seized with spasms; but the judge told me that, fifteen years before,
an Italian doctor had come through their country making marvelous
cures. When he arrived at Miraflores there was a _rabioso_ in the jail
who was so badly afflicted and so long-lived that the judge had
ordered him to be shot. When the Italian doctor heard this, however,
he asked permission to try an experiment on the man. This being
granted, he had the patient lassoed, dragged to the river, and held
under water until he was apparently drowned. After the _rabioso_ was
full of water, the doctor rolled him on a barrel and resuscitated
him; then he gave him some medicine which cured him. Cipriano Fisher
told me that he had cured a valuable bulldog of rabies by this same
method, using the bitter juice of the _pitahaya_, a species of cactus,
for medicine. This crude means of alleged cure is unique, and seems
based on the theory that the antipathy of rabid animals to water,
implied in the name hydrophobia, is the cause of their death, and
partial drowning, therefore, a cure.
Rabies is extremely prevalent at times in certain districts of the
Cape region. McLellan says it does not occur north of the tropic of
Cancer--that is, of La Paz and Todos Santos--and it is hardly known in
the thickly populated district about San José del Cabo, but at Cape
San Lucas, and especially also along the base of the mountains near
Miraflores and Agua Caliente, where it is very hot and dry, rabid
animals are greatly to be feared. While collecting in these mountains
I passed several good ranches which had been deserted because, as my
guide said, stock could not be raised there successfully on account of
the _rabia_.
This man had worked as a _ranchero_ or stock herder for two years on
one of these ranches, and had been obliged at one time to kill eleven
cattle and seven sheep and goats in two weeks on account of their
having rabies. It was part of his duty to follow up rabid coyotes,
foxes, skunks, and wild cats when he saw them or heard their peculiar
cry, and shoot them before they bit the stock. But he assured me very
gravely that he preferred to work in the valley for less wages rather
than have charge of Chollalito rancho; and when we camped there for a
night he slept on top of the pack boxes, with his bare feet wrapped in
blankets and a _serape_ over his head, and reverently pulled out the
blessed rag he wore around his neck, in order to more surely protect
himself against the rabid skunks and coyotes. There is, however, very
little danger in traveling through this interesting country. Cases of
hydrophobia are comparatively rare, and some scientists who have
collected in Baja California have even denied its existence there. But
with the traveler, as with the native, there remains the vague,
constant, but unrealized expectation of seeing some raging coyote come
tearing through the cactus, or of having his toe bitten in the middle
of the night as he sprawls in the heat and darkness.
* * * * *
PROFESSOR WELLDON, in the British Association, expressed his
sense of the intellectual insolence of those who presume to say,
notwithstanding our ignorance of animal characters, that because
a characteristic seems to us minute and without importance, it is
therefore without importance to the animal. Until we know the
function of the animal throughout, and can picture its
physiological processes thoroughly, we have no right to say, _a
priori_, that this or that feature is of no use.
THE SENSE OF COLOR.
BY M. ANDRÉ BRACCHI.
When the different rays of the solar spectrum strike the eye
separately they each produce a particular characteristic and
subjective impression, which is called color. Ingenious theories have
been set forth by physiologists, like Young, Helmholtz, Hering, and
others, to explain the perception of colors by our eye, but the
problem still awaits solution, and is not likely to be explained from
that side, because it is rather psychical. The laws regulating the
perception of colors are not physiological; we perceive only
relations. We know that the sense of color may be modified
independently of that of light and of space. Two phases may be
distinguished in its evolution. Every light, whether chromatic or not,
produces a simple luminous impression on the retina--a simple
excitation of the optic nerve, without being analyzed by it. In the
second phase the brain, the psychic center of color, intervenes. There
may obviously be considerable differences between persons in the
interpretation of what we call colors, and we may judge that there is
an education of this psychical center, and that it is an important
matter.
Different as the ways of interpreting a sensation of color may be,
there are still some fundamental ideas in the matter which painters,
for example, do not all observe. Some, like the impressionists,
exaggerate them, and others neglect them. Which of these are wrong?
and which right? are questions we are not concerned with, our purpose
being to show that many of the phenomena of color, shade, sources of
light, etc., escape a large proportion of persons unless they are
attentive observers. If we visit the exhibitions of the impressionists
we shall be entertained at the criticisms we hear over the canvases of
such painters as Renoir and Monet; youths who have just come out of
the drawing school declaring that their master never taught them to
put blue on a face, and that in Nature all shadows are gray or black,
and none red or violet; and we should astonish a great many people if
we should say that a white robe should never be painted in a portrait
picture with white lead alone. "All skies are blue, all trees are
green, all pantaloons are red," said a celebrated painter who was
trying to show how the habit of seeing a colored object in a certain
way prevented one from perceiving the different colors that might be
applied to it. We recollect the trouble of a brave youth who, having
sat for his portrait to a celebrated painter, was distracted at
perceiving green in the reflections of the hair of his likeness. Yet
there are in Nature shadows that are blue and reflections that are
green, and if we do not see them habitually it is because we do not
give sufficient attention to them.
A common division of the spectrum is into warm and cold colors. The
warm colors are red, yellow, orange, and yellow-green; the cold colors
are violet, blue, green, and blue-green. This is not an arbitrary
division, but answers to a fact of experience which passes from our
physical to our moral impressions, and may cause in us feelings of
comfort or uneasiness, joy, sadness, or moral depression. Some persons
are influenced by the gray-colored sky, others are gay when the day is
bright. It is a current expression that the color of the southern
landscape is warm. Goethe said that blue caused him to feel cold.
The terms warm and cold are technical expressions in the arts. A color
tone is cooled by putting blue in it, and warmed by adding red or
yellow. "This practice is not arbitrary," says M. F. Bracquemond in
his book on Design and Color; "it copies the colored aspects which
natural light imposes on all imitation that seeks to realize the
colored and factitious light of painting. To reach this, art observes
the order according to which the natural lights distribute their
various colored elements, and classes luminous aspects--a process
which it has always observed--into the two categories of warm and
cold. Hence, so far as examples come to us, this contrast is easy to
verify; at the Louvre, for example, in works from Pompeii, and in
those of all the masters." Preyer relies upon this division of colors
into warm and cold for a comparison of chromatic sensations with
thermic, and for supposing that the color sense is developed from the
sense of temperature. Chromatic sensitiveness to this author is only a
special case of thermic sensitiveness limited to the retina. Darwin's
ideas were evidently the same; the whole human body was a sort of
retina capable of improvement; we may, it is true, suppose with Lord
Kelvin that "there is absolute continuity between the perception of
heat by the retina of the eye and its perception by means of the
tissues and nerves."
A very elementary experiment will easily enable us to recognize these
different qualities of colors. Set a lighted candle on a table near a
window; there are then two sources of light--the daylight, blue and
cold, and the light of the candle, orange-red and warm. Cast a shadow
on the white paper by holding a pencil straight up. The shadows cast
by the candle will be blue to a degree that no one can mistake it, a
greenish blue. Placing the pencil between the window and the candle
and looking at the shadows, we have, first, the blue shadow of the
candle, and then the shadow projected by the cold daylight. The color
of the last, though perhaps less evident than the other, is an
orange-yellow, of rich, warm tone.
From this little experiment we may conclude that a warm light provokes
a cold shadow, a cold light a warm shadow, and that the color of the
shadow is complementary to that of the light. In the experiment,
daylight was the source of the cold light. Let us now take a third
source of light, warmer than that of the candle, the flame produced by
burning alcohol and salt--a very warm, deep orange light, which makes
the light of the candle seem cold and its blue shadows appear yellow,
while its own shadows are blue.
We recently observed a very striking example of these warm and cold
appearances of light; it was at the theater: a beam of red light shone
brightly upon an actor, whose shadow was absolutely green. Some of the
people around us were astonished at the phenomenon, which they could
perceive very plainly. Phenomena of this kind are produced every
instant in a nature illuminated by the sun; nearly all the shadows are
colored in hues which we can distinguish with a little attention where
the unpracticed eye sees nothing but gray. Thus in a mountainous
country, exposed to the warm light of the sun, the mountains in the
horizon appear blue through the haze; then, as evening draws on, the
sun appears a deeper orange, more reddish, while the sky seems green
by contrast, and the red rays of the sun falling on the mountains turn
them violet, in those beautiful tints which give so much glory to
those countries of large shadows and bright lights.
However intense the light of day may be, it is therefore always
colored, and gives those colored shadows which painters do not always
observe. The painter, in fact, should make an analysis of the complex
light around him, and should repeat the result in synthesis on his
canvas. Upon hardly any other condition can he represent the
transparency of the atmosphere, or the luminosity of a subject or a
landscape. These colored shadows are not, therefore, false colors, as
often seems to be believed, or optical illusions; they are really
existent, but our eyes are hardly ever practiced enough to discern
them; we are deficient in education of the color sense. This education
is not hard to attain. There are persons who have special aptitudes
and are consequently remarkable colorists, just as some persons have
an admirably organized ear for music; but, besides these, it is
possible for all persons endowed with the faculty of observing and
capable of attention to acquire with considerable rapidity the faculty
of discerning colors, where they at present hardly see anything but
confused gray masses. (The epithet gray, we may observe, is used as
applied to many things the color of which is not susceptible of exact
determination.) Such attentive observation of colors is, however,
attended with some danger to painters. Every person prefers some one
color, is influenced by a particular shade. When we examine the works
of the painters we see that there are many differences in the way of
seeing. Some see blue, red, green; others see clear, others obscure.
In the analysis of a complex color it happens that there is sometimes
an auto-suggestion. Where there is a hardly defined violet, the
painter will exaggerate it on his canvas, and will be obliged, in
order to keep up the right tone, to increase the intensity of the
colors next to it. Hence arises a common error with painters, who
start with a true principle, but are not able to apply it properly,
and give their picture a tonic violet, green, or yellow, beyond all
reason.--_Translated for the Popular Science Monthly from the Revue
Scientifique._
SKETCH OF THOMAS EGLESTON.
BY PROF. DANIEL S. MARTIN.
As a general rule, the work of the scientist is not of a kind to
attract conspicuous notice from the public, especially in great
cities, filled and thrilled with commercial and political activity;
and so it comes to pass that men of rare attainments and untiring
energy, in the highest walks of life and thought, may spend their
whole life-time in such an environment, and be scarcely known outside
of a limited circle of kindred minds. They may confer lasting benefits
on the community, render important services to the whole country, and
be widely known and honored in other lands, and yet receive but little
general recognition in the place of their abode.
Such a man, in such a community, is Prof. THOMAS EGLESTON, of the city
of New York. He has been too busy and too modest to seek prominence in
the public eye, and his scientific work has been of a kind that does
not lend itself readily to popular lectures or startling
announcements; but as a mineralogist, a metallurgist, and a mining
engineer, and as the planner and founder of the great School of Mines
of Columbia University, he has made a deep and permanent impress on
the history of science in the United States.
Professor Egleston is of New England stock, his ancestors having been
among the first settlers of Dorchester, Massachusetts, in 1635. Thence
they came by a toilsome and perilous journey to Connecticut, and
founded Windsor, which was thenceforward their home, and whence his
father came to New York. The removal to Connecticut arose from a
desire for greater freedom of life and worship than they found in
Massachusetts; and Professor Egleston has been deeply interested in
studying the little-known records of this movement, and the influence
which it exerted, as an almost unwritten chapter in American history.
He proposes to publish these researches, together with much other
material relating to our colonial history, in which he is an
enthusiastic student.
He was born in New York, on December 9, 1832. As a boy he took
considerable interest in certain aspects of science, and at the age of
thirteen had gathered a collection of minerals and rocks. He attended
Yale College, and in the later years of his course took special
elective work in chemistry. After graduating there in 1854, he was for
a time an assistant to Prof. Benjamin Silliman, Jr. Subsequently he
went abroad, partly for his health, and was advised to spend some time
in Paris. With no special professional purpose, but from a general
desire to improve his time, he began attending lectures on geology and
chemistry at the Jardin des Plantes, under D'Orbigny (a brother of the
eminent writer) and Hilgard, and he worked with much energy in the
laboratories of those departments at the Jardin. He thus attracted the
attention of some of the faculty of the École des Mines, who offered
him larger facilities in that institution, which he at once accepted.
After much very interesting study in the paleontological laboratory
there, he decided to go regularly through the entire course, and
accomplished that purpose with notable success and honor, graduating
in 1860. He had worked as an assistant in every laboratory of the
school, and in the summers had traveled through much of France,
becoming familiar with its geology, mineral resources, mining works
and processes, and gaining a mastery at first hand of all branches of
those subjects. Those years were to him full of interest and
enjoyment; friendships were formed that have enriched his whole life;
and in it all the man was being remarkably prepared for the work of
developing those forms of science and of industrial progress in our
own country. Professor Egleston has always retained a strong feeling
of attachment toward the École des Mines, which has likewise been
warmly reciprocated. He has shown his interest by two gifts to the
institution, of five thousand dollars each.
Returning hither in 1861, just as the war cloud was darkening over
the land, he received almost immediately an appointment at
Washington, to take charge of the mineralogical collections and
laboratory of the Smithsonian Institution. After two years there he
conceived the purpose that determined his whole career, and has so
greatly influenced both American science and American mineral
development--that of a school of mines at New York.
At that time there were, indeed, in this country schools of science,
well organized and well equipped--the Sheffield School at Yale, the
Lawrence Foundation at Harvard, the Rensselaer Polytechnic Institute
at Troy, and others. But their scope was rather general in character,
and there was no institution planned and arranged with distinct
reference to mining and metallurgy as its main subjects. Mr. Egleston,
as he was then known, saw and felt this lack, and planned to supply
it.
There is not space here to detail the circumstances under which he was
led to prepare, in 1863, the Plan for a School of Mines in New York;
but the modest little outline then drawn up and printed has been
exceedingly rich in results. It was taken up with interest by certain
leading trustees of Columbia College, as it was then called,
especially by the late George T. Strong. The president, the late Dr.
Charles King, and a majority of the board, favored the experiment, for
so it was regarded, and arrangements were finally made to begin it in
the autumn of the next year, in limited quarters in the old college
building on Forty-ninth Street, and with provision for but a small
number of students--not over twenty. Part of the instruction was to be
given by members of the existing college faculty; and three new
professors were appointed to special chairs for the school, to be
compensated wholly by fees therefrom. These were, Professor Egleston,
mineralogy and metallurgy; Prof. Francis Vinton, mining engineering;
and Dr. C. F. Chandler, chemistry.
Meanwhile, in June, 1864, President King was succeeded by the late Dr.
Barnard, whose strong interest in science made him a warm supporter of
the school. Already some prominent people were impressed with the
value of such a movement, and disposed to aid it. A fine collection of
minerals was purchased and presented by Mr. Strong, and another was
given by Mr. Gouverneur Kemble.
On the opening day, November 15, 1864, the number of applicants was
far beyond expectation and provision; the school was found to respond
to a need and a demand that had not been suspected; it was a success
from the first. In a year or two it had become an institution of
recognized importance; ample quarters were provided for it in a large
building, formerly a manufactory, on the Fourth Avenue side of the
college block, and important additions were made to its corps of
instructors--particularly the eminent geologist, Dr. J. S. Newberry,
of Cleveland, Ohio, whose noble geological collection was deposited
and used in the School of Mines, and whose breadth and power and
personal magnetism so profoundly influenced scientific interest and
progress in the city of New York for more than twenty years.
Such was the beginning of the school; its career has been one of
unbroken growth and increasing influence. After some ten years it was
found needful to take down the plain old transformed factory and erect
a new building on its site, with larger space and improved facilities.
Fifteen years later Columbia College was removed to its new site on
the Morningside Heights, where now the School of Mines is installed in
stately fireproof structures, wherein its great accumulated treasures
of collections, apparatus, models, and varied appliances of
instruction are safely and permanently housed.
The influence of this school upon science in New York city has been
incalculable. Only those who have lived in touch with the scientific
life of the metropolis during the period since the close of the civil
war can appreciate the change that has taken place in public feeling
regarding science, or can recognize how largely that change is due to
the existence of such an institution, and to the presence of such a
body of strong and able professors, in constant and active
co-operation in the interest of science. The school attracted notice
from the first, abroad as well as throughout this country. In 1871,
seven years from its opening, a writer in the North American Review
characterized it as "already more scientific than Freiberg, more
practical than Paris," and emphasized its influence both upon science
and upon mining interests in the United States, pointing out that the
literature pertaining to mines and their working had been very limited
in the English language, and that the instruction in the school had to
be chiefly given by lectures; but that these courses would gradually
develop into a literature.
These suggestions have been fully justified by the results of the last
quarter century. The vast development of our mineral resources has
been largely under the direction of graduates of this school. Hundreds
of them are to-day in important positions of scientific trust, not
only throughout our own country but in South and Central America,
Australia, China, Japan, and even Europe itself. The lectures of the
professors, and the articles constantly published in the School of
Mines Quarterly, have indeed given us a literature of the subject in
English. The local influence in the city has been great, upon
scientific education in secondary schools, and upon general public
sentiment; while in Columbia University the experiment has become one
of its finest departments and an element of its greatest strength.
Rarely is it given to a man to see in his life-time so great a result
from the plans and the labors of his earlier years.
Of the many forms of scientific activity which have engaged Professor
Egleston during his busy life, only the briefest mention can be made.
He was one of the founders of the American Institute of Mining
Engineers, was thrice its vice-president, and was chosen president in
1886; and he has published over one hundred articles in its
Transactions. He was one of the founders of the American Metrological
Society, and of the societies of Mechanical Engineers and of
Electrical Engineers, and a member of the society of Civil Engineers
and of the Iron and Steel Institute of Great Britain. In the New York
Academy of Sciences he was active for many years, and held the
vice-presidency from 1869 to 1881. In 1866 Professor Egleston was
associated with the Agricultural and Geological Survey of the Union
Pacific Railroad; in 1868 was appointed a United States Commissioner
to examine the fortifications of the coast; and in 1873 was one of the
jurors for the International Exposition at Vienna. From Princeton and
Trinity Colleges he received, in 1874, the degrees of Ph. D. and LL.
D., respectively, and from the Government of France the rank of a
Chevalier of the Legion of Honor in 1890, and the exceptional rank of
"Officier" in 1895.
His papers, published either separately or in the proceedings of the
several engineering societies above mentioned, the Annals of the New
York Academy of Sciences, the School of Mines Quarterly, etc., cover a
wide range of subjects connected with mineralogy, metallurgy, and
mining operations. In mineralogy he was especially devoted to
crystallography, and his noble private collection was gathered and
arranged with relation to that department. Besides his strictly
metallurgical articles and treatises, he has dealt with such topics as
rails, in relation to accidents; furnaces and their construction;
fire-brick and refractory substances; slags and their utilization,
etc.; the decay of building stones, in connection with the Obelisk;
technical education, manual training, and improvement in the
conditions of workingmen in mining and metallurgical occupations.
His chief published works are The Metallurgy of Gold, Silver, and
Mercury in the United States, two large volumes, 1887 and 1890, and
his Lectures on Mineralogy, to which may be added his Tables for the
Determination of Minerals, Metallurgical Tables on Fuels, Iron, and
Steel, diagrams and comparisons of crystals and crystal notation,
tables of production of many of the metals, report on the Union
Pacific Railroad survey of 1868, and many others.