254 AUSTRALIAN NATIVE PLANTS. 
One hundred pounds of the bark yielded, in one case, 180z. 
6dr. of the oil. 
In large quantities it must be regarded as a dangerous poison. 
Rubbed externally upon the skin it does not, like myrtaceous oils, 
act as a rubefacient or irritant. 
An extract of this bark is preferred medicinally, as the essen- 
tial oil is said to have a lowering effect on the heart. The latter 
is, however, given in certain circumstances, in doses of one or two 
drops. 
Oil of Atherosperma moschata. 
Refractive Index. 
Specific 
Gravity at Rotation. 
5.5 °C! 
Temp. A D H 
1.0425 14° 1.5172 1.5274 1.5628 <7 
These determinations were made by Dr. Gladstone. The 
rotatory power was determined for a column of liquid ro inches 
long (Watts’ Dict.) 
Tasmania, Victoria and New South Wales. 
4. Backhousia citriodora, /.v.JZ., N.O., Myrtacez, B.FI., iii., 270. 
The dry leaves yield a slightly acid essential oil of specific 
gravity .887. (Staiger.) By age it becomes yellowish and resinous. 
(Bancroft.) In the report of Messrs. Schimmel & Co., Dresden, 
(Pharm. Fourn., 28th April, 1888), the following statements are 
made in regard to this oil: “Sp. gr.,.goo; boils from 223° to 
233°. Both these oils (Zucalypius Staigeriana is also referred to) 
are distinguished by an intense odour of lemon or verbena, and for 
the Backhousta oil especially, there is probably a future. The 
most important constituent of the two oils is a ketone (Cyp Hyg O ?) 
with a strong, pure, lemon odour. The oil of &. S/aigertana con- 
tains a considerable quantity of a terpene, whilst that of Back- 
