48 EIGHTH REPORT — 1838. 



the first time in Cumberland at Caldbeck fell. The author's spe- 

 cimen of this mineral exhibits a deposit of yellow.phosphate of lead 

 upon another side of the mass of quartz, upon which the diarseniate 

 has been deposited. 



On Emulsin. By Dr. T. Thomson and T. Richardson. 



Some years ago Robiquet and Boutron CharlaM showed that volatile 

 oils of bitter almonds and prussic acid, which are obtained by the di- 

 stillation of bitter almonds, do not exist naturally in almonds but re- 

 sult from the pi'ocess. They further ascertained that when milk of 

 bitter almonds, formed by triturating almonds with water in a mortar, 

 is treated with strong boiling alcohol, white crystals are deposited, on 

 cooling, which separate in larger quantity by concentration. To this 

 substance they gave the name of Amygdalin. Liebig and Wiihler have 

 determined this body to be an amide of amygdalic acid, represented 

 by the following formula : 



Subsequently, the investigation was continued by Wohler and Liebig, 

 who observed that when a solution of amygdalin is brought in contact 

 with a milk of sweet almonds, a most remarkable and peculiar action 

 takes place ; prussic acid and oil of bitter almonds are foi'med, as in 

 the instance already mentioned. When milk of bitter almonds is distilled 

 without the artificial addition of amygdalin, besides prussic acid and 

 oil of bitter almonds, there is also formed sugar, which may be de- 

 composed by fermentation. The solution after the termination of the 

 fermenting process affords a strong acid reaction which is not produced 

 by acetic acid or any other volatile acid. When alcohol is added and 

 the solution concentrated, thick white flocks are precipitated which 

 obviously contain no emulsin, because when dissolved in water they 

 have no action upon amygdalin. From these properties the flocks 

 would appear to be gum. 



The phenomena exhibited in the reaction described, which have 

 been termed Catalytic by Berzelius, resemble in a great measure those 

 which take place in fermentation ; and their investigation promises to 

 throw great light upon some of the most important processes of the 

 vegetable and animal ceconomy. With the view of assisting in the 

 elucidation of the subject, the authors have commenced with the ex- 

 amination of the essential ingredient of the milk of sweet almonds which 

 has been termed emidsin. 



The process by which this substance was obtained was as follows. 

 Sweet almonds were triturated in a mortar and small portions of water 

 were gradually added until a milky fluid was obtained. This fluid wa5 

 mixed with four times its volume of ether and frequently agitated so 

 as to eff"ect an intimate mixture. A clear fluid gradually separated at 

 the bottom of the stoppered bottle in which the experiment was made, 

 which in the course of three weeks was drawn off by means of a syphon. 

 This fluid was passed through a filter, and to one-half of the clear so- 



