[Vol. 36, 1917] AGRICULTURAL CHEMISTRY — AGROTECHNY. 13 



Experiments upon the amylase of Aspergilltis oryzee, H. C. Sheeman and 

 A. P. Tanbeeg {Jour. Amer. Chem. Soc, 38 {1916), No. 8, pp. 1638-1645).— From 

 the study reported, the object of which was to purify the amylase as far as 

 practicable and to compare its nature and properties with those of the pan- 

 creatic and malt amylases, it was found that the amylase of A. oryzce exerts its 

 maximum activity in a very slightly acid medium. Acid phosphate accelerates 

 the action, while alkaline phosphate retards it. "Addition of neutral electrolytes, 

 such as sodium and potassium chlorids, to commercial taka-diastase has no 

 measurable effect upon the saccharogenic power, but does increase the amylo- 

 clastic action." 



The best preparations were obtained by extracting with water, precipitating 

 with ammonium sulphate, dialyzing, and finally precipitating fractionally 

 with alcohol. Such preparations are about thirty times as active as the com- 

 mercial material from which they are prepared, but are not so active as the 

 purified pancreatic amylase. 



" The purified material resembled the preparations of pancreatic and malt 

 amylases in most of its chemical properties. It gave typical protein reactions 

 when submitted to the Millon, xanthoproteic, tryptophan, and biuret tests. 

 Heated in water solution it underwent coagulation, and the coagulum and 

 filtrate both showed the biuret reaction, the color being considerably pinker in 

 the case of the filtrate than with either the coagulum or the original material. 

 That its nitrogen content was lower than that of the best preparations of pan- 

 creatic and malt amylases may be due either to a difference in the chemical 

 nature of the enzym Itself or to the presence of other substances which the 

 methods of purification thus far developed do not wholly remove." 



Researches on the enzyms of the blood in the albumin and globulin frac- 

 tions of the serum, G. Satta {Arch. Ital. Biol., 64 {1915), No. 1, pp. 118-122).— 

 It is shown, by separating the blood serum into its albumin and globulin frac- 

 tions, that the tributyrinase, amylase, and glycyltyrosinase of the blood serum 

 exist exclusively in the albumin fraction. 



A nonspattering wash bottle, F. C. Clapp {Jour. Amer. Chem. Soc, 38 

 {1916), No. 8, pp. 1502, 1508, fig. i).— The author, at the Minnesota Experiment 

 Station, describes a wash bottle so constructed as to obviate spattering at the 

 tip of the nozzle. The principle of raising the water table of the wash bottle 

 slightly above the level of the tip of the nozzle has been adopted in its con- 

 struction. " Back action " is thus avoided and the nozzle tube is kept perma- 

 nently full of water. 



Researches on quinazolins. — XXXIII, A new and sensitive indicator for 

 acidimetry and alkalimetry, and for the determination of hydrogen-ion con- 

 centrations between the limits of 6 and 8 on the Sorensen scale, M. T. Bogebt 

 and G. Scatchabd {Jour. Amer. Chem. Soc, 38 {1916), No. 8, pp. 1606-1615).— 

 The authors describe the preparation and use of a dinitrobenzoylene urea, the 

 monosodium salt of which is a very sensitive indicator for hydrogen-ion concen- 

 trations between the limits of 6 and 8 on the Sorensen scale, changing from 

 colorless to greenish yellow. It resembles p-nitrophenol more closely than any 

 of the other well-known indicators. The chief disadvantage of its use is its 

 yellow color, which renders it unsuitable for work by artificial light. The indi- 

 cator is but slightly affected by neutral salts and proteins, and not at all by 

 chloroform or toluene. Its color fades very slightly in about a week, but is 

 unaffected by nitrous acid. It can be used in either cold or boiling solutions. 

 A sharp end point is obtained with ammonium hydroxid and hydrochloric acid, 

 but it is unsuitable for use in titrating carbonates. 



The opinion is expressed that in the preparation of neutral ammonium citrate 

 for fertilizer or soil analysis it should prove superior to rosolic acid. 



