[Vol. 35, 1916] AGRICULTUEAL CHEMISTRY AGROTECHNY. 413 



Ceanothus velutinus (snow brush) as a source of wax and tannin, C. C. 

 ScALioNE and H. S. Blakemore {Jour. Indus, and Engin. Chem., 8 {1916), No. 5, 

 pp. ^II-J/IS, figs. 2). — C. velutinus was found to contain 7.3 per cent wax and 

 17.3 per cent of tannins. The wax was largely composed of free hydrocarbons 

 and free cerotic acid, together with palmitic and stearic acids in combination 

 with ceryl and myricyl alcohols. A trace of glycerids was also indicated. The 

 tannin was of the catecholic variety. Tanning tests have indicated that a suit- 

 able extract can be prepared from the leaves. 



Cyanogenesis in plants. Studies on Tridens flavus (tall red top), A. 

 ViEHOEVER, C. O. Johns, and C. L. Alsberg {Jour. Biol. Chem., 25 {1916), No. 1, 

 pp. 141-150). — The presence of hydrocyanic acid in the common grass T. flavus, 

 has been confirmed. Considerable quantities were present in the plants col- 

 lected in August, while only a trace was found in the plants collected in Sep- 

 tember and none in the October plants. The maximum amount of acid was 

 found in the inflorescence tops, with only a trace in the roots and none in the 

 seeds. 



No free hydrocyanic acid was obtained by direct distillation with steam. 

 Pi-evious maceration with water resulted in a loss of acid. When tartaric acid 

 was present during the maceration of the plant all of the cyanid was 

 recovered. In the presence of sodium hydroxid the loss of added cyanid was 

 complete. This loss during maceration is deemed to be probably due to a 

 chemical reaction. 



The presence of an amygdalin-hydrolyzing enzym in T. flavus was also estab- 

 lished. 



The separation of autogenous and added hydrocyanic acid from certain 

 plant tissues and its disappearance during raaceration, C. L. Ajlsberg and 

 O, F, Black {Jour. Biol. Chem., 25 {1916), No. 1, pp. 133-1^0) .—It has been 

 shown that "the leavfes of Primus virginiana must be distilled with acid four 

 hours before all of the hydrocyanic gas is liberated, whereas in Andropogon 

 and Panicularia less than one hour is sufficient to liberate all hydrocyanic acid 

 present." 



When plant tissues which contain hydrocyanic acid, or to which cyanid has 

 been added, are macerated a certain portion of the hydrocyanic acid is con- 

 verted into such form as not to be recoverable by distillation with sulphuric 

 acid. This is not due to the action of enzyms or to the presence of glucose. 

 It is indicated that in determining the hydrocyanic acid in plants several 

 methods in corroboration of one another should be used. 



The distribution of maltase in plants. — I, The function of maltase in 

 starch degradation and its influence on the amyloclastic activity of plant 

 materials, W. A. Davis {Biochem. Jour., 10 {1916), No. 1, pp. 31-48, figs. 2).— 

 It is indicated that maltase is probably present in all plants in which starch 

 degradation occurs. The facts that the enzym is endocellular and therefore 

 not easily extracted and is also imstable account for the failure of earlier 

 workers to detect the presence of the enzym generally. The action of the 

 enzym is greatly inhibited or even destroyed at temperatures above 50° C. and 

 is destroyed by ordinary alcohol or chloroform. 



Maltase occurs in considerable quantities in germinated and ungerminated 

 cereals, and is probably localized mainly in the aleurone layer of the endosperm. 

 If the kilning has been at a temperature sufnciently low not to destroy the 

 enzym it may be present in malt. Its presence in malt or malt diastases would 

 explain the formation of glucose from starch, which has previously been 

 attributed to other causes. Maltase of plants does not act directly on starch 

 or dextrins, but only on maltose which has been formed by diastatic enzyms. 



