hottest are in trachyte and the "coal measures," namely, the Comstock
mines in trachyte and the South Balgray in the "coal measures." Mr. Dorsey
considered that experience showed that limestone was the coolest
formation.

* * * * *




GALLISIN, AN UNFERMENTABLE SUBSTANCE IN STARCH SUGAR.


C. Schmitt and A. Coblenzl have made a careful investigation of the
unfermentable substances found in commercial starch sugars, and have
succeeded in isolating a definite compound, to which they give the name
gallisin. The method of separation and purification which they made use of
is as follows: 5 kilogrammes of commercial starch sugar were allowed to
ferment. At a temperature of 18-20° C. and with a solution containing 20
per cent. the fermentation was complete in five to six days. It was
filtered; the perfectly clear, almost colorless, liquid evaporated as far
as possible on the water-bath, and the sirup while still warm brought into
a good-sized flask. The sirup was then well shaken with a large excess of
absolute alcohol, when it became viscous, but did not mix with the
alcohol. The latter was poured off, replaced by fresh alcohol, and again
shaken. When this shaking with alcohol has been repeated several times,
the sirup is finally changed to a yellowish-gray mass. This is now brought
into a large mortar, and rubbed up under a mixture of alcohol and ether.
After some time the whole mass is transformed into a gray powder. It is
quickly filtered off with the aid of an aspirator, washed with alcohol and