It is said of Milton that in two short lines of poetry he made four
mistakes in Natural History. He said of a whale:
“At his gills takes in,
And at his trunk lets out a sea.”
Now, in the first place, the whale has no gills; second, he takes in
air instead of water; third, he throws out expired air; fourth, the
water “spouted” is thrown up by the force of expiration, not out of the
animal’s body, but water that may lie between the “blow-hole” and the
surface of the sea.
I am not so sure but Milton made more than four mistakes in these
lines. For whoever starts out on a wrong premise will follow a line of
mistakes continually. Nevertheless, mistakes attentively observed may be
profitable. We learn by mistakes. Unsuccessful experiments are mistakes
of a kind—something wrong in the formula. The first aquarium I tried to
start I made more mistakes than Milton made in his two lines. I made
mistakes the second trial, and the third, and a dozen more times. And
when I have succeeded in some instances, it was by accident, and to-day
I can not tell why I sometimes failed, or why I sometimes succeeded. I
have the consolation, however, of company in this respect. One of the
most successful managers of aquaria says that he would give very much if
he knew how to grow some of the higher marine algæ as one grows plants in
a garden. Occasionally he has succeeded, but he confesses it was not by
skill, but by chance.
I propose, therefore, that for a little while we consider the sea as an
aquarium—a place adapted to the growth of animals and plants. Our subject
is somewhat large, I must confess, but if we can see and understand how
these things live and grow in the ocean we must be able to grow them in
our parks, and possibly in our houses. For what Nature does on a grand
scale may also be done in a small way; and principles that govern the
successful growth of plants and animals in a bottle of sea water must be
the same that govern the fauna and flora of the Pacific Ocean.
In order then to study and understand these things it will not be
entirely necessary to make a trip to the equator, to the poles, or to
travel around the world.
It has been a favorite theory with Henry D. Thoreau and John Burroughs,
those genial and poetical lovers and observers of nature, that we need
not rove all over the earth, as is the custom of many, to see this
curiosity or that, or to observe nature in her secret recesses, but that
we only have to sit down in the woods or by the sea-shore, and everything
of interest will come round to us. The little town of Concord was a whole
world in miniature to Thoreau. Everything worth finding could be found
there. And so to John Burroughs, is the juniper forest of the Hudson, a
show case, with the whole world inside. “Nature,” he says, “comes home
to one most when he is at home; the stranger and traveler finds her a
stranger and a traveler also.”
I think we may infer from this theory of our charming philosophers rather
a poetical interpretation. They would urge a careful observation and
study of phenomena in and near the places where we live, rather than
gadding up and down the earth in search of novelties. If we familiarize
ourselves with every day common objects and events of plants, animals,
and other operations in nature, we shall then always be at home when
nature calls, whether on one side or the other of the world.
I have heard of a good old lady who, when nearing the end of her earthly
existence, said she did not mind the dying if she could only breathe.
Now this goodly person had doubtless spent all the years of her life
without observing the fact that every plant or animal however small or
simple in structure must have, if nothing else, the organs for breathing,
and when that function is suspended or destroyed, life ceases. The
respiratory organs may be reduced to a single cell, wall, or membrane.
The forms of these organs, however, are exceedingly variable, elaborate,
and sometimes complicated.
In the sea, plants and animals have a compensatory relation to each
other. The plant exhales oxygen and the animal exhales carbon. That is to
say, the carbonic acid which is mixed mechanically with the water coming
in contact with the cell, wall, or membrane, covering the plant, the atom
of carbon is appropriated, freeing the two atoms of oxygen, which in turn
are appropriated by the animal.
Not only is this process of breathing compensatory and reciprocative—an
interchange of commodities—the plant giving two atoms of oxygen for one
of carbon, and the animal bringing its single but equally valuable atom
of carbon for two atoms of oxygen, but without this interchange, neither
could plant or animal live, and our world of life would become as dead as
the moon is supposed to be.
The process of breathing is so common that we seldom think about it,
unless there is an interference in some way. Each one of us sitting
quietly in this room would breathe about 1000 times in an hour, requiring
over 100 gallons of air to sustain the proper supply of oxygen for the
blood. During this time we have taken from the air a certain amount
of oxygen and have returned to it an equal amount of something else,
which we call carbon oxide, or carbonic acid gas. The oxygen has burned
the effete material which is cast out of the blood in the process of
breathing, and it is returned to the atmosphere as a kind of coal. The
fundamental principle is the same in animals that breathe water as those
that breathe air, only the apparatus is different. Animals that breathe
water have a fine capillary network of blood-vessels spread out on gills,
branchia or projections arranged so that the water shall pass rapidly
over them, and thus the carbon is carried away and the oxygen taken into
the circulation.
Animals that breathe air through lungs have little air cells, so very
small that a human lung is said to contain 600 millions of them; and
these lie in contact with the capillary circulation of the lung which
receives the oxygen and gives out the carbon. Some air-breathers have no
lungs, but merely spiracles or minute holes in the body through which the
air enters, coming in contact with the circulation.
In all cases, whatever the form, size, or character of the animal
the object is to bring the air in contact with the circulation that
oxygen may be received in exchange for the burnt material—the carbon
oxide—which, when once formed, is poisonous, and must be expelled from
the animal.
Now if we look over the earth we shall find immense deposits of coal.
Here in the United States we have nearly 200,000 square miles of coal
deposits. In other countries there is a like proportion of these carbon
deposits, such as petroleum, bitumen, and paraffine. Then there are great
forests and other vegetable growth. These have stored up the carbon
set free by the animal, and have kept the air comparatively free from
carbonic acid gas, which but for the vegetables would in a little while
have rendered our atmosphere unfit for animal use. What is true of the
air in this respect is also true of the sea.
Thus it comes about that by the process of breathing, principally, we
have the immense coal fields, the wide spread forests, and the herbage
that covers almost the entire globe. For in the air and the water
there exist the germs of animal and vegetable life so profusely, so
universally, that the proper conditions of heat and light will develop
contemporaneously, both the organic kingdoms. If we should take ten
drops of water from the middle of the Pacific Ocean, near the surface,
and add them to a small tube, say two ounces, of water that had been
deprived of life by boiling, and kept sealed for a number of years, and
place the tube in favorable conditions, we should in a few days see a
little universe spring, as it were, into existence. There might not be a
great variety of forms, but who can say that there might not be enough to
populate or re-populate some world just entering into the conditions of
such life as our earth contains, or some other world that had suffered a
reverse, or cataclysm, by which all life was destroyed.
Mr. Lloyd, Superintendent of the Birmingham Aquarium, says he kept for
eight years a bottle of sea water, well corked and covered with paper,
and that when he opened it the water was perfectly clear, free from
smell, and of the same appearance as when taken from the sea. But when
exposed for eight days to light in a window an abundance of microscopic
plants and animals began to grow, and soon covered the sides of the
bottle, and darted about in the fluid.
Having occasion some ten months ago to use some sea-water, I brought
to my house a demijohn full and placed it on the north side where the
sun seldom shines, and where it is nearly always cool; although the
temperature sometimes goes as high as 75° and 80° Fahrenheit in the
afternoons. There was no particular effort to exclude light and air; the
cork fitted loosely, and the wicker work was not unusually close. And
yet, whenever I have examined this water it is clear and free from smell,
and there are no plants or animals growing in it. But by exposure of a
small quantity to the light and warmth of a window, these have rapidly
developed. It is a fact, then, easily demonstrated in our own rooms and
houses, that by excluding light from water and keeping it in a cool place
we can arrest the growth of organisms. This is the case with springs.
The microscope fails to discover germs in spring water until it has been
exposed to the light for some time.
Acting on hints of this kind, Mr. Lloyd has constructed aquaria with two
reservoirs—one in a dark, cool place, quite large—the other in a light
and warm place, favorable to the growth of plants and animals. By means
of pipes these two reservoirs are connected so that a circulation can
be set up between the light and dark portions. A pump may be used to
force the water from the dark reservoir into the other, using vulcanite
or rubber of some kind for sea water, instead of such oxidizable metals
as brass, tin, lead, etc. The most convenient temperature is about 60°
Fahrenheit.
Thus, by exchanging the waters of these two reservoirs, as occasion
requires, we shall be able to regulate an aquarium so as to keep many
kinds of plants and animals in a healthy, growing condition.
The best aquaria are those where the water is never changed, but ever
circulated in the manner I have indicated. Water that has once been made
clear and good, and maintained plants and animals, is better than any
water newly brought from the sea. It must be remembered that evaporation
takes place from the surface of an aquarium more or less according to the
heat and dryness of the air. At a temperature of 60° in an ordinary dry
air, such as occurs some miles inland, the evaporation from a surface of
water six inches square would be about three drops in twenty-four hours.
Some very warm, dry days it would be two or three times that much. This
waste must be made up by adding occasionally some distilled water.
An aquarium must be kept free of decaying matter. If once formed the
sooner it is got rid of the better, for it will poison all creatures that
come within its influence. The larger the dark reservoir the better. It
can not be too large, but should be not less than four or five times
larger than the reservoir in which the plants and animals are kept.
Any dead matter then will quickly be burned at a low temperature—for
oxygenation by means of the dark reservoir means no more nor less than
the burning up of the effete and decaying particles thrown off by plants
and animals.
It might be profitable for me to tell now how I didn’t succeed with the
first aquarium I undertook.
It was a fine, large structure, capable of holding some twenty gallons.
The sea water was procured, and at low tide a friend went with me to
help carry an assortment of plants and animals. We had read a good deal
about the compensatory properties of these two kingdoms; how the plants
exhale oxygen and inhale carbon, and how the animals inhale oxygen and
exhale carbon, and thus preserve the equilibrium and the purity of the
water. Well, we had good luck in searching tide-pools, and the turning
over of rocks; and we returned loaded with snails, crabs, sea-anemones,
sea-urchins, clams, abelones, date fish, real fish, sea worms (with
beautiful red branchia), and sea weeds, an extensive variety of red,
green and brown, only one or two of which would grow, as I have since
learned, even in the most successful aquarium yet known. There are many
other things that I have forgotten. We had rock-work and sand, and
pebbles of beautiful colors, and a great many _iridea_, a rainbow-colored
sea weed. We intended to imitate one of the beautiful tide-pools we had
seen, and astonish our friends with a little bit of the sea, snatched up
and transported to our quiet room, away from the fog and wind and chill
of the ocean shore. We would willingly have brought the tide and some
waves, if they could have been dwarfed to the dimensions of our tank.
With these and a few other things we might have succeeded, and kept our
aquarium as long as Robert Warrington kept his in London, with unchanged
water, during a period of eighteen years.
But in eighteen hours our animals were all dead or dying; and although
the plants were in proportion—that is, we had an equilibrium—they were
almost equally in as bad a condition as the animals. First the water
began to turn cloudy. We looked at our books for light, but they were
equally obscure. Then we perceived a smell, somewhat like canned oysters,
and this smell grew till it permeated the whole house. We suspected
something wrong, so we emptied the aquarium, filtered the water, threw
away the decaying matter, and put the things in again. But the “muddy
vesture of decay” had covered the stones and entered the crevices, and
in a few hours more we had to cast the contents away. The fact is, as I
have learned since, we had a large number of bruised, broken and bleeding
organisms from the handling in transfer, that the whole ocean’s waters
could not save or heal, much less the little tank of twenty gallons.
There were no waves to carry away the dead matter, no oxygen in the water
to burn it, so it had to be breathed over and over again until the blood
was poisoned and the animal died, because it could breathe such water no
longer. And the plants began to fade and decay because their blood was
also poisoned.
Now let us turn and consider for a moment Nature’s aquarium—the sea. It
covers two-thirds of the earth’s surface, and it has been explored to
the depth of eight miles at places, without finding bottom. The average
depth, however, is about 2½ miles. All this immense mass of salt water
is inhabited with a fauna and flora in a state of nature. That is, the
hand of man has done nothing in the way of taming or cultivating them.
They are absolutely wild, whilst a large part of the earth is subject
to man’s dominion, and he was commanded to subdue it. The herbs and the
trees of the field “shall be for meat,” and his “dominion over the fish
of the sea, and over the fowl of the air,” pronounced at creation, is, as
yet, but partially accomplished. The sea and the air remain as mysteries
unsolved, and as powers unconquered. The cyclone and the tidal wave are
evidences of the untamableness of these elements. “He bindeth up the
waters in thick clouds, and the cloud is not rent under them,” was the
language of some thirty-five centuries ago, and it is equally as true and
expressive to-day.
Although the sea is inhabited at all depths, according to the best
knowledge we have at present much the largest part lies beyond daylight.
Light only penetrates a few fathoms—all below is darkness. This is the
great, deep, cool reservoir from which the upper strata is constantly
renewed by a circulation about which we, as yet, know but little. How
is this circulation kept up? Who has charge of “the doors of the sea?”
Who has “entered into the springs of the sea,” or “walked in search of
the depth?” We have some knowledge in regard to these questions. The
investigations of such men as Edward Forbes, Sir William Thompson, Dr.
Wm. B. Carpenter, Lieut. M. F. Maury, Darwin, Kane, and a host of other
scientific explorers equally as wise and industrious, have solved many
mysteries in regard to the great ocean of salt water, and that lighter
ocean of air that surrounds the earth.
Many years ago Maury wrote some striking and impressive sentences in his
“Physical Geography of Sea,” such as the following:
“Our planet is invested with two great oceans; one visible, the other
invisible; one underfoot, the other overhead; one entirely envelops it,
the other covers about two-thirds of its surface. All the water of the
one weighs about four hundred times as much as all the air of the other.”
Then again in reference to the Gulf Stream he says: “There is a river
in the ocean; in the severest droughts it never fails; in the mightiest
floods it never overflows; its banks and its bottom are of cold water,
while its current is of warm. The Gulf of Mexico is its fountain, and
its mouth is in the Arctic Seas. Its current is more rapid than the
Mississippi or the Amazon, and its volume more than a thousand times
greater. Its waters are of an indigo blue. They are so distinctly marked
that their line of junction with the common sea water may be traced by
the eye. Often one-half of the vessel may be perceived floating in Gulf
Stream water, while the other half is in common water of the sea, so
sharp is the line and such the want of affinity between those waters, and
such, too, the reluctance, so to speak, on the part of those of the Gulf
Stream to mingle with the littoral waters of the sea.”
We have all read and doubtless thought a great deal about this wonderful
stream; how England and the shores of the continent are warmed by
this water. But there are other streams equally important, if not so
distinctly marked. Every ocean and sea has its current or currents. As
the waters are warmed by the rays of the sun, they expand and flow away.
But these streams are not very deep, and the Gulf Stream is shallow
compared with the dark, cold current that moves below it, but in an
opposite direction.
[To be continued.]