— 17 — 



ft 68.— to c/M 70. — per 100 kilos, the Japanese shippers have taken ad- 

 Mntage of the position by placing upon the market considerable quantities 

 of excellent quality. These apricot kernels come decidedly cheaper than 

 the Syrian, and we have therefore taken the opportunity of covering our 

 principal requirements from the new source of supply. It will probably 

 .appear in the course of the next few months whether, in spite of this, 

 the demand for Syrian apricot kernels on the part of the confectioners 

 will be strong enough to keep up the prices, or whether the holders will 

 be compelled to show themselves more tractable. Californian apricot 

 kernels are this season once more too dear to make it possible to con- 

 sider them for our purposes. As is well known, our plant for pressing 

 almond oil is on the largest scale, and we are able to compete success- 

 fully with all fair-dealing competitors as regards prices, both for almond 

 oil pressed from apricot kernels and for essential oil of bitter almonds. 



The results of Feist's investigations 1 ) described in our previous Report 

 pointed to the primary generation of d-benzaldehyde cyanohydrin when 

 amygdalin is split up. But L. Rosenthaler 2 ) is of opinion that no proof 

 whatever has been given of this primary occurrence of d-benzaldehyde 

 cyanohydrin. On the contrary, he has succeeded in demonstrating that 

 d-benzaldehyde cyanohydrin is generated secondarily in the amygdalin- 

 emulsin system, for he was able to ascertain by experiment that when 

 amygdalin is split up with emulsin, hydrocyanic acid is formed within at 

 most two minutes. It follows, as benzaldehyde is also formed in the 

 course of this reaction, that d-benzaldehyde cyanohydrin must be generated 

 immediately, all the determining factors for this result being present, while 

 every circumstance which might prevent the generation is absent. Rosen- 

 thaler also proved that the specific rotation of the nitrile isolated from 

 the amygdalin -emulsin system rises proportionately to the quantity of 

 the emulsin employed, which affords additional proof for the generation 

 of secondary d-benzaldehyde cyanohydrin. 



On the other hand, two other experiments showed the probability of 

 the primary generation of d-benzaldehyde cyanohydrin. To the mixture 

 of amygdalin and emulsin there was added a substance which combines 

 with hydrocyanic acid immediately upon the liberation of the last-named 

 body. Nickel formate was employed for this purpose. Nevertheless, after 

 the reaction had proceeded three hours, a dextrorotatory nitrile had been 

 formed. Amygdalin was also split up with an emulsin which had been 

 treated with copper sulphate, and in which, therefore, only the ^-portion 3 ) 

 was present. In the presence of this enzyme also, of which the action 

 was only a hydrolysing one, d-benzaldehyde cyanohydrin was formed. 



*) Arch, der Pharm. 247 (1909), 542; Report April 1910, 17. 

 2 ) Arch, der Pharm. 248 (1910), 105. 

 -) Comp. Report October 1909, 19. 



