1908. | Studies on Enzyme Action. 319 
carried out, side by side, with the two kinds of raffinose and with cane-sugar ; 
moreover, with the object of ascertaining the effect of further purification on 
the stability of the sugar in presence of the enzyme, the recrystallised 
raffinose was dissolved in “conductivity ” water, the solution was mixed with 
alcohol and a stream of carbon dioxide passed through it during 50 minutes, 
this artifice having been found to be of service in purifying galactose; the 
solution was then filtered and a large bulk of alcohol added to the filtrate. 
The material obtained by this method is the “ Raffinose III” in the 
following table. It was again recrystallised from a mixture of alcohol and 
“conductivity ’ water; the material thus obtained is marked “ Raffinose IV.” 
Equimolecular proportions of these samples of raftinose having been dissolved, 
the liquids were boiled to drive off any alcohol present, and were then diluted 
to the proper volume. Equal volumes of these solutions were measured out 
and to each was added the same number of cubic centimetres of a dilute 
invertase solution. The results are recorded in Table V. 
Table V. 
Amount hydrolysed at 25°. | 
1 hour. 2 hours. 3 hours. 4 hours. | 
Per cent. Per cent. | Per cent. Per cent. 
WRMICHB ISAT. Scras<aclnte nas sss oe 96 °2 — | — — 
Kahlbaum’s raffinose......... 42 °7 65 °8 80 °3 88 °8 
Recrystallised raffinose ...... 38 ‘1 GE-9 76 °4: 82 °8 
RMatinose LTT octet eee ees 38 °4 60 °8 76°9 82-9 
PAEMOSCTE Vo ee esc ee veces 37 *4 59 °2 76 °2 84 °5 
The various samples of raffirtose used in this last experiment had the 
following specific rotatory powers :— 
[a], 
Kahlbaum’s raffinose ............ Peo 
Ditto recrystallised ............ 122°4 
RatnosevlM ie ay..0 ei. DIST te ee 121°6 
aEMMOSO a Veit Lata voatsteds hA2;2 
The low value obtained in the case of the third sample may be attributed 
to imperfect drying rather than to impurity. Probably, the greater activity 
of the invertase in the case of commercial raffinose was conditioned by the 
presence of traces of “ acid ” impurity (cp. X, p. 362). 
The results afford clear proof that invertase is a far less effective hydrolyst 
of the cane-sugar section of raffinose than of cane-sugar itself, being at least 
