Pflanzenchemie. — Angewandte Botanik. 365 



It is thought that Ihe specific groupings which cause the hj^dro- 

 lysis may be present in proteins or Polypeptids from preparatjons 

 possessing lipolytic activity, and a study of the lipolytic power of 

 these bodies and their decomposition products may throw light 

 upon the substances capable of causing such lipol5'-tic action. 



G. L. Foster (St. Louis). 



Falk, K. G. and M. L. Hamlin. Studies on enzyme action. 

 III. The action of manganous sulfate on castor bean 

 lipase. (Journ. Am. Chem. Soc. XXXV. p. 210 — 219. 1913.) 



Castor bean lipase Solution after being inactivated by heat was 

 rendered slightly active again by the addition of manganous sulphate. 



The foUowing explanation is offered: The enzyme is destro5^ed 

 by heat but the zymogen is not. On Standing in Solution after being 

 heated, the zymogen is changed to enzj^me by an Oxydation process 

 which is catalysed b}^ the manganous sulphate. The restored activit}' 

 of the Solution is then due to the newly formed enzyme. 



G. L. Foster (St. Louis). 



Falk, K. G., Studies on enz5''me action. V. The action of 

 neutral salts on the activity of castor bean lipase. 

 (Journ. Am. Chem. Soc. XXXV. p. 601-616. 1913.) 



The Problem involv^ed was the effect of neutral salts on the 

 activity of castor bean lipase, using ethj'l but3'^rate as the Substrate. 



In every case the change in activity, whether increase or de- 

 crease, was proportional to the concentration of the salt. All salts 

 made up of 2 univalentions decreased the activity, as did also Chlo- 

 rides and nitrates of barium, calcium, and magnesium, also sodium 

 Oxalate and dilute sodium sulfate. 



Increased activity occurred in the presence of dilute CaC)2 , 

 ßaClo, MgSO^, more concentrated Na^SO^, MnClg, and MnS04. 



The investigator suggests that the inhibiting action may be due 

 to a coagulation of the enzyme. The acceleration is unexplained 

 except in the case of manganese, where it is attributed to increased 

 formation of active lipase. G. L. Foster (St. Louis). 



Headden, W. P., Deterioration in the quality of sugar 

 beets due to the nitrates formed in the soil. (Colo. Agr. 

 Exp. Coli. Bul. CLXXXIII p. 1 — 179. 1912.) 



The author shows that neither alkalies, seepage, lack of plant 

 food, the leaf-spot disease, climatic conditions, nor insect injuries 

 can be the cause of the increasing deterioration in the quality of 

 sugar beets produced in certain parts of Colorado. It was found 

 that an application of 200—350 Ibs. of Chili saltpeter per acre gave 

 beneficial results, but that larger applications depressed the sugar 

 content of the beet as much as 33.33<^/o, increased the pure ash 

 43%, increased the nitrate content from ten to sixty-three fold , 

 depressed the phosphoric acid content about 37% ^ increased the 

 total nitrogen almost 50^/o and gave a large increase in the inju- 

 rious ash. 



The conclusion is drawn that the increased production of nitric 

 nitrogen in the Colorado soils is the chief cause for the deteriora- 

 tion of the beet. L. O. Overholts (St. Louis). 



