AGRICULTURAL CHEMISTRY AGROTECHNY. 609 



Takadiastase, J. Wohlgemuth (Biochem. Ztschr., 39 {1912), No. S-4, pp. 

 S2^S8; abs. in Jour. Chem. 8oc. [London], 102 (1912), No. 595, I, p. 402).— 

 The amylase of takadiastase required a stronger concentration of acid to pro- 

 duce a corresponding inhibition of its action upon starch than did the amylase 

 contained in the saliva. Like other amylases, it is sensitive to alkalis, but less 

 so than salivary amylase. The amylolytic action of takadiastase was stimu- 

 lated by the presence of salts in a concentration of tenth-normal, but not by 

 lower concentrations. Takadiastase also possesses marked coagulating, chymo- 

 sin-like, lypolytic, and tryptic powers, but no peptolytic power. It also contains 

 an adrenalase. 



A color reaction of am.inonia, P. Thomas (Bui. 8oc. Chim. France, .'}. ser., 

 11 (1912), No. 15, pp. 796-799; abs. in Jour. Soc. Chem. Indus., 31 (1912), No. 16, 

 p. 771). — The reaction studied was first noted by Berthelot in 1859, and may 

 be used as a quantitative method in the following form : " Into a series of test 

 tubes are measured known quantities, 5 cc. down to 0.1 cc. of a 1 in 10,000 

 solution of ammonium chlorid, the volumes made up to 5 cc, then 1 cc. of a 

 4 per cent solution of phenol added, and finally 1 cc. of a dilute solution of 

 sodium hypochlorite. On mixing, a blue color develops. The solution in which 

 the ammonia is to be estimated is treated in the same way, and the two colors 

 compared. The sensitiveness is equal to that of the Nessler test. The reaction 

 is also given strongly by glycocoll and some of the primary amins." 



Notes in regard to the titration of phosphoric and boric acids, W. Biltz 

 and E. Marcus (Ztschr. Anorgan. Chem., 77 (1912), No. 1, pp. 131-136) .—If 

 phosphoric and boric acids are to be determined in the same solution and in the 

 presence of magnesium chlorid, the solution must first be neutralized against 

 methyl orange and titrated with a decinormal solution of sodium hydroxid. 

 using phenolphthalein as the indicator. Mannitol is then added and the solu- 

 tion again titrated with sodium hydrate solution, this last titration representing 

 the boric acid. 



Another method consists in making the solution neutral against phenolphtha- 

 lein as before, then adding mannitol, and titrating with sodium hydroxid. 

 Both acids thus titrated behave as monobasic acids. The titration can also be 

 made in the presence of calcium chlorid, but allowance must be made for the 

 tertiary calcium salt produced which acts as a tribasic acid. 



Gerhardt's statement that free phosphoric acid remains In solution when 

 shaken with calcium carbonate is contradicted. 



Determination of potassium, especially in fertilizers, soil extracts, and 

 plant ashes, W. A. Davis (Jour. Agr. Sci. [England], 5 (1912), No. 1, pp. 

 52-66; abs. in Jour. Soc. Chem. Indus., 31 (1912), No. 21, p. 1045).— The per- 

 chlorate method is considered simpler and more exact than the platinic chlorid 

 method. 



" An improvement consists in washing the precipitate of potassium perchlorate 

 with 95 per cent alcohol saturated at the temperature of working with potassium 

 perchlorate. This allows thorough washing and obviates any error due to the 

 solubility of the precipitate. The economy of the new method is a very real 

 advantage. The presence of barium, magnesium, and calcium chlorids and 

 sodium phosphate is without prejudice and these salts need not be removed. 

 With a sufiicient excess of perchloric acid, potassium sulphate can be estimated 

 directly without conversion into chlorid ; alternatively when the sulphate is 

 converted into chlorid by the Stassfurt method, the exact precipitation of the 

 sulphate is not imperative. The method also avoids the uncertainty attaching 

 to the atomic weight of platinum." 



Estimation of lime in plant ashes, P. L. Gile and C. N. Aqeton (Porto Rico 

 Sta. Rpt. 1912, pp. 21, 22). — In connection with investigations on the effects of 



