Examination of Essential Oils. 



5 



This substance withstands a large amount of dilution without great 

 alteration in its strong absorptive power. It was examined when 

 diluted 1,000, 5,000 and 20,000 times. (Diagram 6.) 



DlAGKAM 6. 



Carraway, ceclrat, and santal wood oil give the same spectrum between -^^j and 



i 



5000" 



The ordinates represent the extent of dilution of one volume of the various oils. 

 Thickness of the layer of liquid = 15 millims. 



Cedrat Oil (Dr. Gladstone). — This substance had no constant boiling- 

 point ; it distilled between 190° and 245°, yielding a yellow vapour and 

 a thick yellow liquid, while a non- volatile yellow resin remained in 

 the retort. Examined after dilution to 1,000 and 5,000 times its 



