158 
EXTRACTS FROM FOREIGN PERIODICALS. 
thought decisive by the great majority of naturalists interested in either the 
zoological or geological relations of this remarkable fos il. 
MINERALOGY. 
10. Substitute for Emery. —Topaz, the discovery of which in this country was 
first announced in Sillimaris American Journal , many years since, has continued 
to occur in such abundance (although not in general beautiful), that the owner of 
the locality has been induced to crush it to powder as a substitute for emery. 
The hardness of the Topaz is such (8) as to place it next to Corundum (9), with 
the exception of Spinella, Automolite, and Chrvsoberyl, which approach nearer 
to Corundum than Topaz ; but they have never been found in the quantity that 
the latter occurs in Monroe. We understand that those who have made use 
of this substitute find, that for all common purposes it answers very well. 
11. Bog Earth a Substitute for Coal. —Monsieur Orguesson, a Swede b}^ 
birth, and proprietor of immense portions of land in the neighbourhood of Hel¬ 
singfors, in Finland,‘has invented an apparatus by means of which he renders 
bog earth as hard and compact as Coal. In this state it easily takes fire, gives a 
pure and brilliant flame, and produces as much heat, if not more, than Coal. 
METEOROLOGY. 
12. Vegetable Weather-prophet.' —The attention of scientific men is just now 
directed to a curious discovery of Prof. Stiefel —well known throughout Germany 
for his researches in Natural Science—the result of which has been the attain¬ 
ment of a more accurate knowledge of those changes to which the atmosphere is 
subjected, than was possible by the old method. The instruments hitherto in 
use have been the thermometer and the barometer, but an unerring standard 
has been considered a desideratum; that is said to have been at last supplied in 
the shape of Geranium-fruit, the awns of which are in and evolved by the dryness 
or humidity of the atmosphere, in obedience to laws so regular and unvarying, 
that being fixed upon a dial-plate properly graduated, the change from one part 
of a room to another may be noted wuth the greatest accuracy. A paper on the 
subject was to be read at the meeting of German naturalists, held this year at 
Freyburg. Prof. |Stiefel is the greatest weather-doctor in southern Germany, 
and has, for many years, tabulated all changes in the atmosphere, according to a 
plan suggested by Goethe; but he does not venture to predict for more than 
twenty-four hours at a time, and laughs at our weather-prophets. By observa¬ 
tion, he says, one may get the rule , but not the exceptions.—Athenaeum. 
