BUTYL ESTER OF BUTYRIC ACID. 467 
The barium salt thus obtained was identical in odour and 
reactions with that from the acid of the ester. Although 
the amount of salt at disposal was small, yet, sufficient 
was obtained with which to make a quantitative determin- 
ation for molecular weight. 
0°0354 gram gave 0°0264 gram BaSO, = 74°58 per cent. 
Barium butyrate gives 74°91 per cent. BaSO, 
It might reasonably be considered that as this ester is 
butyl-butyrate that both the alcohol and the acid are 
identical in form, and although sufficient acid from the 
alcohol was not available with which to prepare the calcium 
salt, yet, the odour of this acid, as well as that of its ethyl 
ester, was identical with those of the acid, and again 
corresponded with those given by pure normal butyric 
acid. 
That the greater portion of the total ester in the oil of 
EK. Perriniana is the low boiling butyl-butyrate is shown 
from the saponification results with the freshly distilled 
oil. The saponification number for the crude oil was 52°6, 
representing 13°52 per cent. of an ester having a molecular 
weight 144. The saponification number in the portion 
distilling below 190° OC. (75 per cent.) was 57°2, representing 
14°7 per cent. of ester in this fraction. The ester was not 
decomposed on direct distillation, no free acid being 
detected in the lower boiling fractions. 
In future analyses of Hucalyptus oils from trees belong- 
ing to this class, it will be necessary to determine the ester 
value in the lower boiling fractions, particularly when the 
saponification number for the crude product is at all high. 
When the identity of the ester in the oil of H. Perriniana 
from New South Wales had been determined, the amount 
of ester in the first fraction of the oil of this species from 
‘Tasmania was taken. This fraction—although investigated 
