252 ODOKOGRAPHIA. 



It is reported that the firm James liobertson & Co., of 

 Melbourne, has devoted itself with great energy to the preparation 

 of Eucalyptus oil, and has erected a factory on Lake Hindmarck 

 (Victoria), not far from the railway that passes from Melbourne to 

 Adelaide, and will principally confine itself to the preparation of 

 oils with a high percentage of Cineol. The firm believes that the 

 conditions on the banks of the above-named lake are more favourable 

 than anywhere else, and will especially attend to the distillation of 

 E. cncorifolia, E. gracilis, E. uncinata and E. incrassata. 



The manner of estimating such oils as the above (and many 

 others), by the percentage of Cineol (eucalyptol) is absolutely 

 necessary, because it is impracticable (as is admitted at the sources 

 of production) to successfully maintain a distinction between the 

 differents sorts of material. 



E. amygdalina, the " Xarrow^-leaved peppermint tree," also 

 called the " Brown or AVhite Peppermint tree of Victoria." It is 

 found in south-eastern South Australia, throughout Tasmania and 

 Victoria, and in the extreme south of Xew South Wales. This is 

 another tree of colossal dimensions, generally attaining a height of 

 150 feet, with a trunk sometimes 8 feet in diameter at the surface 

 of the earth; some old trees have been found of 480 in height with 

 a trunk 81 feet in circumference at 4 feet from the earth. Such 

 trees only commence to branch out at a height of 295 feet. (The 

 Wellingtonia gigantea, of California, is the only tree rivalling it in 

 size). 



The yield of essential oil from fresh leaves of E. amygdalina has 

 been estimated at from 2 to 4 per cent.* Mueller f states the 

 yield to be 313 per cent. Staiger says the leaves yield 1,250 

 ounces per ton. 



Its sp. gr. is 0-86 to 0-89 at 15^ C. It boils practically between 

 170^ and 180^ C, and is laevogyre. Observations on three 

 different samples gave, in a hundred m.m. column, a rotatory 

 power of — 27^, — 28° and — 28^6'; consequently this property 

 allows of it being easily distinguished from the dextrogyre oil 

 of E. glohulus. 



* Kaveret-Wattel, L'Eucalyptus, sa culture, proprietes, etc., Paris, chez la 

 Librairie centrale d' Agriculture, p. 26. 



t Select extra tropical plants, p. 146. 



