176 Heilbron
Samuel Clarke, in 1735. It described and explained demonstrations il-
lustrative of “all the effects that Nature produces.” Nonetheless, its en-
compassing subject—the “speculative knowledge of all natural bodies,”
as John Harris defi ned “physicks” in 1704—remained largely bookish and
qualitative. Experiment had become central to the investigation, but not
yet to the transmission, of natural knowledge. During the last third of the
seventeenth century, the Accademia del Cimento of Florence, the Royal
Society of London, the Académie des sciences of Paris, the Accademia fi -
sicomatematica romana, and the Collegium Experimentale of Altdorf had
made the pinching and probing of nature with instruments a respectable
and even a virtuous way to obtain natural knowledge.^5
The members of these early academies usually performed experiments
together or before one another as eyewitnesses so that the outcomes could
be certifi ed as contributions to knowledge. The most prized experiments,
because the most clear and striking to several spectators at once, involved
the air pump and other sturdy instruments able to create reliable and
striking effects. A narrowing of the scope of natural philosophy resulted:
experimental philosophy, which emphasized mechanical and pneumatic
experiments, became an important and then the leading sector of natural
philosophy.^6
Newton’s discoveries in optics fi t easily into this program, as did dem-
onstrations of the sorts of forces he supposed at work in the universe.
The fi rst textbook of natural philosophy in this narrow sense was W. J.
’sGravesande’s Physica elementa mathematica experimentis confi rmata, sive
introductio ad philosophiam neutonianam (1720–1721). It and updated texts
on similar lines by Pieter van Musschenbroek, ’sGravesande’s successor as
professor of mathematics and astronomy at the University of Leiden, had
a large circulation in several languages. Despite their titles, they contain
very little mathematics. They also omit everything that now falls in the
domains of biology and geology, and almost everything we would call
chemistry and meteorology, all of which fi gure in Rohault’s Physique. The
same process can be followed in texts independent of the market- leading
Dutch Newtonians. The tradition descending from the Collegium Curio-
sorum, which derived from the Accademia del Cimento, continued in
Christian von Wolff’s Allerhand nützliche Versuche, published almost simul-
taneously with ’sGravesande’s Physica. Wolff admitted mechanics, hydro-
statics, pneumatics, meteorology, fi re, light, color, sound and magnetism,
animals as subjects for experiment in vacuo, and sense organs as examples
of optical and mechanical principles—a more generous selection than
’sGravesande’s but still impoverished as an account of natural phenomena
in general.^7