— ig — 



their comparatively ready solubility in water. Here also the physical 

 and chemical constants were in close agreement, only the benzalde- 

 hyde-content varied from 61,8 to 88,7 °/ , and, except in the case of 

 an oil distilled from plum kernels, which had 88,7 °/ of aldehyde, re- 

 mained below the minimum content of 85 °/ required by the Phar- 

 macopoeia. This low content Rabak also attributed to the fact that 

 the quantities used were too small and were readily liable to oxidation. 

 According to an estimate, the total annual production of kernels in 

 the State of California and of the oil which might be prepared from 

 them, would be as follows: — 



Kernels Pressed oil Essential oil 



Apricots 5000 tons 400 to 500 tons 18000 to 22000 lbs. 



Peaches 10 000 „ 210 „ 420 „ 7800 „ 15600 „ 



In conclusion, Rabak calls the attention of fruit growers in the 

 United States to the fact that, instead of throwing away the stones or 

 using them as fuel, as at present, they might with greater advantage 

 use them for the production of these valuable "oils. 



A continuation of the paper discussed in our previous Report 1 ) is 

 supplied by the second treatise of L. Rosenthaler 2 ) on asymmetric 

 syntheses produced by enzymes. The author has investigated the 

 effect of foreign bodies upon the rotation, which occurs in the benz- 

 aldehyde-hydrocyanic acid-emulsin system. In every experiment he 

 diluted equal parts of benzaldehyde, hydrocyanic acid, and emulsin 

 with alcohol, formaldehyde, metallic salts, and so forth, and compared 

 the rotation observed unther these conditions with that shown by the 

 same quantities of experimental material minus the added foreign 

 bodies, but under otherwise equal conditions. The following, generally 

 speaking, had but a slight deteriorating effect (i. e. did not greatly 

 reduce the altitude of rotation) viz., alcohol (even if added in com- 

 paratively large proportions), 1 °/ phenol-solution, formaldehyde, am- 

 monium sulphate, magnesium sulphate, hydrogen sulphide, manganese 

 sulphate, and hydrogen ferrocyanide. On the other hand, the following 

 produced deteriorating results, viz., sulphate of copper, acetate of lead 

 and oxide of mercury, as well as H- and OH -ions. In fact, OH -ions 

 entirely prevent the generation of optically active substances, whereas 

 H-ions only act injuriously. Pepsin and trypsin are injurious in neu- 

 tral solution. Further, s- emulsin 3 ) is precipitated by picric and tannic 

 acids. From these experiments, Rosenthaler concludes that, on the 

 whole, s-emulsin behaves like an albumen, by which, however, he must not 



*) Report April 1909, 17. 



*) Biochemische Zeitschr. 1909, 257. From a reprint kindly sent to us. 

 8 ) The constituent of emulsin which influences the synthesis, Rosenthaler 

 calls syn- (s-) emulsin; that which hydrolyses he calls dia- (d-) emulsin. 



