o be produced by a spontaneous vital
process, and is believed to be propagated and enlarged in so short a
time by solitary generation as to become visible to the naked eye; I
mean the green matter first attended to by Dr. Priestley, and called
by him conferva fontinalis. The proofs, that this material is a
vegetable, are from its giving up so much oxygen, when exposed to the
sunshine, as it grows in water, and from its green colour.

Dr. Ingenhouz asserts, that by filling a bottle with well-water, and
inverting it immediately into a basin of well-water, this green
vegetable is formed in great quantity; and he believes, that the water
itself, or some substance contained in the water, is converted into
this kind of vegetation, which then quickly propagates itself.

M. Girtanner asserts, that this green vegetable matter is not produced
by water and heat alone, but requires the sun's light for this
purpose, as he observed by many experiments, and thinks it arises from
decomposing water deprived of a part of its oxygen, and laughs at Dr.
Priestley for believing that the seeds of this conferva, and the
parents of microscopic animals, exist universally in the atmosphere,
and penetrate the sides of glass jars; Philos. Magazine for May 1800.

Besides this green vegetable matter of Dr. Priestley, there is another
vegetable, the minute beginnings of the growth of which Mr. Ellis
observed by his microscope near the surface of all putrefying
vegetable or animal matter, which is the mucor or mouldiness; the
vegetation of which was amazingly quick so as to be almost seen, and
soon became so large as to be visible to the naked eye. It is
difficult to conceive how the seeds of this mucor can float so
universally in the atmosphere as to fix itself on all putrid matter in
all places.

_Theory of Spontaneous Vitality._

IV. In animal nutrition the organic matter of the bodies of dead
animals, or vegetables, is taken into the stomach, and there suffers
decompositions and new combinations by a chemical process. Some parts
of it are however absorbed by the lacteals as fast as they are
produced by this process of digestion; in which circumstance this
process differs from common chemical operations.

In vegetable nutrition the organic matter of dead animals, or
vegetables, undergoes chemical decompositions and new combinations on
or beneath the surface of the earth; and parts of it, as they are
produced, are perpetually absorbed by the