entific world hastened to adopt it. In this connection
Lavoisier says: "We have, therefore, laid aside the expression metallic
calx altogether, and have substituted in its place the word oxide. By
this it may be seen that the language we have adopted is both copious
and expressive. The first or lowest degree of oxygenation in bodies
converts them into oxides; a second degree of additional oxygenation
constitutes the class of acids of which the specific names drawn from
their particular bases terminate in ous, as in the nitrous and the
sulphurous acids. The third degree of oxygenation changes these into the
species of acids distinguished by the termination in ic, as the nitric
and sulphuric acids; and, lastly, we can express a fourth or higher
degree of oxygenation by adding the word oxygenated to the name of the
acid, as has already been done with oxygenated muriatic acid."(9)

This new work when given to the world was not merely an epoch-making
book; it was revolutionary. It not only discarded phlogiston altogether,
but set forth that metals are simple elements, not compounds of "earth"
and "phlogiston." It upheld Cavendish's demonstration that water itself,
like air, is a compound of oxygen with another element. In short, it was
scientific chemistry, in the modern acceptance of the term.

Lavoisier's observations on combustion are at once important and
interesting: "Combustion," he says, "... is the decomposition of oxygen
produced by a combustible body. The oxygen which forms the base of this
gas is absorbed by and enters into combination with the burning body,
while the caloric and light are set free. Every combustion necessarily
supposes oxygenation; whereas, on the contrary, every oxygenation
does not necessarily imply concomitant combustion; because combustion
properly so called cannot take place without disengagement of caloric
and light. Before combustion can take place, it is necessary that the
base of oxygen gas should have greater affinity to the combustible body
than it has to caloric; and this elective attraction, to use Bergman's
expression, can only take place at a certain degree of temperature which
is different for each combustible substance; hence the necessity of
giving the first motion or beginning to every combustion by the approach
of a heated body. This necessity of heating any body we mean to burn
depends upon certain considerations which have not hitherto been
attended to by any natural philoso