0"T' LAERT> "! - USP

342
RECENT TIMES.
made important progress. Crystallography was advanced
by the observations of NICHOLAS STENO and GULIELMINI
upon the markings and construction of crystals and the
immutability of their angles. ROBERT BOYLE noticed the ,
crystallization of bismuth out of the molten flux of the I
furnace, and the Danish doctor ERASMUS BARTHOLINUS,j
discovered double refraction in Icelandic calcspar (1670), a
subject more closely investigated by HUYGENS and which
had an important bearing upon the undulatory theory of
light*
At the same time botany was experiencing important
changes. While the knowledge of the different species of 1
plants was increased by numerous works upon the floras
of particular regions and countries, the various attempts to ,J
classify plants according to the similarity of their organs
into families and groups contributed to the more accurate
study of their structure. But the foundation of phytotomy
by MALPIGHI and GREW, their excellent investigations
into the minuter structure of plants, and especially their
labours upon the blossoms, fruits, and seeds of plants,
together with the experimental demonstration of sexuality ^
in the vegetable kingdom by R. J. CAMERARIUS, first*j
rendered it possible to formulate a system corresponding to ?
the demands of science. LiNN^US, who accomplished this*
task, gave a definite and complete form to botany by the
methodical arrangement and characterization of his genera
and species combined with his persistent use of the binary
nomenclature: the discovery of a natural system being
reserved to satisfy the just requirements of future times-f
With the application of the magnifying-glass and micro­
scope to scientific investigations, a new world of life
was opened to zoology of the existence of which none
had hitherto entertained a presentiment. LEEUWENHOEK
discovered infusoria, described certain rotifera, observed
* F. v. KOBELL: Geschichte der Mineralogie, Miinchen 1864, S. 8 et seq. J
f J. SACHS : Geschichte der Botanik. Miinchen 1875, S. 84 et seq., 246 etseq.,
41 7 et seq.