Examination of Essential Oils. 



25 



Oil of Bitter Almonds (Dr. Piesse). — Solutions in 1,000, 5,000, 

 10,000, 50,000, and 100,000 volumes of alcohol were examined. 



A highly characteristic absorption distinguishes this substance. 

 As is well known, it is the aldehyde of benzoic acid. (See Diagram 24.) 



Diagram 25. 



Oil of peppermint. B.P. 198—215°. (Dr. Gladstone.) 



500001 



Oil of Peppermint (Dr. Gladstone). B.P. 198— 215°.— This is ob- 

 tained by distilling Mentha piperita. Dr. Gladstone states that both 

 the English and Italian specimens examined by him contained a 

 hydrocarbon which has physical properties differing little from those 

 of the hydrocarbon from bay. It will be seen, however, that the 

 absorption spectra due to these two substances are very different. 



The following is a summary of our conclusions with regard to the 

 ter penes : — 



1. Terpenes, with the composition C 10 H 16 , possess in a high degree 



