272 R. T. BAKER AND H. G. SMITH. 
From these results we are enabled to make the following 
announcements, and what is true of the oil of this tree we consider 
to be true of any species of this class of Eucalypt, because we are 
slowly obtaining evidence that the Eucalypts are divisible into 
classes as regards their oil and its quality, as well as into classes 
based on the composition of their kinos, or by their anthers. 
1. Optical rotation of the oils.—The action these oils have on a 
ray of light is not constant, except the leaves be taken from one 
tree. We find that both dextro-rotatory and levo-rotatory oils 
are obtained from trees growing near each other and in the same 
soil. The specific rotation varies from [a],+0°54° to +4:44° 
and from —0-92° to —2-52°. The rotation was dextro-rotatory 
in most cases, but the activity was not great in any case. It was 
also found that when the original oil was dextro-rotatory, that 
the first two fractions were also dextro-rotatory, and that when 
the original oil was levo-rotatory that the first two fractions were 
also levo-rotatory, and that the increased rotation of the first 
fraction was that of the original oil, whether levo- or dextro- 
rotatory. The readings were taken in a 200 mm. tube and the 
temperature was near 17° ©. The determinations were usually 
made two days after the oil had been obtained. Although the 
oil from the leaves of each individual tree has the same rotation, 
yet, owing to the want of constancy in the rotation of oil from 
several trees as experienced by us in these determinations, we are 
forced to admit that the specific rotation is not of much value 
except for scientific investigation. 
2. Specific gravity of the oils.—The specific gravity of the 
several oils is not constant, except when obtained from leaves 
growing on the same tree. We distilled oil from a fine tree in 
two separate parcels, and we found the specific gravity of the oil 
to be ‘9122 in both cases. The oil from another fine tree had 4 
specific gravity -9192, while that of another was -9205. The 
specific gravity of the oils from various trees not kept separate 
was about ‘9165, while that obtained by mixing together equal 
volumes of the oils investigated, was found to be ‘9153. The oil 
