8 Conservative.
consider what happens when water
rusts iron. In a certain sense the iron
may bo said to eat the oxygen , reject
the hydrogen , and grow , or increase
in weight by what it feeds on ; but
the result is not a bigger piece of
iron , but a new substance , rust , or
oxide of iron. That living matter
should feed internally is not so won
derful , for its semi-fluid condition may
well enable foreign molecules to pene
trate its mass and conie in contact
with its own interior molecules ; but it
is an experience different from any
thing known in the inorganic world
that it should bo able to manufacture
molecules of protoplasm like its own
out of these foreign molecules , and
thus grow by assimilation. For in
stance , when amobae , bacteria , and
other low organisms live and multiply
iu chemical solutions which contain
no protoplasm , but only inorganic
compounds containing the requisite
atoms for making protoplasm , or when
a plant not only chemically decom
poses carbonic dioxide , exhaling the
oxygen and depositing the carbon in
its stem and leaves , but also from this
and other elements drawn from the
soil or air , manufactures the living
protoplasm which courses through its
channels , the result is that life has
added to itself by utilizing non-living
materials. If wo take sensation , this ,
in its last analysis , is change , or mole
cular motion , induced in a body by
the action of its environment. Here
there is a certain analogy between
living and non-living matter , for the
latter does respond to changes in the
surrounding environment , as in the
case of heat and electricity ; but liv
ing matter is far more sensitive , the
changes are far more frequent and in
volved , and iu certain cases they
Yl are accompanied by a sensation of
fc' < what should be called not conscious
ness , but conaentience , which in the
higher organism rises into a percep
tion of voluntary effort or free-will
as a factor in the transformation of
energies. Thus it happens that in the
case of dead matter the alterations
produced by a change of conditions ,
follow fixed laws and can be predicted
and calculated , while those of living
matter are more complicated I can
not say more capricious , for my con
viction is that the inadequacy of our
knowledge explains a great deal. We
can tell , however , how much an iron
bar will expand with heat , but we
cannot say whether , if a Jparticle of
food is brought within reach of an
amoeba , it will or will not shoot out
a finger to seize it. If the amoeba is
hungry , it probably will ; if it is en
joying a rest after a meal , it probably
will not.
Sensation.
The cane of sensation includes that
of motion , which is after all only sen
sation applied in the liberation of
energy , which has by some chemical
process been stored up , either in the
living mass , or in some special organ
of it , such as a muscle. Iron , for ex
ample , moves when it expands by heater
or is attracted by a magnet ; but it
moves , like the planets , by fixed and
calculable laws ; while living matter
moves , as might be expected from the
variable character of its sensation , in
a manner which , with our present
knowledge , cannot , as a general rule ,
bo calculated. There are cases , how
ever , of reflex or involuntary motion ,
where , oven in the highest living or
ganisms sensation and motion seem to
follow change of environment , in a
fixed and invariable sequence , as iu
shrinking from pain , touching , or gal
vanizing a nerve ; and it is possible
that the apparent spontaneity and var
iability of living motion is only the
result of the almost infinitely greater
complexity and mobility of the ele
ments of living matter.
Reproduction.
Reproduction remains for considera
tion. It is the faculty most character
istic of life , as well as the one which
distinguishes most sharply the organic
from the inorganic world. In the in
organic world there is no known pro
cess by which dead matter reproduces
itself , as the cell does when it con
tracts iu the middle and splits up into
two cells , which in their turn propa
gate an endless number of similar
cells , increasing in geometrical pro
gression until they supply the raw
material from which all the countless
varieties of living organisms are built
up , which , in their turn , repeat the
process , and reproduce themselves in
offspring. This is the real mystery of
life ; we can , to some extent , under
stand how its other faculties might
arise from an extension of the known
qualities and laws of matter and of
energy ; but wo can discern no analogy
between the non-reproductive nitrog
enous carbon compound , which
makes so near an approach to proto
plasm in its chemical composition , and
the reproductive protoplasm , which
is fertile , increases and multiplies ,
and replenishes the earth. Can the
gap be bridged over : can protoplasm
be manufactured out of chemical el
ements ? It is done every day by
plants which make protoplasm out of
inorganic elements , and by the lowest
forms of vegetablelif e which live and
multiply in chemical solutions. It is
done also in the life history of all in
dividuals whose primitive cell or
ovum makes thousands or millions of
other cells , each containing within its
enclosing membrane as much proto
plasm as there was in the unit from
which they started. But in all these
instances there was the living prin
ciple to start with , existing in the
primitive speck of protoplasm , from
which everything else was developed.
Can this primitive speck bo created ;
or iu other words , can protoplasm bo
artificially manufactured by chemical
processes ? The answer must bo No ;
not by any process now known. The
similarity of chemical composition ,
and the increasing conviction of the
universality of natural law and of evolution
lution , have led to a belief that such
spontaneous generation of life might
bo possible , and any number of unsuc
cessful experiments have been made
to produce it. For a time the balance
seemed to be very evenly held be
tween the supporters and opponents of
spontaneous generation. The inves
tigations of the late John Tyndall ,
however , conclusively proved that
while certain bacteria which float in
the air , can , when dry , withstand a
great degree of heat far beyond boil
ing point then the air is absolutely
pure , no life ever appears , and the in
fusions never putrefy. Oil questions
of this character , all who are not ex
pert investigators must be guided by
authority , and we must accept the
dictum of Huxley that biogenesis , or
all life from previous life , is the con
dition at the present day. But in so
doing we must not forget Huxley's
caution , "that with organic chemis
try , molecular physics , and physiology
yet in their infancy , and every day
making prodigious strides , it would
be the height of presumption for any
man to say that the conditions under
which matter assumes the qualities
called vital , may not some day bo ar
tificially brought together. ' ' And
further , "that as a matter not of
proof , but of probability , if it were
given mo to look beyond the abyss of
geologically recorded time , to the
still more remote period when the
earth was passing through chemical
and physical conditions which it can
never see again , I should expect to be
a witness of the evolution of living
protoplasm from non-living matter. ' '
In the meantime what may be said
as to Huxley's reservations is this :
A considerable step has been made in
the direction indicated , by the success
of modern chemistry in forming , arti
ficially , what are called organic com
pounds , that is , substances which were
previously known as products of aui -
mal or vegetable secretions. I may
mention two indigotine , the prin
ciple of the blue coloring matter of the
indigo plant ; and alizarine , that of
madder. These are now articles of com
merce. If chemists can make the in
digotine , which the growing plant
elaborates at the same time as it
elaborates protoplasm , may we not
hope some day to make the latter as
well as the former product ? New
organic compounds of this class are
being formed artificially every day ,