u. Biophys., 11 (li910). No. 1, p. 8). — From an alcoholic solution or 

 extract of this legume, the authors isolated a glucosid which on hydrolysis 

 yields quercetin, rhamnose, and glucose, and possesses the formula C\7H3oOi8+ 

 3H.0, 



98334°— No. 2—11 2 



