HUNTING VEGETABLES AND PLANTS
One night, while engaged in the usual evening discussion, many topics
were mentioned, things connected with the day's adventures talked over,
and plans for the following day considered.
As usual, George was the persistent questioner, but Harry was the one to
utilize the meaning, and generally the first to take advantage in a
practical way of the information thus obtained.
We have stated heretofore that George was the theorist and Harry the
practical one. George delighted to delve down into mysteries; but Harry
utilized the knowledge in constructing and building articles. Both,
therefore, had useful accomplishments. To learn and to do are the great
things in life.
During the day the boys had turned out a nice sample of bread, and
George, as usual, began the questioning:
"Professor, you said the other day, that fermentation caused a change in
the dough, and that it was due to heat. I am curious to know why heat
should cause it to ferment?"
"Heat develops bacteria, a tiny germ, which grows so rapidly in a short
time, that millions are produced. These living organisms cause gases to
form, and they continue to breed and grow and multiply so long as they
have anything to feed on."
"And we eat all that stuff and call it good?"
"Yes; and why not? Every part of your body contains the little
creatures, and they really keep you alive, and preserve your health, as
well as prevent diseases."
"Why so?"
"Most germs are of the harmless type, and it is because of the vast
numbers of the harmless ones that the few poisonous or disease germs are
killed. Water has millions of them in every cubic inch. Professor Dewar,
a great English chemist, calls them nature's policemen. If a typhoid
fever germ, for example, should be introduced among so many germs, as is
the case every day, a fight at once takes place, and where a person is
finally attacked with the fever, it is because the germs escaped the
policemen who were on duty."
"That sounds like a romance."
"Yes; the life history of those germs is really a wonderful thing, and
books have been written about them. They exist in tribes, as it were;
some of them can live only where oxygen is present, and some live on
nitrogen only; others on carbon. But that is not all. Man has learned to
use them, so they will work just as surely as our yaks work for us under
our direction."
"How interesting! In what way do we use them?"
"In what is called the septic system of treating sewage. You know that
sewage from the kitchen contains all kinds of meat and vegetables, and
the more it has fermented the stronger becomes the odor and the greater
are the number of bacteria in the sewage. The sewage in the liquid state
is first placed in a reservoir, and at a certain temperature the germs
grow very rapidly, and, of course, eat up the vegetable and animal
matter until it is nearly all consumed. Then it is run off into another
reservoir which has another tribe of germs in it, those that live on
carbon, and which are not harmful to man, and when these two tribes meet
war is declared, and they fight to the death. The harmless germs are
victorious in every battle, and when the sewage is discharged into a
stream, or used for irrigating purposes, few, if any, of the harmful
germs remain."
"So in using germs the object is to cultivate one kind to kill another
kind?"
"Not always; chemists have found out that man and animals absorb oxygen
and expel nitrogen, in order to live; and that plants take in and live
on nitrogen, and give out oxygen. They further learned that certain
germs make nitrogen, just the same as we found that certain germs made
carbonic gas in the dough; so that the United States Department of
Agriculture, through its chemical division, concluded to set the germs
to work, and the department will now send a box containing millions of
the tiny creatures to any farmer who applies for them."
"When they get them, how do they set them to work?"
"The germs are thrown into a tub of water, and the seed, like corn, is
put into the water and allowed to remain for a certain length of time.
When the seed is taken out, more or less of the germs remains on each
kernel, and when it is put into the ground the germs keep on working,
making nitrogen which the growing plant absorbs. It is wonderful to see
the effect in a field where one row has these germ-infected seeds, and
the other rows are not so treated."
It was now May, and the weather was slightly cooler, but there was
neither snow nor frost. North of the equator it was growing warmer,
because the winter had passed. Here the summer had gone, and winter was
coming on. From every indication they were not in a cold climate.
"Why do you think we shall not have any snow?" was Harry's inquiry.
"I notice too many trees, as well as shrubs and flowers, which could not
live if we had frosts or freezing weather. Many of the trees about here
do not shed their leaves, and the kind of animals which we now know
exist here are sufficient evidence that we need not fear cold weather."
For more than a week the boys and the Professor put in their time
prospecting in the hills and in carting various ores and mineralogical
samples to their workshop.
The pelts which were on hand needed curing and besides there were also
four yak pelts which had to be tanned, as shoe leather was badly needed.
The hide originally dehaired was long ago ready for tanning, as well as
the later ones.
"What shall we use for the tanning process?"
"The bark of certain trees must be procured, so if you can find either
oak, hemlock, birch or beech trees, we can probably make a tanning
compound which will serve our purpose."
"In what way will the bark of those trees tan the leather?"
"All the barks named contain what is called tannic acid. Other elements
also are used, such as gallic acid, alum, sulphate of iron, and copper,
salt, and other agents."
"What are the chemicals for?"
[Illustration: _Fig. 13. Tanning Vat._]
"The tannic acid or the chemicals act on the skins, or, rather on the
gelatin, glutin and albumen in the skins, and thus harden the texture
and preserve it. Where tannin is not used and only the chemicals are
employed, it is called 'tawing' the leather, instead of 'tanning.'"
"Well, we can get the bark; I know where there are several oak trees,
and also a number of beech trees."
"Then gather the bark by all means, and by the way, if you can find gall
nuts we could use them to advantage."
"We don't know what they are."
"Then, if you can get some sumac, we can use that."
"Yes, I know; the kind with the long, red leaves."
"That is what I mean."
"Do the gall nuts have tannic acid?"
"Yes; but principally gallic acid, but gallic acid will also tan the
skins so as to make leather. The principal use of the gall nut is for
making ink."
"What kind of tree does the gall nut grow on?"
"On any kind of tree or bush."
"That is rather odd."
"It is not the fruit of any tree, but is produced by the gall fly, which
punctures almost any kind of tree or shrub. In this puncture the insect
lays its eggs, and the tree in trying to treat the wound covers up the
egg, and the sap, flowing from the tree, forms a sort of nut which
finally hardens and produces a most bitter substance deposited by the
fly. The nut is about the size of a marble, and must be gathered before
the larva is hatched out. It is the most valuable nut in the world."
The necessary bark for the tanning process was ready within the next two
days, and a tank prepared in which the hides were laid spread out, with
the bark between them and covered with water.
"In our conversations, Professor, you have the habit in describing
plants, and especially the leaves to call them by certain names. It
would help us if we knew just what you meant by the different names you
give them."
"That is a wise suggestion, because it has been said that the basis of
knowledge, or of true science, is correct definitions.[1] What is meant
by that is this: We should both have an understanding of the term used
to describe a thing. In our talks I have tried to avoid the use of what
is called technical terms, but it is difficult to describe some things
without using such terms, and I have for some time thought of making a
list of the things we are talking about, and defining them, so you can
at any time go there and look up the definition."
[Footnote 1: Each of these books has the Professor's definitions on the
last pages.]
[Illustration: _Fig. 14. Serrate. Fig. 15. Bi-serrate._]
"If you would make drawings of the different kinds of leaves and give
their names we could hang them up and could look at them any time."
"The leaf is the proper part to commence on, because it is the most
important thing of every plant, or tree, or shrub."
"What, more important than the fruit or the flower, or the nut that
grows on the tree?"
"That is just what I mean. When you smell the rich red flower of the
rose, or look at the pure white petals of the lily, or the
sweet-smelling blossoms of the orange or the jasmine, you are simply
seeing or smelling leaves. The fruit itself, whether in the form of an
apple, or a berry or a nut, is simply a form of leaf, a perfected form
of the plant, or bush, or tree. Originally all these fruits, flowers and
nuts were but leaves in an undeveloped state."
"I never heard of such a thing before."
"It is a subject treated of in botanical knowledge which is called
Morphology, and the object is to show that every fruit and flower was
developed, in accordance with a well-known law, from the particular
shape or form of the leaf. We can go into that branch of the subject
later on. What we now want is to know something about the shape of the
leaf, so we can have a starting point. There are two particular things
about leaves; one has reference to the shape of the leaf, and the other
to the way in which the edges are formed. To simplify the explanation,
the drawings which I make pertain only to the edges. That will be
sufficient for one time.
"Look at Fig. 14. The edges are like the teeth of a saw. This is called
the serrate leaf. The rose and the common nettle have such leaves.
"Fig. 15 shows a leaf with a saw tooth edge wherein the teeth themselves
have a lot of little saw teeth, as in the nettle-leaved bell-flower, and
this is called bi-serrate.
"Fig. 16 has very large, sharp teeth, not pointing in any particular
direction, like the oak leaf. This is called the dentate, or tooth.
"Fig. 17 has rounded projections instead of angular teeth, and is called
crenate. Ground ivy and horseradish have such leaves.
"When we make drawings of the shapes of the leaves that will take us
along another step, and thus enable us to find out just what kind of
tree or plant we are talking about."
[Illustration: _Fig. 16. Dentate. Fig. 17. Crenate._]
The following day Harry proposed a trip over to the cave which George
had discovered at the time he found the big air pocket that shot water
and spray out into the ocean.
"I am interested," he said, "in seeing the air pocket George spoke
about, and we might as well take our vacation to-day."
"As the distance is not great we need not bother about taking our
luncheon along." And off they started, with the Professor bringing up
the rear.
The course was first to Observation Hill, where they had erected a new
and a larger pole than the one which had so mysteriously disappeared two
months before. On every such visit it was the duty of the one who made
the trip to scan the horizon in every direction.
It must not be inferred that because the boys were engaged in work which
was all-absorbing that they had no thoughts of home, and had given up
all hopes of a final rescue. If they could only let the people at home
know they were alive and happy--that is, in learning the secrets of
nature and in the exciting exploring trips, they would be satisfied.
They had no time to think of these things when they were at work, but in
the night their thoughts often wandered back again to their homes and
friends. Could they be blamed for that homesick feeling which came over
them?
"Now lead the way, George; we want to see some more of your mysteries.
Isn't it fortunate that the tide is out? It will give us a good chance
to investigate."
The path which George had taken was farther to the right, but as he was
in a hurry to get down as quickly as possible he followed a course,
which was much steeper, with Harry and the Professor close on his heels.
When the bottom was reached there was no sign of a pocket, or a cave, or
anything of that kind. George was very much annoyed. He could not be
mistaken in the position, as it was directly to the right of Observation
Hill, and not three hundred feet from the spot where Harry had landed on
his first trip to the island.
"It seems to me, George, we are too low down. At high tide this place is
all covered with water. It must he higher up in the cliff sides."
Harry scrambled up again part way, and shortly afterwards cried out: "I
have found something here; come up at once."
He was distant not more than twenty feet above them, but so rugged were
the cliffs that the opening was entirely hidden from below.
[Illustration: _Fig. 18. Cave Entrance._]
"This is an example of the corrosive effects of the sea, and of the
elements in the water and in the rock. As these rocks are limestone
formations, we may be able to see some beautiful decorations within, if
the cave is of any extent."
"It is awful dark in there. I wish we hadn't forgotten the candles," he
said, as he glanced at the Professor, who seemed to be quite absorbed in
examining the rocks.
"Don't you think we had better go in?"
"I should like to do so, but we haven't any candles."
"I thought you came here for the purpose of examining the cave?"
"So we did."
"And came without making any preparations for it?" As he said this he
drew out one of the small candles which they had been making and using
for their evening work and recreation.
George and Harry were both very much ashamed of their carelessness. The
Professor, on the other hand, did not make another remark on the
subject. No doubt the silent rebuke was a lesson they would retain much
better than if it should be more forcibly presented.
The boys, be it said to their credit, never resented any word or action
on the part of the Professor. They had only love and veneration for him;
and the Professor, by his constant attitude toward them, showed that
even these careless actions or any other examples of thoughtlessness on
the part of the boys, were part of the training that would teach lessons
of value.
Below the mouth of the cave were little streams of water which looked
like springs, and the Professor was of the opinion that the floor or
interior of the cave must be lower than the entrance.
"Why do you think so?" was the inquiry.
"The springs below seem to indicate that when the high tide fills the
cave, the bottom of the cave leaks enough to let out the water. The
height of the mouth from the normal level of the water is much above the
usual high tide level of the water, and it is only when there is an
abnormally high tide, as on the day that George saw it, when the cave
could be filled with water."
"Who will go in first?" said George. "I have no objection to taking the
lead; so here goes."
George moved forward cautiously, holding the candle, and Harry followed
with another. The opening was fully ten feet high, and at least that
much in width, but irregularly formed. They went in straight for twenty
feet or more, when George announced that he had reached a wall. The
Professor, who was in the rear, called out: "Look to the right, there is
a turn here."
Such was the case, but the broken up character of the sides and floor
prevented them from readily grasping the formation. After making a jog
the cave again turned into the cliff, practically on a line with the
opening section or mouth of the cave. It was dark at first, but now, for
some peculiar reason, it grew lighter as they advanced, and finally
George stopped.
"What makes that peculiar light?"
"It is not a light; it is merely white walls and ceilings."
"What causes it?"
"Carbonate of lime, or chalk, which is caused by lime water coming from
above and trickling down through to openings or crevices, and leaving
the deposits there. It is not an uncommon thing in caves, and I
foreshadowed it in the cave when I stated that the rocks were of
limestone formation. You will remember we made lime from this kind of
rock."
A loud splash and a groan-like noise put further conversation at an end.
"What was that?" asked George, as he retreated. In doing so he tripped,
and, in falling, the light he carried was extinguished as it flew from
his hand.
Clearly there was water ahead. "Let us go forward, a little closer,"
said the Professor. "You might get your guns ready, in case of
necessity."
Within thirty feet of them was the edge of water, and the light threw a
beam beyond for a hundred feet or more.
"It seems as though we have reached the end of our explorations here."
As they looked, the water was agitated, and it was plain that some
aquatic animal was within the cave.
To return was the only thing to do, and as they went back the sides of
the cavern were examined, and the Professor took a number of samples, as
he said: "Don't lose the candle until we get where we can see daylight.
Although we are not more than two hundred feet from the mouth of the
cave, the remarkable bend or jog near the mouth of the cave makes it as
dark as though we were in a thousand feet."
"What sort of animal do you suppose that was?"
"Possibly a sea lion, or a seal."
After the open air was reached the Professor said: "I do not see how
this cave would account for the phenomena that George saw the other
day."
"Why not?"
"The cave is too deep. It is not a true air pocket, and----"
"What is this? Here is another one, still larger, and lower down. Here,
hold the candle." Harry was down in an instant.
"Probably this is what George saw."
True enough; it was an air pocket which extended in about fifty feet,
and had no passageway beyond.