th the exception
of a few partial corrections we have nothing to efface.

This vast supply of positive or probable facts, either demonstrated or
anticipated, furnishes food, substance and impulse to the intellect
of the eighteenth century. Consider the leaders of public opinion,
the promoters of the new philosophy: they are all, in various degrees,
versed in the physical and natural sciences. Not only are they familiar
with theories and authorities, but again they have a personal knowledge
of facts and things. Voltaire[3108] is among the first to explain
the optical and astronomical theories of Newton, and again to make
calculations, observations and experiments of his own. He writes memoirs
for the Academy of Sciences "On the Measure of Motive Forces," and "On
the Nature and Diffusion of Heat." He handles Reamur's thermometer,
Newton's prism, and Muschenbrock's pyrometer. In his laboratory at Cirey
he has all the known apparatus for physics and chemistry. He experiments
with his own hand on the reflection of light in space, on the increase
of weight in calcified metals, on the renewal of amputated parts of
animals, and in the spirit of a true savant, persistently, with constant
repetitions, even to the beheading of forty snails and slugs, to verify
an assertion made by Spallanzani.--The same curiosity and the same
preparation prevails with all imbued with the same spirit. In the
other camp, among the Cartesians, about to disappear, Fontenelle is an
excellent mathematician, the competent biographer of all eminent men of
science, the official secretary and true representative of the Academy
of Sciences. In other places, in the Academy of Bordeaux, Montesquieu
reads discourses on the mechanism of the echo, and on the use of the
renal glands; he dissects frogs, tests the effect of heat and cold
on animated tissues, and publishes observations on plants and
insects.--Rousseau, the least instructed of all, attends the lectures
of the chemist Rouelle, botanizing and appropriating to himself all the
elements of human knowledge with which to write his "Emile."--Diderot
taught mathematics and devoured every science and art even to the
technical processes of all industries. D'Alembert stands in the first
rank of mathematicians. Buffon translated Newton's theory of flux, and
the Vegetable Statics of Hales; he is in turn a metallurgist, optician,
geographer, geologist and, last of all, an anatomist. Condillac, to
explain the use of