114 Hoh'iquet on Aroma. 



the almonds with a certain quantity of ammonia or its elements, 

 and the following is the reason for my opinion. It will, without 

 doubt, have been remarked, that I did not obtain any of this 

 supposed essential oil on distilling the recent juice of the 

 apricot kernel, whilst this same juice, distilled with calcined 

 magnesia, furnished a considerable quantity. It results also 

 from Ihe experiments of M. Vogel, that this volatile product, 

 exposed to the air, concretes, crystallizes, becomes inodorous, 

 and does not volatilize. He attributes these phscnomena to 

 the absorption of oxygen, but I regard them as occasioned by 

 the loss of ammonia. Finally, it is known that the essential 

 oils have a strong affinity for the fixed oils, and it is not evident 

 why these two products do not mix when bitter almonds are 

 submitted to strong pressure, though such mixture does not 

 take place if heat is not made use of, as M. Planche has de- 

 monstrated, and I have had occasion to verify the fact. I have 

 obtained an oil from bitter almonds as inodorous and tasteless 

 as that obtained by the same means from sweet almonds ; but 

 if the plates be slightly heated, as is generally the case, then 

 the combination is effected, and the oil is odorous. I do not 

 think that a doubt can be entertained, after what has been 

 stated, that the odour contracted by the juice of the kernels 

 by the assistance of time, is not really due to the developement 

 of ammonia. But is the odour the result of an intimate com- 

 bination of the essential oil with the ammonia, or should the 

 ammonia be considered as furnishing a convenient vehicle for 

 its developement ? This I cannot explain at present, but I hope, 

 nevertheless, to succeed in resolving the question. 



It is possible, that, notwithstanding what I have said, no 

 difficulty may be found in admitting the continued formation 

 of prussic acid, and attributing the odour so strongly indicated 

 to the presence of this acid : I will oppose the following expe- 

 riment to those who may hold such an opinion : I took a cer- 

 tain quantity of the juice of the kernels of apricots that had 

 been prepared several days, and were very odorous. I put it 

 into a tube with powdered red oxide of mercury, and agitated 

 it many times, but did not perceive the slightest change in the 



