We present herewith, from _L'Illustration_, views of the amphitheater, and
first and second year laboratories of the new Central School at Paris.
[Illustration: THE NEW CENTRAL SCHOOL AT PARIS.]
The amphitheater does not perceptibly differ from those of other schools.
It consists of a semicircle provided with rows of benches, one above
another, upon which the pupils sit while listening to lectures and taking
notes thereof. Several blackboards, actuated by hydraulic motors, serve
for demonstration by the professor, who, if need be, will be enabled,
thanks to the electricity and gas put within his reach, to perform
experiments of various kinds. Electricity is brought to him by wires, just
as water and gas are by pipes. It will always be possible for him to
support the theory that he is explaining by experiments which facilitate
the comprehension of it by the pupils. The amphitheater is likewise
provided with a motor which furnishes the professor with power whenever he
has recourse to a mechanical application.
It will not be possible for the pupils to have their attention distracted
by what is going on outside of the amphitheater, since the architect has
taken the precaution to use ground glass in the windows.
[Illustration: THE NEW CENTRAL SCHOOL AT PARIS.]
As regards the laboratories, it is allowable to say that they constitute
the first great school of experimental chemistry in France. The first year
laboratory consists of a series of tables, provided with evaporating
hoods, at which a series of pupils will study general chemistry
experimentally. Electricity, and gas and water cocks are within reach of
each operator, and all the deleterious emanations from the acids that are
used or are produced in studying a body will escape through the hoods.
The third year laboratory is designed for making commercial analyses.
These latter are made by either dry or wet way. The first method employs
water chiefly as a vehicle, and alkaline solutions as reagents. The second
employs reagents in a dry state, and the action of which requires lamp and
furnace heat. The furnaces employed in the new school are like those
almost exclusively used industrially for the analysis of ores. The tables
upon which analyses by dry way are made are large enough to allow sixteen
pupils to work.
[Illustration: THE NEW CENTRAL SCHOOL AT PARIS.]
Analyses by wet way are made upon tables, with various sorts of vessels.
Along with water, gas, and electricity, the pupils have at their disposal
a faucet from whence they may draw the hydrosulphuric acid which is so
constantly used in laboratory operations.
The architect of the new school is Mr. Denfer.
* * * * *
[NATURE.]
RESEARCHES ON THE ORIGIN AND LIFE-HISTORIES OF THE LEAST AND LOWEST
LIVING THINGS.
By Rev. W.H. DALLINGER, LL. D.
To all who have familiarized themselves, even cursorily, with modern
scientific knowledge, it is well known that the mind encounters the
_infinite_ in the contemplation of minute as well as in the study of vast
natural phenomena. The farthest limit we have reached, with the most
gigantic standard of measurement we could well employ, in gauging the
greatness of the universe, only leaves us with an overwhelming
consciousness of the awful greatness--the abyss of the infinite--that lies
beyond, and which our minds can never measure. The indefinite has a limit
somewhere; but it is not the indefinite, it is the measureless, the
infinite, that vast extension forces upon our minds. In like manner, the
immeasurable in minuteness is an inevitable mental sequence from the facts
and phenomena revealed to us by a study of the _minute_ in nature. The
practical divisibility of matter disclosed by modern physics may well
arrest and astonish us. But biology, the science which investigates the
phenomena of all living things, is in this matter no whit behind. The most
universally diffused organism in nature, the least in size with which we
are definitely acquainted, is so small that fifty millions of them could
lie together in the one-hundredth of an inch square. Yet these definite
living things have the power of locomotion, of ingestion, of assimilation,
of excretion, and of enormous multiplication, and the material of which
the inconceivably minute living speck is made is a highly complex chemical
compound. We dare not attempt a conception of the minuteness of the
ultimate atoms that compose the several simple elements that thus
mysteriously combine to form the complex substance and properties of this
least and lowliest living thing. But if we could even measure these, as a
mental necessity, we are urged indefinitely on to a minuteness without
conceivable limit, in effect, a minuteness that is beyond all finite
measure or conception. So that, as modern physics and optics have enabled
us not to conceive merely, but to actually realize, the vastness of
spatial extension, side by side with subtile tenuity and extreme
divisibility of matter, so the labor, enthusiasm, and perseverance of
thirty years, stimulated by the insight of a rare and master mind, and
aided by lenses of steadily advancing perfection, have enabled the student
of life-forms not simply to become possessed of an inconceivably broader,
deeper, and truer knowledge of the great world of visible life, of which
he himself is a factor, but also to open up and penetrate into a world of
minute living things so ultimately little that we cannot adequately
conceive them, which are, nevertheless, perfect in their adaptations and
wonderful in their histories. These organisms, while they are the least,
are also the lowliest in nature, and are to our present capacity totally
devoid of what is known as organic structure, even when scrutinized with
our most powerful and perfect lenses. Now these organisms lie on the very
verge and margin of the vast area of what we know as living. They possess
the essential properties of life, but in their most initial state. And
their numberless billions, springing every moment into existence wherever
putrescence appeared, led to the question, How do they originate? Do they
spring up _de novo_ from the highest point on the area of _not-life_,
which they touch? Are they, in short, the direct product of some yet
uncorrelated force in nature, changing the dead, the unorganized, the
not-living, into definite forms of life? Now this is a profound question,
and that it is a difficult one there can be no doubt. But that it is a
question for our laboratories is certain. And after careful and prolonged
experiment and research the legitimate question to be asked is, Do we find
that, in our laboratories and in the observed processes of nature now, the
not-living can be, without the intervention of living things, changed into
that which lives?
To that question the vast majority of practical biologists answer without
hesitancy, _No_, we have no facts to justify such a conclusion. Prof.
Huxley shall represent them. He says: "The properties of living matter
distinguish it absolutely from all other kinds of things;" and, he
continues, "the present state of our knowledge furnishes us with no link
between the living and the not-living." Now let us carefully remember that
the great doctrine of Charles Darwin has furnished biology with a
magnificent generalization; one indeed which stands upon so broad a basis
that great masses of detail and many needful interlocking facts are, of
necessity, relegated to the quiet workers of the present and the earnest
laborers of the years to come. But it is a doctrine which cannot be
shaken. The constant and universal action of variation, the struggle for
existence, and the "survival of the fittest," few who are competent to
grasp will have the temerity to doubt. And to many, that lies within it as
a doctrine, and forms the fibre of its fabric, is the existence of a
continuity, an unbroken stream of unity running from the base to the apex
of the entire organic series. The plant and the animal, the lowliest
organized and the most complex, the minutest and the largest, are related
to each other so as to constitute one majestic organic whole. Now to this
splendid continuity practical biology presents no adverse fact. All our
most recent and most accurate knowledge confirms it. But _the_ question
is, Does this continuity terminate now in the living series, and is there
then a break--a sharp, clear discontinuity, and beyond, another realm
immeasurably less endowed, known as the realm of not-life? or Does what
has been taken for the clear-cut boundary of the vital area, when more
deeply searched, reveal the presence of a force at present unknown, which
changes not-living into the living, and thus makes all nature an unbroken
sequence and a continuous whole? That this is a great question, a question
involving large issues, will be seen by all who have familiarized
themselves with the thought and fact of our times. But we must treat it
purely as a question of science; it is not a question of _how_ life
_first_ appeared upon the earth, it is only a question of whether there is
any natural force _now_ at work building not-living matter into living
forms. Nor have we to determine whether or not, in the indefinite past,
the not-vital elements on the earth, at some point of their highest
activity, were endowed with, or became possessed of, the properties of
life.
[Illustration: Fig. 1]
On that subject there is no doubt. The elements that compose
protoplasm--the physical basis of all living things--are the familiar
elements of the world without life. The mystery of life is not in the
elements that compose the vital stuff. We know them all, we know their
properties. The mystery consists _solely_ in _how_ these elements can be
so combined as _to acquire_ the transcendent properties of life. Moreover,
to the investigator it is not a question of _by what means_ matter
dead--without the shimmer of a vital quality--became either slowly or
suddenly possessed of the properties of life. Enough for us to know that
whatever the power that wrought the change, that power was competent, as
the issue proves. But that which calm and patient research has to
determine is whether matter demonstrably _not living_ can be, without the
aid of organisms already living, endowed with the properties of life.
Judged of hastily, and apart from the facts, it may appear to some minds
that an origin of life from not-life, by sheer physical law, would be a
great philosophical gain, an indefinitely strong support of the doctrine
of evolution. If this were so, and, indeed, so far as it is believed to be
so, it would speak and does speak volumes in favor of the spirit of
science pervading our age. For although the vast majority of biologists in
Europe and America accept the doctrine of evolution, they are almost
unanimous in their refusal to accept as in any sense competent the reputed
evidence of "spontaneous generation;" which demonstrates, at least, that
what is sought by our leaders in science is not the mere support of
hypotheses, cherished though they may be, but the truth, the uncolored
truth, from nature. But it must be remembered that the present existence
of what has been called "spontaneous generation," the origin of life _de
novo_ to-day, by physical law, is by no means required by the doctrine of
evolution. Prof. Huxley, for example, says: "If all living beings have
been evolved from pre-existing forms of life, it is enough that a single
particle of protoplasm should _once_ have appeared upon the globe, as the
result of no matter what agency; any further independent formation of
protoplasm would be sheer waste." And why? we may ask. Because one of the
most marvelous and unique properties of protoplasm, and the living forms
built out of it, _is the power_ to multiply indefinitely and for ever!
What need, then, of spontaneous generation? It is certainly true that
evidence has been adduced purporting to support, if not establish, the
origin in dead matter of the least and lowest forms of life. But it
evinces no prejudice to say that it is inefficient. For a moment study the
facts. The organisms which were used to test the point at issue were those
known as _septic_. The vast majority of these are inexpressibly minute.
The smallest of them, indeed, is so small that, as I have said, fifty
millions of them, if laid in order, would only fill the one-hundredth part
of a cubic inch. Many are relatively larger, but all are supremely minute.
Now, these organisms are universally present in enormous numbers, and ever
rapidly increasing in all moist putrefactions over the surface of the
globe.
Take an illustration prepared for the purpose, and taken direct from
nature. A vessel of pure drinking water was taken during the month of July
at a temperature of 65 deg. F., and into it was dropped a few shreds of
fish muscle and brain. It was left uncovered for twelve hours; at the end
of that time a small blunt rod was inserted in the now somewhat opalescent
water, and a minute drop taken out and properly placed on the microscope,
and, with a lens just competent to reveal the minutest objects, examined.
The field of view presented is seen in Fig. 1, A. But--with the exception
of the dense masses which are known as zoogloea or bacteria, fused
together in living glue--the whole field was teeming with action; each
minute organism gyrating in its own path, and darting at every visible
point. The same fluid was now left for sixteen hours, and once more a
minute drop was taken and examined with the same lens as before. The field
presented to the eye is depicted in Fig. 1, B, where it is visible that
while the original organism persists yet a new organism has arisen in and
invaded the fluid. It is a relatively long and beautiful spiral form, and
now the movement in the field is entrancing. The original organism darts
with its vigor and grace, and rebounds in all directions. But the spiral
forms revolving on their axes glide like a flight of swallows over the
ample area of their little sea. Ten hours more elapsed and, without change
of circumstances, another drop was taken from the now palpably putrescent
fluid. The result of examination is given in Fig. 1, C, where it will be
seen that the first organism is still abundant, the spiral organism is
still present and active, but a new and oval form, not a bacterium, but a
_monad_, has appeared. And now the intensity of action and beauty of
movement throughout the field utterly defy description, gyrating, darting,
spinning, wheeling, rebounding, with the swiftness of the grayling and the
beauty of the bird. Finally, at the end of another eight to sixteen hours,
a final "dip" was taken from the fluid, and under the same lens it
presented as a field what is seen in Fig. 1, D, where the largest of the
putrefactive organisms has appeared and has even more intense and more
varied movements than the others. Now the question before us is, "How did
these organisms arise?" The water was pure; they were not discoverable in
the fresh muscle of fish. Yet in a dozen hours the vessel of water is
peopled with hosts of individual forms which no mathematics could number!
How did they arise? From universally diffused eggs, or from the direct
physical change of dead matter into living forms? Twelve years ago the
life-histories of these forms were unknown. We did not know biologically
how they developed. And yet with this great deficiency it was considered
by some that their mode of origin could be determined by heat experiments
on the adult forms. Roughly, the method was this: It was assumed that
nothing vital could resist the boiling point of water. Fluids, then,
containing full-grown organisms in enormous multitudes, chiefly bacteria,
were placed in flasks, and boiled for from five to ten minutes. While they
were boiling the necks of the flasks was hermetically closed; and the
flask was allowed to remain unopened for various periods. The reasoning
was: "Boiling has killed all forms of vitality _in_ the flask; by the
hermetical sealing nothing living can gain subsequent access to the fluid;
therefore, if living organisms do appear when the flask is opened, they
must have arisen in the dead matter _de novo_ by spontaneous generation,
but if they do never so arise, the probability is that they originate in
spores or eggs."
Now it must be observed concerning this method of inquiry that it could
never be final; it is incompetent by deficiency. Its results could never
be exhaustive until the life-histories of the organisms involved were
known. And further, although it is a legitimate method of research for
partial results, and was of necessity employed, yet it requires precise
and accurate manipulation. A thousand possible errors surround it. It can
only yield scientific results in the hands of a master in physical
experiment. And we find that when it has secured the requisite skill, as
in the hands of Prof. Tyndall, for example, the result has been the
irresistible deduction that living things have never been seen to
originate in not-living matter. Then the ground is cleared for the
strictly biological inquiry, How do they originate? To answer that
question we must study the life histories of the minutest forms with the
same continuity and thoroughness with which we study the development of a
crayfish or a butterfly. The difficulty in the way of this is the extreme
minuteness of the organisms. We require powerful and perfect lenses for
the work. Happily during the last fifteen years the improvement in the
structure of the most powerful lenses has been great indeed. Prior to this
time there were English lenses that amplified enormously. But an
enlargement of the image of an object avails nothing, if there be no
concurrent disclosure of detail. Little is gained by expanding the image
of an object from the ten-thousandth of an inch to an inch, if there be
not an equivalent revelation of hidden details. It is in this revealing
quality, which I shall call _magnification_ as distinct from
_amplification_, that our recent lenses so brilliantly excel. It is not
easy to convey to those unfamiliar with objects of extreme minuteness a
correct idea of what this power is. But at the risk of extreme simplicity,
and to make the higher reaches of my subject intelligible to all, I would
fain make this plain.
But to do so I must begin with familiar objects, objects used solely to
convey good relative ideas of minute dimension. I begin with small objects
with the actual size of which you are familiar. All of us have taken a
naked eye view of the sting of the wasp or honey bee; we have a due
conception of its size. This is the scabbard or sheath which the naked eye
sees.[3] Within this are two blades terminating in barbed points. The
point of the scabbard more highly magnified is presented, showing the
inclosed barbs. One of the barbs, looked at on the barbed edge, is also
seen. Now these two barbed stings are tubes with an opening in the end of
the barb. Each is connected with the tube of the sac, C. This Is a
reservoir of poison, and D is the gland by which it is secreted. Now I
present this to you, not for its own sake, but simply for the comparison,
a comparison which struck the earliest microscopists. Here is the scabbard
carefully rendered. One of the stings is protruded below its point, as in
the act of stinging; the other is free to show its form. Now the actual
length of this scabbard in nature was the _one-thirtieth_ of an inch. I
have taken the point, C, of a fine cambric sewing needle, and broken it
off to slightly less than the one-thirtieth of an inch, and magnified it
as the sting is magnified. Now here we obtain an instance of what I mean
by magnification. The needle point is not merely bigger, unsuspected
details start into view. The sting is not simply enlarged, but all its
structure is revealed. Nor can we fail to note that the _finish_ of art
differs from that of nature. The homogeneous gloss of the needle
disappears under the fierce scrutiny of the lens, and its delicate point
becomes furrowed and riven. But Nature's finish reveals no flaw, it
remains perfect to the last.
[Footnote 3: A magnified image of the bee's sting was projected on the
screen.]
We may readily amplify this. The butterflies and moths of our native lands
we all know; most of us have seen their minute eggs. Many are quite
visible to the unaided eye; others are extremely minute. A gives the egg
of the small white butterfly;[4] B, that of the small tortoiseshell; C,
that of the waved umber moth; D, that of the thorn moth; E, that of the
shark moth; at F we have the delicate egg of the small emerald butterfly,
and at G an American skipper; and finally, at H, the egg of a moth known
as mania maura. In all this you see a delicacy of symmetry, structure, and
carving, not accessible to the eye, but clearly unfolded. We may, from our
general knowledge, form a correct notion of the average relation in size
existing between butterflies and their eggs; so that we can compare. Now
there is a group of extremely minute, insect-like forms that are the
parasites of birds. Many of them are just plainly visible to the naked
eye, others are too minute to be clearly seen, and others yet again wholly
elude the unaided sight. The epizoa generally lodge themselves in various
parts of the plumage of birds; and almost every group of birds becomes the
host of some specific or varietal form with distinct adaptations. There is
here seen a parasite that secretes itself in the inner feathers of the
peacock, this is a form that attacks the jay, and here is one that
secretes itself beneath the plumage of the partridge.
[Footnote 4: A series of the eggs of butterflies were then shown, as were
the objects successively referred to, but not here reproduced.]
Now these minute creatures also deposit eggs. They are placed with
wonderful instinct in the part of the plumage and the part of the feather
which will most conserve their safety; and they are either glued or fixed
by their shape or by their spine in the position in which they shall be
hatched. I show here a group of the eggs of these minute creatures. I need
not call your attention to their beauty; it is palpable. But I am fain to
show you that, subtle and refined as that beauty is, it is clearly brought
out. The flower-like beauty of the egg of the peacock's parasite, the
delicate symmetry and subtle carving of the others, simply entrance an
observer. Note then that it is not merely _enlarged_ specks of form that
we are beholding, but such true magnifications of the objects as bring out
all their subtlest details. And it is _this_ quality that must
characterize our most powerful lenses. I am almost compelled to note in
passing that the _beauty_ of these delicate and minute objects must not be
considered _an end_--a purpose--in nature. It is not so. The form is what
it is because it _must be_ so to serve the end for which the egg is
formed. There is not a superfluous spine, not a useless petal in the
floral egg, not an unneeded line of chasing in the decorated shell. It is
shaped beautifully because its shape is needed. In short, it is Nature's
method; the identification of beauty and use. But to resume. We may at
this point continue our illustrations of the analytical power of moderate
lenses by a beautiful instance. We are indebted to Albert Michael, of the
Linnean Society of England, for a masterly treatise on a group of acari,
or _mites_, known as the _oribatidæ_. Many of these he has discovered. The
one before you is a full grown nymph of what is known as a _palmicinctum_.
It is deeply interesting as a form; but for us its interest is that it is
minute, being only a millimeter in length. But it repeatedly casts the
dorsal skin of the abdomen. Each skin is bordered by a row of exquisite
scales; and then successive rows of these scales persist, forming a
protection to the entire organism. Mark then that we not only reveal the
general form of the nymph, but the lens reveals the true structure of the
scales, not enlargement merely, but detail. The egg of the organism, still
more magnified, is also seen.
To vary our examples and still progress. We all know the appearance and
structure of chalk. The minute foraminifera have, by their accumulated
tests, mainly built up its enormous masses. But there is another chalk
known as Barbados earth; it is silicious, and is ultimately composed of
minute and beautiful skeletons such as those which, enormously magnified,
you now see. These were the glassy envelopes which protected the living
speck that dwelt within and built it. They are the minutest of the
Radiolaria, which peopled in inconceivable multitudes the tertiary oceans;
and, as they died, their minute skeletons fell down in a continuous rain
upon the ocean bed, and became cemented into solid rock which geologic
action has brought to the surface in Barbados and many other parts of the
earth. If a piece of this earth, the size of a bean, be boiled in dilute
acid and washed, it will fall into powder, the ultimate grains of which
are such forms as these which you see. The one before you is an instance
of exquisite refinement of detail. The form from which the drawing of the
magnified image was made was extremely small--a mere white speck in the
strongest light upon a black ground. But you observe it is not a speck of
form merely enlarged. It is not merely beauty of outline made bigger. But
there is--as in the delicate group you now see--a perfect opening up of
otherwise absolutely invisible details. We may strengthen this evidence in
favor of the analytical power of our higher lenses by one more _familiar_
example, and then advance to the most striking illustration of this power
which our most perfect and powerful lenses can afford. I fear that may be
taking too much for granted to assume that every one in an audience like
this has seen a human flea! Most, however, will have a dim recollection or
suggestive instinct as to its size in nature. Nothing striking is revealed
by this amount of magnification excepting the existence of breathing pores
or spiracles along the scale armor of its body. But there is a trace of
structure in the terminal ring of the exo-skeleton which we cannot clearly
define, and of which we may desire to know more. This can be done only by
the use of far higher powers.
To effect this, we must carefully cut off this delicate structure, and so
prepare it that we may employ upon it the first of a series of our highest
powers. The result of that examination is given here.[5] You see that the
whole organ has a distinct form and border, and that its carefully carved
surface gives origin to wheel-like areolæ which form the bases of delicate
hairs. The function of this organ is really unknown. It is known from its
position as the _pygidium_; and from the extreme sensitiveness of the
hairs to the slightest aerial movement, may be a tactile organ warning of
the approach of enemies; the eyes have no power to see. But we have not
reached the ultimate accessible structure of this organ. If we place a
portion of the surface under one of the finest of our most powerful
lenses, this will be the result.[6] Now, without discussing the real
optical or anatomical value of this result as it stands, what I desire to
remind you of is: