324 Chronicles of Science.  [-Ape, 
The silver medal has recently been awarded to Dr. Leriche for his 
memoir on the Employment of Tannin as a substitute for Cinchona. 
He arrives at the conclusion that pure tannic acid is an excellent 
antiperiodic, and possesses real efficacy in the treatment of all 
intermittent fevers of a simple quotidian type. Now that we are 
threatened by some alarmists with a Quinine famine, the discovery of 
anything which can be used to supplement, or replace, this invaluable 
drug is of the very highest importance. 
IV. GEOLOGY AND PALHONTOLOGY. 
TE past quarter has not been unmarked by some important attempts 
at progress, and amongst these Professor Frankland’s effort to evolve a 
Meteorological theory for the causation of the Glacial era will, whether 
accepted by geologists or not, rank as one of the best towards a 
solution of this recent and remarkable geological period. But as in 
mathematical demonstrations everything depends on the basis taken, 
so in that excellent chemist’s hypothesis the correctness of his con- 
clusions is dependent upon the establishment of the assumptions upon 
which his hypothesis is built—namely, on the actual existence of an 
internal molten core within our earth, and the gradual cooling down of 
our planet from an original incandescent state. The argument Dr. 
Frankland holds is, that the formation of glaciers is a true process of 
distillation, requiring heat as much as cold for its due performance. 
The produce of a still would be diminished, not increased, by an abso- 
lute reduction of temperature, and it is a wider differentiation of tem- 
perature that is required to stimulate its operation into fuller activity. 
The great natural Glacial apparatus is divisible into three parts—the 
evaporator, the condenser, and the receiver. The ocean supplies the 
vapour, the mountains are the ice-bearers or receivers, but the dry air 
of the upper region of the atmosphere, which permits the free radiation 
into space of the heat from aqueous vapour, is the true condenser. The 
sole cause of the phenomena of the Glacial period, then, Professor 
Frankland believes, was a higher temperature of the ocean than obtains 
at present, and the greater differentiation brought about by the differ- 
ence of the rates of cooling of the water of the sea and of the rock- 
masses of the terrestrial crust. According to his notions, all the waters 
of the ocean primarily existed in the atmosphere as vapour, and with 
the gradual cooling of the earth they were first allowed to be deposited 
upon it in a thermal liquid state, and subsequently these ocean-waters 
have been gradually reduced to their present temperature—the glacial 
phenomena occurring during the later stages of this cooling operation. 
Those effects were brought about chiefly by two causes—the high 
specific heat of water compared with granite and other rocks, and the 
comparative facility with which radiant heat escapes from such rocks 
through moist air. The amounts of heat associated with equal weights 
of water and granite are as 5 to 1, or, if equal volumes be taken, water 
