190 H. G. SMITH. 
the polarimeter, the rotatory angle taken, the solution evaporated 
down and allowed to absorb moisture to constant weight. From 
these results the specific rotation was found to be [a]p + 53°82. 
This sugar was a thick sweetish syrup and reduced Fehling’s 
solution. Eucalyn is described as a syrup containing one molecule 
of water, and, according to Dragendorff, has a dextro-rotatory 
power of [a], 65°. This sugar, therefore, obtained from this 
exudation, may be considered to be that previously obtained from 
Eucalyptus manna by inverting the melitose (raffinose) with dilute 
acids, and that was considered to be unfermentable, and to which 
Berthelot gave the name of Eucalyn. 
According to 0. Scheibler and H. Mittelmeier,! who have carried 
out researches on the inversion products of raffinose (or, as the 
authors name it melitriose) find that the inversion of this sugar 
by means of dilute acids takes place in two stages, in the first of 
which levulose and melibiose are produced, and that melibiose is 
the sugar previously known as eucalyn. The authors find that 
invertin acts upon their melitriose (raffinose) in a similar manner 
to dilute acids ; melibiose and levulose are first formed, the former 
being further converted by prolonged treatment with invertin into 
galactose and dextrose. Loiseau” found that raffinose was com- 
pletely fermented by the action of yeast, and Berthelot* also 
arrived at the same conclusion. 
The action of beer-yeast on the uncrystallisable sugars from 
£. punctata ceased before forty-eight hours, no further action 
taking place during the lapse of a week, the temperature during 
most of that time being under 20° ©. The eucalyn (melibiose) 
thus freed from the other sugars was separated, evaporated down, 
dissolved in water and some very active beer-yeast added; it was 
found that it slowly but entirely fermented under these conditions; 
the temperature requires to be above 20° C. the action appearing 
to entirely cease when it was as low as 18° C., but commenced 
again when increased to above 20°C. We thus see that the 
1 Ber. xx., 1678 and 3118. 2 Compt. Rend. O1x., 614. 3 Loe, cit. 
