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caution as may properly arise out of our comparative ignorance of
the things for which it stands； it may be truly said； that all
protoplasm is proteinaceous； or； as the white； or albumen； of an
egg is one of the commonest examples of a nearly pure proteine
matter； we may say that all living matter is more or less
albuminoid。
Perhaps it would not yet be safe to say that all forms of
protoplasm are affected by the direct action of electric shocks；
and yet the number of cases in which the contraction of protoplasm
is shown to be affected by this agency increases every day。
Nor can it be affirmed with perfect confidence； that all forms of
protoplasm are liable to undergo that peculiar coagulation at a
temperature of 40…50 degrees centigrade； which has been called
〃heat…stiffening；〃 though Kuhne's ＇101＇ beautiful researches have
proved this occurrence to take place in so many and such diverse
living beings； that it is hardly rash to expect that the law holds
good for all。
Enough has； perhaps； been said to prove the existence of a general
uniformity in the character of the protoplasm； or physical basis；
of life； in whatever group of living beings it may be studied。 But
it will be understood that this general uniformity by no means
excludes any amount of special modifications of the fundamental
substance。 The mineral； carbonate of lime； assumes an immense
diversity of characters； though no one doubts that； under all these
Protean changes； it is one and the same thing。
And now； what is the ultimate fate； and what the origin； of the
matter of life？
Is it； as some of the older naturalists supposed； diffused
throughout the universe in molecules； which are indestructible and
unchangeable in themselves； but； in endless transmigration； unite
in innumerable permutations； into the diversified forms of life we
know？ Or； is the matter of life composed of ordinary matter；
differing from it only in the manner in which its atoms are
aggregated？ Is it built up of ordinary matter； and again resolved
into ordinary matter when its work is done？
Modern science does not hesitate a moment between these
alternatives。 Physiology writes over the portals of life
〃Debemur morti nos nostraque；〃＇102＇
with a profounder meaning than the Roman poet attached to that
melancholy line。 Under whatever disguise it takes refuge； whether
fungus or oak； worm or man； the living protoplasm not only
ultimately dies and is resolved into its mineral and lifeless
constituents； but is always dying； and； strange as the paradox may
sound； could not live unless it died。
In the wonderful story of the Peau de Chagrin；＇103＇ the hero becomes
possessed of a magical wild ass' skin； which yields him the means
of gratifying all his wishes。 But its surface represents the
duration of the proprietor's life； and for every satisfied desire
the skin shrinks in proportion to the intensity of fruition； until
at length life and the last handbreadth of the peau de chagrin；
disappear with the gratification of a last wish。
Balzac's ＇104＇ studies had led him over a wide range of thought and
speculation； and his shadowing forth of physiological truth in this
strange story may have been intentional。 At any rate； the matter
of life is a veritable peau de chagrin； and for every vital act it
is somewhat the smaller。 All work implies waste； and the work of
life results； directly or indirectly； in the waste of protoplasm。
Every word uttered by a speaker costs him some physical loss； and；
in the strictest sense； he burns that others may have lightso
much eloquence； so much of his body resolved into carbonic acid；
water； and urea。 It is clear that this process of expenditure
cannot go on for ever。 But； happily； the protoplasmic peau de
chagrin differs from Balzac's in its capacity of being repaired；
and brought back to its full size； after every exertion。
For example； this present lecture； whatever its intellectual worth
to you； has a certain physical value to me； which is； conceivably；
expressible by the number of grains of protoplasm and other bodily
substance wasted in maintaining my vital processes during its
delivery。 My peau de chagrin will be distinctly smaller at the end
of the discourse than it was at the beginning。 By and by； I shall
probably have recourse to the substance commonly called mutton； for
the purpose of stretching it back to its original size。 Now this
mutton was once the living protoplasm； more or less modified； of
another animala sheep。 As I shall eat it； it is the same matter
altered； not only by death； but by exposure to sundry artificial
operations in the process of cooking。
But these changes； whatever be their extent； have not rendered it
incompetent to resume its old functions as matter of life。 A
singular inward laboratory； which I possess； will dissolve a
certain portion of the modified protoplasm； the solution so formed
will pass into my veins； and the subtle influences to which it will
then be subjected will convert the dead protoplasm into living
protoplasm； and transubstantiate sheep into man。
Nor is this all。 If digestion were a thing to be trifled with； I
might sup upon lobster； and the matter of life of the crustacean
would undergo the same wonderful metamorphosis into humanity。 And
were I to return to my own place by sea； and undergo shipwreck； the
crustacean might； and probably would； return the compliment； and
demonstrate our common nature by turning my protoplasm into living
lobster。 Or； if nothing better were to be had； I might supply my
wants with mere bread； and I should find the protoplasm of the
wheat…plant to be convertible into man； with no more trouble than
that of the sheep； and with far less； I fancy； than that of the
lobster。
Hence it appears to be a matter of no great moment what animal； or
what plant； I lay under contribution for protoplasm； and the fact
speaks volumes for the general identity of that substance in all
living beings。 I share this catholicity of assimilation with other
animals； all of which； so far as we know； could thrive equally well
on the protoplasm of any of their fellows； or of any plant； but
here the assimilative powers of the animal world cease。 A solution
of smelling…salts in water； with an infinitesimal proportion of
some other saline matters； contains all the elementary bodies which
enter into the composition of protoplasm； but； as I need hardly
say； a hogshead of that fluid would not keep a hungry man from
starving； nor would it save any animal whatever from a like fate。
An animal cannot make protoplasm； but must take it ready…made from
some other animal； or some plantthe animal's highest feat of
constructive chemistry being to convert dead protoplasm into that
living matter of life which is appropriate to itself。
Therefore； in seeking for the origin of protoplasm； we must
eventually turn to the vegetable world。 A flui