33 ^ 
Infusorial Earth and its Uses. [July, 
which will prove that whatever party is in power we have 
still “ a Government very hostile to Science and to her 
disciples.”* We may well exclaim, to Whig and Tory alike 
— “ A plague on both your houses !” 
IV. INFUSORIAL EARTH AND ITS USES. 
By Dr. W. H. Wahl. 
EOLOGISTS have long since established, beyond 
FWT peradventure, the faCt that there are rocks in the 
interior of continents, at various depths in the earth, 
and at great heights above the sea, which are almost entirely 
made up of the remains of what were once living organisms. 
Such rock-masses, says Lyell, may be compared with modern 
oyster-beds and coral-reefs, and, like them, their rate of 
increase must have been extremely gradual. But there are 
a variety of mineral deposits that are now proved to have 
been derived from plants and animals, of which the organic 
origin was not suspected even by naturalists. Great surprise 
was therefore manifested when Prof. Ehrenberg, of Berlin, 
announced the discovery that a certain kind of siliceous 
stone, called tripoli, was entirely composed of the remains 
of countless millions of extremely minute organic beings. 
This observation of the famous German microscopist speedily 
led to the discovery of the fa 61 that deposits of this character 
were quite abundant, and that they were even being formed 
at the present time over extended areas. The minute 
organisms, whose skeletons make up the bulk of the deposits 
which are now known under the name of infusorial earth, 
have been shown to inhabit the ocean in inconceivable num- 
bers, giving rise to the luminosity of the waters, which has 
been the subject of much discussion, and flourishing in 
almost every place where water stands for several months 
of the year. Their indestructible shells are therefore to be 
found in greater or less quantity in the sedimentary deposits 
of all our bogs, ponds, and slow streams. They are found 
in great abundance beneath peat-bogs, where they consti- 
tute strata, often many feet in thickness and of great extent, 
almost entirely composed of the siliceous carapaces of 
organic beings, so inconceivably minute that millions of 
* Eine der Wissenschaft und ihren Jungern sehr abhold gesinnte Regierung. 
