smaller fragment; and he soon found that he could remove slice after
slice of it, until there was no trace of the original prism, but in
place of it a rhomboid, {179} perfectly similar to Iceland spar, and
lying in the middle of what was the original prism. This fact seemed
to him very important. From it he began the development of a theory of
crystallization, using this observation as the key. Before this time
it had been hard for students of mineralogy to understand how it was
that substances of the same composition might yet have what seemed to
be different crystalline forms. Calcspar, for instance, might be found
crystallized in forms, apparently, quite at variance with one another.
By his studies, however, Hauey was able to determine that whenever
substances of the same composition crystallized, even though the
external form of the crystals seemed to be different, all of them were
found to have the same internal nucleus. Whenever the mineral under
observation was chemically different from another, then the nucleus
also had a distinctive character; and so there came the law that all
substances of the same kind crystallized in the same way,
notwithstanding apparent differences. Indeed, one of the first results
of this law was the recognition of the fact that when the crystalline
forms of two minerals were essentially different, then, no matter how
similar they might be, there was sure to be some chemical difference.
This enabled Hauey to make certain prophecies with regard to the
composition of minerals.
A number of different kinds of crystals had been classed together
under the name of {180} heavyspar. Some of these could not, by the
splitting process, be made to produce _nuclei_ of similar forms, and
the angles of the crystals were quite different. Hauey insisted that,
in spite of close resemblances, there was an essential distinction in
the chemical composition of these two different crystalline
formations; and before long careful investigation showed that, while
many of the specimens called heavyspar contain barium, some of them
contain a new substance--strontium--which had been very little
studied heretofore. This principle did not prove to be absolute in its
application; but the amount of truth in it attracted attention to the
subject of crystallography because of the help which that science
would afford in the easy recognition of the general chemical
composition of mineral substances. The most important part of Hauey's
work was the annunciation of the law of symmetry. He emphasized the
fact that the forms of crystals are not irregular or capricious, but
are very constant and definite, and founded on absolutely fixed and
ascertainable laws. He even showed that, while from certain
crystalline nuclei sundry secondary forms may be derived, there are
other forms that cannot by any possibility occur. Any change of
crystalline form noticed in his experiments led to a corresponding
change along all similar parts of the crystal. The angles, the edges,
the faces, were modified in the same way, at the same time. All these
elements of mensuration within the crystal Hauey thought could be
indicated by rational coefficients.
{181}
Crystallography, however, did not absorb all Hauey's attention. He
further demonstrated his intellectual power by following out other
important lines of investigation that had been suggested by his study
of crystals. It is to him more than to any other, for instance, that
is due the first steps in our knowledge of pyro-(or thermo-)
electricity. Mr. George Chrystal, professor of mathematics at the
University of St. Andrews, in the article on electricity written for
the ninth edition of the Encyclopedia, says it was reserved for the
Abbe Hauey in his Treatise on Mineralogy to throw a clear light on this
curious branch of the science of electricity.
To those who are familiar with the history of the development of this
science it will be no surprise to find a clergyman playing a prominent
role in its development. During the days of the beginning of
electricity many ecclesiastics seem to have been particularly
interested in the curious ways of electrical phenomena, and as a
consequence they are the original discoverers of some of the most
important early advances. Not long before this, Professor Gordon, a
Scotch Benedictine monk who was teaching at the University of Erfurt,
constructed the first practical electrical machine. Kleist, who is one
of the three men to whom is attributed the discovery of the principle
of storing and concentrating electricity, and who invented the Leyden
Jar, which was named after the town where it was first manufactured,
was also a member of a Religious Order. As {182} we have already
stated, Dirwisch, the Premonstratensian monk, set up a
lightning-conductor by which he obtained sparks from the clouds even
before our own Franklin.
Abbe Hauey was only following a very common precedent, then, when he
succeeded by his original research in setting the science of
pyro-electricity firmly on its feet. It is true, others before him had
noted that substances like tourmaline possessed electrical properties.
There is even some good reason for thinking that the _lyncurium_ of
the ancients which, according to certain of the Greek philosophers,
especially Theophrastus, who seems to have made a close study of the
subject, attracted light bodies, was really our modern tourmaline. In
modern times the Dutch found this mineral in Ceylon and, because it
attracted ashes and other light substances to itself, called it
_aschentriker_--that is, attractor of ashes. Others had still further
experimented with this curious substance and its interesting
electrical phenomena. It remained for Abbe Hauey, however, to
demonstrate the scientific properties of tourmaline and the relations
which its electrical phenomena bore toward the crystalline structure
of the mineral. He showed that the electricity of tourmaline decreases
rapidly from the summits or poles toward the middle of the crystal. As
a matter of fact, at the middle of the crystal its electrical power
becomes imperceptible.
He showed also that each particle of a crystal {183} that exhibits
pyro-electricity is itself a source of the same sort of electricity
and exhibits polarity. His experimental observations served to prove
also that the pyro-electric state has an important connexion with the
want of symmetry in the crystals of the substances that exhibit this
curious property. In tourmaline, for instance, he found the vitreous
charge always at the summit of the crystal which had six faces, and
the resinous electricity at the summit of the crystal with three
faces.
His experiments soon showed him, too, that there were a number of
other substances, besides tourmaline, which possessed this same
electrical property when subjected to heat in the crystalline stage.
Among these were the Siberian and Brazilian topaz, borate of magnesia,
mesotype, sphene, and calamine. In all of these other pyro-electrical
crystals, Hauey detected a corresponding deviation from the rules of
symmetry in their secondary crystals to that which occurs in
tourmaline. In a word, after he had concluded his experiments and
observations there was very little left for others to add to this
branch of science, although such distinguished men as Sir David
Brewster in England were among his successors in the study of the
peculiar phenomena of pyro-electricity.
It may naturally enough be thought that, born in the country, of poor
parents, and compelled to work for his living, Hauey would at least
have the advantage of rugged health to help him in his {184} career.
He had been a delicate child, however; and his physical condition
never improved to such an extent as to inure him to hardships of any
kind. One of his biographers has gone so far as to say that his life
was one long malady. The only distraction from his almost constant
suffering was his studies. Yet this man lived to be nearly eighty
years of age, and accomplished an amount of work that might well be
envied even by the hardiest.
In the midst of his magnificent success as a scientist, Hauey was
faithful to all his obligations as a priest. His name was known
throughout Europe, and many of the scientific societies had considered
that they were honoring themselves by conferring titles, or degrees,
upon him; but he continued to be the humble, simple student that he
had always been.
At the beginning of the Revolution, Abbe Hauey was among the priests
who refused the oath which the Republican government insisted on their
taking, and which so many of them considered derogatory to their duty
as churchmen. Those who refused were thrown into prison, Hauey among
them. He did not seem to mind his incarceration much, but he was not a
little perturbed by the fact that the officers who made the arrest
insisted on taking his precious papers, and that his crystals were all
tossed aside and many of them broken. For some time he was kept in
confinement with a number of other members of the faculty of the
University, mainly {185} clergymen, in the Seminary of St. Firmin,
which had been turned into a temporary jail.
Hauey did not allow his studies to be entirely interrupted by his
imprisonment. He succeeded in obtaining permission to have his
cabinets of crystals brought to his cell, and he continued his
investigation of them. It was not long before powerful friends, and
especially his scientific colleague, Gregory St. Hilaire, interested
themselves in his case, and succeeded in obtaining his liberation.
When the order for his release came, however, Hauey was engaged on a
very interesting problem in crystallography, and he refused to
interrupt his work and leave the prison. It was only after
considerable persuasion that he consented to go the next morning. It
may be added that only two weeks later many from this same prison were
sent to the guillotine.
It is rather remarkable that the Revolutionary government, after his
release, did not disturb him in any way. He was so much occupied with
his scientific pursuits that he seems to have been considered
absolutely incapable of antagonizing the government; and, as he had no
enemies, he was not denounced to the Convention. This was fortunate,
because it enabled him to pursue his studies in peace. There was many
another member of the faculty of the University who had not the same
good fortune. Lavoisier was thrown into prison, and, in spite of all
the influence that could be brought to bear, the great discoverer of
oxygen met his death by the guillotine. At least {186} two others of
the professors in the physical department, Borda and De Lambre, were
dismissed from their posts. Hauey, though himself a priest who had
refused to take the oath, and though he continued to exercise his
religious functions, did not hesitate to formulate petitions for his
imprisoned scientific friends; yet, because of his well-known
gentleness of character, this did not result in arousing the enmity of
any members of the government, or attracting such odious attention as
might have made his religious and scientific work extremely difficult
or even prevented it entirely.
Notwithstanding the stormy times of the French Revolution and the
stirring events going on all round him in Paris, Hauey continued to
study his crystals in order to complete his observations; and then he
embodied his investigations and his theories in his famous "Treatise
on Crystallography." This attracted attention not only on account of
the evident novelty of the subject, but more especially because of the
very thorough method with which Hauey had accomplished his work. His
style, says the historian of crystallography, was "perspicuous and
elegant. The volume itself was noteworthy for its clear arrangement
and full illustration by figures." In spite of its deficiencies, then
deficiencies which must exist in any ground-breaking work--this
monograph has had an enduring influence. Some of the most serious
flaws in his theory were soon brought to light because of the very
stimulus afforded by his investigations.
{187}
As to the real value of his treatise, perhaps no better estimate can
be formed than that given by Cuvier in his collection of historical
eulogies (Vol. III, p. 155): "In possession of a large collection, to
which there flowed from all sides the most varied minerals, arranged
with the assistance of young, enthusiastic, and progressive students,
it was not long before there was given back to Hauey the time which he
had apparently wasted over other things. In a few years he raised up a
wondrous monument, which brought as much glory to France as it did
somewhat later to himself. After centuries of neglect, his country at
one bound found itself in the first rank in this department of natural
science. In Hauey's book are united in the highest degree two qualities
which are seldom associated. One of these is that it was founded on an
original discovery which had sprung entirely from the genius of its
author; and the other is that this discovery is pursued and developed
with almost unheard-of persistence down even to the least important
mineral variety. Everything in the work is great, both as regards
conception and detail. It is as complete as the theory it announces."
It was not surprising, then, that, after the death of Professor
Dolomieu, Hauey should be raised to the chair of mineralogy and made
director of that department in the Paris Museum of Natural History.
Here he was to have new triumphs. We have already said that his book
was noted for the elegance of its style and its perspicuity. {188} As
the result of this absolute clearness of ideas, and completeness and
simplicity of expression, Hauey attracted to him a large number of
pupils. Moreover, all those interested in the science, when they came
in contact with him, were so charmed by his grace and simplicity of
manner that they were very glad to attend his lectures and to be
considered as his personal friends. Among his listeners were often
such men as La Place, Berthollet, Fourcroy, Lagrange and Lavoisier.
It was not long before honors of all kinds, degrees from universities
and memberships in scientific societies all over Europe, began to be
heaped upon Hauey. They did not, however, cause any change in the
manners or mode of life of the simple professor of old times. Every
day he continued to take his little walks through the city, and was
very glad to have opportunity to be of assistance to others. He showed
strangers the way to points of interest for which they inquired,
whenever it was necessary, obtained entrance cards for them to the
collection; and not a few of those who were thus enabled to take
advantage of his kindness failed to realize who the distinguished man
was to whom they owed their opportunities. His old-fashioned clothing
still continued to be quite good enough for him, and his modest
demeanor and simple speech did not betray in any way the distinguished
scientist he had become.
Some idea of the consideration in which the {189} Abbe Hauey was held
by his contemporaries may be gathered from the fact that several of
the reigning monarchs of Europe, as well as the heirs apparent to many
thrones, came at some time or other to visit him, to see his
collection, and to hear the kindly old man talk on his hobby. There
was only one other scientist in the nineteenth century--and that was
Pasteur, toward the end of it--who attracted as much attention from
royalty. Among Hauey's visitors were the King of Prussia, the Emperor
of Austria, the Archduke John, as well as the Emperor of Russia and
his two brothers, Nicholas and Michael, the first of whom succeeded
his elder brother, Alexander, to the throne, and half a century later
was ruling Russia during the Crimean War. The Prince Royal of Denmark
spent a portion of each year for several years with Hauey, being one of
his intimates, who was admitted to his room while he was confined to
his bed, and who was permitted to share his personal investigations
and scientific studies.
His most striking characteristic was his suavity toward all. The
humblest of his students was as sure to receive a kindly reception
from him, and to have his difficulties solved with as much patience as
the most distinguished professor in this department. It was said that
he had students of all classes. The attendants at the normal school
were invited to visit him at his house, and he permitted them to learn
all his secrets. When they came to him for a whole {190} day, he
insisted on taking part in their games, and allowed them to go home
only after they had taken supper with him. All of them looked upon him
as a personal friend, and some of them were more confidential with him
than with their nearest relatives. Many a young man in Paris during
the troublous times of the Revolutionary period found in the good Abbe
Hauey not only a kind friend, but a wise director and another father.
It is said that one day, when taking his usual walk, he came upon two
former soldiers who were just preparing to fight a duel and were on
their way to the dueling ground. He succeeded in getting them to tell
him the cause of their quarrel, and after a time tempted them to come
with him into what I fear we should call at the present day a saloon.
Here, over a glass of wine, he finally persuaded them to make peace
and seal it effectually. It is hard to reconcile this absolute
simplicity of character and kindness of heart with what is sometimes
assumed to be the typical, distant, abstracted, self-centered ways of
the great scientist.
Few men have had so many proofs of the lofty appreciation of great
contemporaries. Many incidents serve to show how much Napoleon thought
of the distinguished scholar who had created a new department of
science and attracted the attention of the world to his splendid work
at Paris. Not long after he became emperor, Napoleon named him
Honorary Canon of the {191} Cathedral of Notre Dame; and when he
founded the Legion of Honor, he made the Abbe one of the original
members. Shortly after these dignities had been conferred upon him, it
happened that the Abbe fell ill; and Napoleon, having sent his own
physician to him, went personally to call on him in his humble
quarters, saying to the physician: "Remember that you must cure Abbe
Hauey, and restore him to us as one of the glories of our reign." After
Napoleon's return from Elba, he told the Abbe that the latter's
"Treatise on Crystallography" was one of the books that he had
specially selected to take with him to Elba, to while away the leisure
that he thought he would have for many years. Abbe Hauey's independence
of spirit, and his unselfish devotion to his native country, may be
best appreciated from the tradition that after the return from Elba,
when there was a popular vote for the confirmation of Napoleon's
second usurpation, the old scientist voted, No.
In spite of his constant labor at his investigations, his uniformly
regular life enabled him to maintain his health, and he lived to the
ripe age of over seventy-nine. Toward the end of his career, he did
not obtain the recognition that his labors deserved. After the
Restoration, he was not in favor with the new authorities in France,
and he accordingly lost his position as professor at the University.
The absolute simplicity of life that he had always maintained now
stood him in good stead; and, notwithstanding the {192} smallness of
his income, he did not have to make any change in his ordinary
routine. Unfortunately, an accidental fall in his room at the
beginning of his eightieth year confined him to his bed; and then his
health began to fail very seriously. He died on the 3 June, 1822.
He had shown during his illness the same gentleness and humility, and
even enthusiasm for study whenever it was possible, that had always
characterized him. While he was confined to his bed he divided his
time between prayer, attention to the new edition of his works which
was about to appear, and his interest for the future of those students
who had helped him in his investigations. Cuvier says of him that "he
was as faithful to his religious duties as he was in the pursuit of
his studies. The profoundest speculations with regard to weighty
matters of science had not kept him from the least important duty
which ecclesiastical regulations might require of him." There is,
perhaps, no life in all the history of science which shows so clearly
how absolutely untrue is the declaration so often made, that there is
essential opposition between the intellectual disposition of the
inquiring scientist and those other mental qualities which are
necessary to enable the Christian to bow humbly before the mysteries
of religion, acknowledge all that is beyond understanding in what has
been revealed, and observe faithfully all the duties that flow from
such belief.
{193}
VIII.
ABBOT MENDEL: A NEW OUTLOOK IN HEREDITY.
There is grandeur in this view of life, with its several powers having
been originally breathed by the Creator into a few forms or into one;
and that, while this planet has gone circling on according to the
fixed law of gravity from so simple a beginning, endless forms, most
beautiful and most wonderful, have been and are being evolved.--
Closing sentence of DARWIN'S _Origin of Species_.
{194}
[Illustration: GREGOR MENDEL]
{195}
VIII.
ABBOT MENDEL, [Footnote 14]: A NEW, OUTLOOK IN HEREDITY.
[Footnote 14: The portrait of Abbot Mendel which precedes this
sketch was kindly furnished by the Vicar of the Augustinian
Monastery of Bruenn. It represents him holding a fuchsia, his
favorite flower, and was taken in 1867, just as he was completing
the researches which were a generation later to make his name so
famous. The portrait has for this reason a very special interest as
a human document. We may add that the sketch of Abbot Mendel which
appears here was read by the Very Rev. Klemens Janetschek, the
Vicar of the Monastery, who suggested one slight change in it, so
that it may be said to have had the revision of one who knew him and
his environment very well.]
Scientific progress does not run in cycles of centuries, and as a rule
it bears no relationship to the conventional arrangement of years. As
has been well said--for science a new century begins every second.
There are interesting coincidences, however, of epoch-making
discoveries in science corresponding with the beginning of definite
eras in time that are at least impressive from a mnemonic standpoint,
if from no other.
The very eve of the nineteenth century saw the first definite
formulation of the theory of evolution. Lamarck, the distinguished
French biologist, stated a theory of development in nature which,
although it attracted very little attention {196} for many years after
its publication, has come in our day to be recognized as the most
suggestive advance in biology in modern times.
As we begin the twentieth century, the most interesting question in
biology is undoubtedly that of heredity. Just at the dawn of the
century three distinguished scientists, working in different
countries, rediscovered a law with regard to heredity which promises
to be even more important for the science of biology in the twentieth
century than was Lamarck's work for the nineteenth century. This law,
which, it is thought, will do more to simplify the problems of
heredity than all the observations and theories of nineteenth-century
workers, and which has already done much more to point out the methods
by which observation, and the lines along which experimentation shall
be best directed so as to replace elaborate but untrustworthy
scientific theorizing by definite knowledge, was discovered by a
member of a small religious community in the little-known town of
Bruenn, in Austria, some thirty-five years before the beginning of the
present century.