408 EXPERIMENT STATION RECORD, 



Contrary to the findings of Gentlie the author obtained complete oxidation 

 in 45 hours in ultraviolet rays. A lead-manganese rosin compound containing 

 6.28 per cent lead and 5.76 per cent manganese was found to be the most active 

 agent for hastening oxidation. 



Soy-bean oil is readily polymerized, though not to so great a degree as lin- 

 seed oil. On heating the oil at 150° in an air bath the iodin number was found 

 to have decreased from 137.5 to -90.5, while the molecular weight remained 

 constant and the oil liquid. Higher temperatures gave no better results. By 

 adding 30 per cent of linolic acid to the oil and heating to 2.50° the iodin num- 

 bers were reduced but the oil remained liquid. Heating the oil at 300° for 

 12 days caused it to become solid, and after 17 days to become insoluble in 

 benzene. The molecular weight of a sample heated for 10 days at 300° rose to 

 1,200. Adding 1 per cent oxidized soy-bean oil to fresh oil and heating to 300" 

 caused the mass to become solid in 7 days. 



The isomeric tetracetates of xylose, and observations regarding the ace- 

 tates of melibiose, trehalose, and sucrose, C. S. Hudson and J. :M. Johnson 

 (Jour. Amcr. Chcm. Soc, 37 (1015), Xo. 12, pp. 2748-2753). 



Bromoacetylxylose and beta-triacetylmethylxylosid, J. K. Dalk {.lour. 

 Amcr. Chcm. Soc, 37 (1915), Xo. 12, pp. 27. ',5 27^7). 



The preparation of melibiose, C. S. Hud.son and T. S. Harding (-lour. Amer. 

 Chcm. Soc, 37 (1915), No. 12, pp. 2754-2756).— Following the main lines of 

 Loiseau's method uniform yields of from 175 to 200 gm. of melibiose were ob- 

 tained from 500 gm. of pure raffinose (E. S. R., 32, p. 711). The product was 

 colorless and gave a correct value for its specific rotation. 



A second crystallin 5-fructose pentacetate (a-5-fructose pentacetate). C. S. 

 Hudson and D. H. Brauns (Jour. Amcr. Chcm. Soc, 37 (1915), Xo. 12, pp. 2736- 

 27.',5). 



The effect of sodium chlorid upon the action of invertase, II. A. Fai.es and 

 J. M. Nelson (Jour. Amcr. Chcm. Soc, 37 (1915), Xo. 12, pp. 2769-27S6, figs. 

 4). — The experimental data indicate that the hydrogen ion concentration re- 

 mains constant throughout the whole course of the inversion of cane sugar by 

 invertase. 



"At the optimum of invertase action, the .salt effect of the sodium chlorid 

 seems to approach zero, and as we depart eitlier side from the optimum we get 

 an increasing salt effect. The use of buffers (tampons) for reguhiting the con- 

 centration of hydrogen ion introduces a certain salt effect. The most satisfactory 

 region for using buffers in invertase velocity measurements is in the neighbor- 

 hood of tlie optimum zone where the salt effect is a minimum. In the region 

 of enzym activity it is necessary to measure the concentration of hydrogen ion, 

 and it is not permissible to calculate it from the molarity of acid usetl. The 

 addition of sodium chlorid to solutions of hydrochloric acid causes an increase 

 in the concentration of hydrogen ion as measured by the electromotive force 

 method and by tlie hydrolysis of cane-sugar solutions." 



Acid potassium and acid sodium phthalates as standards in acidimetry 

 and alkalimetry, W. S. Hendrixson (Jour. Amcr. Chcm. Soc, 37 (1915), Xo. 

 10, pp. 2352-2359). — The salts have been applied as acidimetry and allvalimetry 

 standards. It has been observed by the author that " the results obtainetl by 

 using silver, benzoic acid, and the two acid phthalates as standards are almost 

 identical. So far as the results go they indicate that one of the organic stand- 

 ards is as good as another in point of accuracy. The acid phthalates have some 

 advantage in their much higher molecular weights, their greater solubility, and 

 the fact that they can be prepared pure and true to the formulas accepted for 

 the anhydrous salts without the use of unusual and time-consuming methods of 

 purification." 



