PROTYLE: WHAT IS IT?
The notion of a primordial form of matter meets us at every stage
of cosmogonical speculation. It is the outcome of an instinctive
persuasion that, if we could only 'lift the painted veil' of phenomena,
the real business of the universe would be found to be proceeding in
the background, 'without haste or rest,' on a settled plan everywhere
the same; that uniformity is fundamental, diversity only incidental;
and that the transformations of the one simplified substance might be
represented by a single formula, the discovery of which would place
in our hands the master-key to the locked secrets of the universe.
Among untutored thinkers some familiar kind of matter, idealized and
generalized, commonly stood for the typical world-stuff. Water was the
first favourite. Thales, the 'wise man' of Miletus, procured his cosmos
by precipitation from an aqueous solution, and many savage tribes
have devised analogous expedients. Anaximenes regarded air as the
universal solvent; Heracleitus replaced it with fire, and set on foot
a scheme of what is now often designated 'elemental evolution.' From
the perpetual 'flux of things' he conceived that the four substances
selected by Empedocles as the bases of nature were not exempt, and a
fragment of his scheme survived in Francis Bacon's admission of the
mutual convertibility of air and water. In the main, however, the
author of the 'Novum Organum' adhered to the Paracelsian doctrine of
an elemental triad,[52] although he regarded the association of salt
as a fundamental 'principle' with sulphur and mercury as inept and
unnecessary.[53]
These twilight fancies faded in the growing light of chemical science;
yet the mental need that they had temporarily appeased survived,
and had somehow to be satisfied. An 'Ur-Stoff' was still in demand,
but the nineteenth century characteristically attempted to supply it
by weight and measure. Dalton's combining equivalents afforded the
warrant for Prout's hydrogen hypothesis. The problem to be faced was
to find a unit-atom by the varied combinations of which all the rest
of the chemical atoms might be formed. The condition indispensable to
be fulfilled was that their weights should be exact multiples of that
of the unit, and it came near to fulfilment by the hydrogen-atom or
semi-atom. It was, nevertheless, a case in which approximate agreement
was of no avail; the adverse decision of the balance finally became
unmistakable; and Prout discreetly fell back, in 1831,[54] upon the
expedient of deriving hydrogen itself from some body lower in the
scale. His hypothesis, in short, dissolved into a conjecture. It had
only emphasized the stipulation that the 'protyle' of the ancients must
be such as would serve not only for the physical unification of the sum
of things, but likewise as the substratum of all the chemical species.
Meanwhile, the theoretical search for it had been carried on in
widely different fields of inquiry. Laplace's speculations, no less
than Herschel's observations, had led to the conception of some
kind of 'fire-mist' as the genuine star-plasm. But its nature and
properties remained indefinite, or were assigned at the arbitrary
choice of adventurous cosmogonists. So the 'shining fluid' of space was
'everything by turns and nothing long,' until Sir William Huggins, in
1864, gave it spectroscopic individuality. The 'recognition-mark' of
nebulium is a vivid green ray, by the emission of which it is known to
have a concrete existence. Yet the little that has besides been learned
about it discountenances its identification with the _materia informis_
of antique philosophy. This we should expect to be the subtlest of all
substances. Professor Campbell, however, has gathered indications that
nebulium is denser than hydrogen. Its luminosity, at least, which is
invariably associated with that of hydrogen, spreads less widely in the
same formations; it is confined to a lower level. The nebulium-atom is
not, then, the chemical or the cosmical unit.
This evasive entity, or something that curiously simulates it, has
proved to be of less recondite origin. Sir William Crookes is amply
justified in claiming the venerable designation of protyle for the
'radiant matter' first produced in his vacuum-tubes nearly thirty years
ago. The discovery was astonishing and unsought, and its significance
has not yet been measured. Matter assumes the 'fourth state,' in which
it is neither solid, liquid, nor gaseous,[55] under the compulsion
of an electric discharge in high vacua. At an exhaustion of about
one-millionth of an atmosphere the manner of its transit abruptly
alters. Conduction gives way to convection. Luminous effects are
abolished. The tubes cease to glow with brilliant, parti-coloured
striæ; the poles are no longer marked by shimmering halos or
brushes; only a green phosphorescence is seen where the glass walls
of the receptacle are struck by the stream of projected particles.
They come, with half the velocity of light, exclusively from the
negative pole, the positive pole remaining inert. Hence the name
'cathode-rays,' bestowed by Goldstein on the carriers of electricity in
highly-exhausted bulbs.
These mysterious, sub-sensible agents possess certain very definite
properties. Their paths are deflected in a magnetic field; they can
traverse metallic films; and their investigation in the open, thereby
rendered feasible, has shown them to possess photographic efficacy,
and the faculty of breaking down electrical insulation; moreover, they
transport a negative charge of fixed amount, and have a determinate
momentum. They are, then, assuredly no mere pulsations of the ether;
unless our senses 'both fail and deceive us,' their quality is
material. Material, yet not quite with the ordinary connotation of the
term. The most essential circumstance about the cathode-rays is that
they remain unmodified by the chemical diversities of the originating
gases.[56] A hydrogen tube yields identically the same radiant matter
as an oxygen or a nitrogen tube. Here, then, at last we have within
our grasp undifferentiated substance--matter not yet specialized,
neither molecular nor atomic, matter destitute of affinities, exempt
from the laws of combination--matter in its inchoate, and perhaps
ultimate form; in a word, the far-sought protyle.
Already, in 1879, Sir William Crookes conjectured the infinitesimal
missiles propelled from the cathode to be the 'foundation-stones
of which atoms are composed.'[57] And in 1886 he pronounced them
more decisively to be the raw material of atoms, which, to Sir John
Herschel's apprehension, bore the unmistakable stamp of a 'manufactured
article.' Nor did his recent commentator refrain from attempting
distantly to divine the method of their construction, or from laying
his finger on the by-products and residues associated with it,[58]
although he felt compelled to relegate the cosmic factory to the edge
of the world, where inconceivable things may happen. All this, indeed,
seemed, in the late Victorian era, like mounting the horse of Astolfo
for a trip to the moon; and sane common-sense pronounced it fantastic
enough to 'make Democritus weep and Heracleitus laugh.'[59] But we have
since learned from Nature herself some tolerance of audacities.
Step by step the new order of ideas has irresistibly come to the front.
It owed its origin to Sir William Crookes's skill in producing high
vacua, and the consequent development in his tubes of radiant effects.
Then, in 1879, universal importance was claimed for them, and matter
in the 'fourth state,' by a revival of the dreams of the ancients,
expanded into a kind of visionary protyle. Philipp Lenard made the next
advance towards its actualization by slipping it, in 1894, through an
aluminium window, and watching its behaviour towards ordinary matter.
Two years later Röntgen rays made their entry on the scene; and before
the end of 1896 Becquerel, hurrying along the track of novelties, came
upon the momentous discovery of radio-activity.
A revision of ideas has ensued. Some time-honoured assumptions have had
to be discarded; so-called laws have been found to need qualification;
the old system of physics is consequently out of gear, and much time
and patient labour must be expended upon the adjustment of the new and
improved system destined to replace it. The leading and indisputable
fact of the actual situation is that a number of hitherto unsuspected
modes of energy have been disclosed as widely operative in nature.
All are of a 'radiant' character. They travel in straight lines with
enormous speed; they start from a material base, and produce their
several effects on reaching a material goal. Now, these effects are
closely alike, notwithstanding that the rays themselves are radically
dissimilar. Those of the cathodic kind are corpuscular. They consist
of streaming particles, each, according to Professor J. J. Thomson,
of about one-thousandth the mass of the hydrogen atom. Others, the
noted 'alpha rays,' are atomic; they are supposed to aggregate into
helium. Finally, the Röntgen variety are ethereal; they are composed
of light-vibrations reduced in scale, and augmented correspondingly in
frequency.
What is most remarkable is that these various forms of activity give
rise, by different means, to very much the same results. They are, in
fact, distinguishable only by careful observation. They possess in
common, though not to the same degree, the faculties of penetrating
opaque matter, of impressing sensitive plates, of evoking fluorescence;
while under the impact of cathode and Röntgen rays, as well as of
ultra-violet light, insulated electric charges leak away and evanesce.
There is, however, one clear note of separation between cathodic and
X rays in the sensibility of the former, and the indifference of
the latter, to magnetic influence. Thus alone, it would appear, is
electrified matter set apart from what we call ether. A magnet acts
only upon bodies carrying an electric charge; so that, if flying
corpuscles could be obtained in a neutral condition, the only tangible
distinction between the various kinds of rays would vanish. But this
is evidently impracticable. Indeed, advanced physicists abolish the
material substratum of the corpuscle, and assign its attributes to
the associated atom of electricity. It is, at any rate, undeniable
that the electrical relations of matter become more intimate as our
analysis of its constitution goes deeper. Ether, electricity, matter,
all seem to merge together in the limit; their differences ultimately
evade definition. So animal and vegetable life appear to coalesce in
their incipient stages, and strike apart with advance towards a higher
perfection.
The various branches of inorganic nature, too, possibly spring from
a common stock. Our powers of discrimination fail to separate them
as we trace them downward; but that may be because of the inadequacy
of the guiding principles at our command. A larger synthesis is
demanded for the harmonizing of multitudinous facts, at present
grouped incongruously, or left in baffling isolation; and it is
rendered increasingly difficult of attainment by the continual growth
of specialization. Year by year details accumulate, and the strain of
keeping them under mental command becomes heavier; yet what _can_ be
known _must_, in its essentials, be known as a preliminary to extending
the reign of recognised law in Nature.
Sooner or later, nevertheless, the wealth of novel experience recently
acquired will doubtless be turned to the fullest account. Just now,
we can grasp only tentatively its far-reaching import. That it bears
profoundly on the hoary problem of the genesis of visible things is
sufficiently obvious. The questions of what matter is, and of how it
came to be, have been cleared of some of the metaphysical cobwebs
involving them _ab antiquo_, and insistently crave definite treatment
by exact methods. We should, indeed, vainly aspire to reach--or to
comprehend, even if we could reach--an absolute beginning. To quote
Clerk Maxwell's words: 'Science,'[60] he wrote, 'is incompetent to
reason upon the creation of matter itself out of nothing. We have
reached the utmost limit of our thinking faculties when we have
admitted that, because matter cannot be eternal and self-existent, it
must have been created.' The discovery that atoms disintegrate into
corpuscles does not, then, bring us any nearer to the heart of the
mystery; but it is eminently suggestive as regards secondary processes.
Acquaintance with ultra-atomic matter, begun within the narrow
precincts of 'Crookes's tubes,' has advanced rapidly since 'radiology'
took its place among the sciences. For, from the time when Becquerel
first saw a plate darkened by the photogenic projectiles of uranium,
and Madame Curie sifted radium from the refuse of the mines of
Joachimsthal, the lines of proof steadily converged towards the
conclusion that chemical atoms are not only divisible, but that their
decay progresses spontaneously, irresistibly, in fire, air, earth, and
water, as part of the regular economy of Nature.
To explain further. Radio-active bodies are composed--according to
Rutherford's plausible hypothesis--of atoms in unstable equilibrium.
The gradual changes incidental to their own internal activities
suffice to bring about their disruption. And their explosive character
is obviously connected with unwieldy size, since uranium, thorium,
and radium, the three substances pre-eminent for radio-activity,
possess the highest atomic weights known to chemistry. The precarious
balance, then, of each of these complex, though infinitesimally
small systems is successively overthrown, regardless of external
conditions or environment, their constituent parts being hurled abroad
with the evolution of an almost incredible amount of energy. Their
products include cathode-rays; matter in the 'fourth state,' matter
a thousand times finer than hydrogen, is ejected in torrents from
the self-pulverized atoms of radium. Moreover, the issuing rays are
equivalent to currents of negative electricity. Each corpuscle bears
with it an electron, or is itself an electron, for the choice between
the alternatives is open. In either case, we are confronted with
matter apparently in its ultimate form; and to that form ordinary,
substantial bodies tend to become reduced. Electrons may fairly be
called ubiquitous. They occur in flames, near all very hot masses,
wherever ultra-violet light impinges on a metallic surface;[61] they
are freely generated by Röntgen and cathode-rays; they are the agents
of electrical transmission in conductors.
Everywhere throughout the universe, atoms are thus in course of
degradation into corpuscles. But no information is at hand as to
the scene or mode of their reconstitution. The waste and decay are
patent; the processes of compensation remain buried in obscurity.
Indeed, Sir William Crookes anticipates the complete submergence,
at some indefinitely remote epoch, of material substance in protyle,
the 'formless mist' of chaos. He assumes an identity between the past
state and the future, leaving, however, the present unexplained. The
break-up of matter, in fact, does not render its construction the
more intelligible. Running-down is an operation of a different order
from winding-up. It is an expenditure of a reserve of force. It needs
no effort; it accomplishes itself. But to create the reserve for
expenditure demands foresight and deliberate exertion; it implies a
designed application of power.
Now each atom is a storehouse of energy, representing the force
primitively applied to reduce some thousands of free electrons to the
bondage of a harmoniously working system. Its disruption is accompanied
by the dissipation of the energy previously accumulated in it; and that
atomic systems are not calculated for indefinite endurance is one of
the most surprising of modern discoveries. The secret of their original
construction is, none the less, impenetrable. That they are composed
of protyle--that their clustering members are corpuscles moving under
strong mechanical control--is more than probable. And the law of order
adumbrated by what are called the 'periodic' relations of the chemical
elements shows that their concourse was very far from being fortuitous.
But beyond this point there is no holding-ground for distinct thought.
We are ignorant, too, whether the process of building matter out of
protyle is at present going on, or was completed once for all in the
abysmal fore-time, decay being now definitive. Nor is it likely that
we shall ever succeed in capturing with recognition a brand-new atom
freshly minted for cosmical circulation.
FOOTNOTES:
[Footnote 52: First introduced by Basilius Valentinus. See Fowler's
edition of the _Novum Organum_, p. 576, note.]
[Footnote 53: Thus recurring, as Mr. Fowler remarked (_loc. cit._), to
Geber's earlier view.]
[Footnote 54: _Dictionary of National Biography_, vol. xlvi., p. 426.]
[Footnote 55: Crookes, _Philosophical Transactions_, vol. clxx., p.
163.]
[Footnote 56: J. J. Thomson, _The Discharge of Electricity through
Gases_, p. 195; _Philosophical Magazine_, vol. xliv., p. 311.]
[Footnote 57: _Science_, June 26, 1903.]
[Footnote 58: _Proceedings of the Chemical Society_, March 2, 1888.]
[Footnote 59: _Times_, March 30, 1888.]
[Footnote 60: _Encyclopædia Britannica_, article 'Atom.']
[Footnote 61: Fleming, _Proceedings Royal Institution_, vol. xvii., p.
169.]