On the Crystalline Deposit from Oil of Bitter Almonds. 27 

 1*1711 grm. salt gave 0-5516 silver. 



100-000 100-000 



Prom these results it is clear that the cr3^stalline deposits from 

 oil of bitter almonds examined by me were simply benzoic acid, 

 and this I have reason to believe was also the case with two out 

 of the three samples described by Dr. Pereira ; for through the 

 kindness of Professor Redwood I obtained three small specimens 

 of these deposits from Dr. Pereira's collection, now in the pos- 

 session of the Pharmaceutical Society. That marked No. 1 

 I found to be simply benzoic acid. I received also a specimen 

 given to the Pharmaceutical Society by Mr. ^'VTiipple; it was 

 also benzoic acid. The specimen marked No. 3, and which 

 amounted only to a few grains in weight, was that examined by 

 Drs. Pereira and Letheby. It consisted of small, acicular, 

 lemon-yellow crystals, which were insoluble in water, alcohol, 

 aether and acetic acid. Sulphuric acid reddened and then dis- 

 solved them, forming a deep yellow solution. They were not 

 dissolved by a solution of caustic potassa in the cold ; when 

 heated with it, however, ammonia was evolved, which proved 

 that the ci-ystals contained nitrogen. When the crystals were 

 strongly heated on platinum foil they melted and were decom- 

 posed, a small amount of sublimate only being produced. 



The origin of the crystalline deposit No. 3 is very obscure. 

 Mr. Whipple informs me that he only obtained it on one occa- 

 sion, many years ago, when the essential oil of almonds was 

 prepared by distillation over the naked fire ; but ever since the 

 operation has been eflfected by means of a steam apparatus, he 

 has never met with it again, and has merely obtained deposits 

 of benzoic acid. I strongly suspect that the yellow insoluble 

 crystals marked No. 3 were pi'oduced by the action of ammonia 

 on oil of bitter almonds, and that the aminonia on that occasion 

 was probably evolved by the charring of a portion of the nitro- 

 genous pulp of the almonds by the overheating of the bottom of 

 the retort. The crystalline deposits which form in oil of bitter 

 almonds must be regarded therefore (unless in the single some- 

 what inexplicable instance just stated) as simply benzoic acid 

 resulting froni the oxidation of the oil. 



