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MICROSCOPICAL INVESTIGATION. 353
MICROSCOPICAL INVESTIGATION IN ANATOMY
AND EXPERIMENT IN PHYSIOLOGY.
THE 16th century witnessed the splendid triumphs of
anatomists, who investigated the structure of the human
body; physiological experiment, which created a science
founded on facts, impressed its mark upon the 17th century.
Anatomy was an established science already in the 16th
century, in its essential outlines at least, and so far as was
possible by investigation with the unaided eye. The
following periods had the tasks assigned to them of testing
the scientific results already won, of correcting and of completing
them by examination of details, and of extending and
enlarging them. Investigation acquired by the aid of the
magnifying glass and the microscope a depth and a solidity
hitherto unattainable. The anatomists devoted their attention
chiefly to the finer structure of organs, a study more
successfully pursued by means of the newly-discovered
optical instruments.
LEEUWENHOEK possessed the best microscope of his time,
constructed by himself. It magnified 160-270 times, whereas
the instruments used by other investigators magnified at'
most 143 times.' LEEUWENHOEK described the tubular
structure of the bones, and noticed the bone-corpuscles,
which afterwards were rediscovered and more accurately
described by PURKINJE.* He referred also to the enamel
of the teeth, while other particulars of their structure were
explained by MALPIGHI. CLOPTON HAVERS discovered
the canals in bones, which still bear his name ;f DU HAMEL
studied the formation of bony tissue, and recognized that
it is developed by the help of the periosteum out of
cartilage, the vessels bringing the formative material
required according to the pattern laid down in cartilage;
J. T. KLINKOSCH, of Prague, taught the origin of bone
* P. J. HAAXMANN in the Nederl. Tijdschr. v. Geneesk 1871, ii, 1-86.
f CL. HAVERS: Observationes de ossibus, Amstelod. 1731, p. 63.
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