This section is from the book "The Volatile Oils Vol2", by E. Gildemeister. Also available from Amazon: The Volatile Oils.
The aloe plant owes its faint but characteristic odor to a very small amount of volatile oil.
Upon the distillation of 500 lbs. of Barbadoes aloes (from Aloe vulgaris, Lam.; A. barbadensis, Mill.; A. vera, L, family Liliaceae), T. & H. Smith & Co., London, obtained 2 fld. dr. of aloe oil. It is a light yellow, mobile liquid, sp. gr. 0,863, and boils between 266 and 271°2).
 
Continue to: