b 34 
AMERICAN AGRICULTURIST. 
[November, 
The Doctors Talks. 
Freddie S. and Harry W. are neighbors in New 
Jersey, and are much interested in turtles, frogs and 
other animals, of the vicinity. They wish to make 
an aquarium for animals that live in water, and ask 
for the best size, and if the frame can be wood. 
AN AQUARIUM TANK. 
The frame of this is sometimes of wood, but 
this is often troublesome, and an iron one, though 
more expensive at first, is much better. But I advise 
not to get a square or regular tank, at least not at 
first, but to use a glass jar. Much about managing 
an aquarium can only be learned by practice, and 
the jar answers for this, while the animals will be 
quite as well off as in a more elegant home. 
WHAT IS AN AQUARIUM ? 
A vessel of water holding fish, tadpoles, etc., in 
which water must be changed every day or two, is 
not a proper aquarium. Fishes and other creatures 
iive for years in a pond, or deep pool, but in such 
an artificial pond, the water must be changed or 
they will die. To imitate nature we need plants, 
aS well as animals in our artificial pond. In real 
ADD ANIMAL LIFE SLOW’LT. 
Begin with snails from ponds and ditches, and a 
few tadpoles—funny fellows they are—and when 
all has gone well for some days you may add a very 
small fish or two. Frogs and turtles breathe the 
air, and you must so arrange that they can leave 
the water. The engraving of a Frenchman’s aqua¬ 
rium for frogs, shows how he provided a ladder 
and branch of a tree—willow will answer—to give 
them exercise, and all is covered with a net to pre¬ 
vent escape. 
PLANTS AND AMIMALS. 
These are necessary to one another in the aqua¬ 
rium. Perhaps Freddie and Harry are not old 
enough to understand the whole story, 
but they know that fishes, tadpoles, and 
some snails can live entirely under water. 
They breathe the water, or more properly 
the air, dissolved in the water. When 
these are confined in ajar of water, after 
they have taken out all the air it contain¬ 
ed—breathed it out—they will become un¬ 
easy, go to the surface and try to breathe 
the air and if not given fresh water will 
soon die. Of the air dissolved in the wa¬ 
ter only a small part of it is life 
supporting. This is Oxygen , not 
a hard word for my young 
friends to learn, especially as 
their lives depend upon having 
a constant abundance of it. 
Oxygen is that part of the air 
which keeps Freddie and Harry 
alive, and sustains the lives of 
all other animals. Inbreathing 
air we use up the oxygen, and 
we return to the air a deadly 
poisonous gas, carbonic acid. A 
man or other animal shut up in 
a close, tight box, or small 
room, would soon die ; the oxy¬ 
gen would be used up-and 
the gas breathed out would 
soon cause death. Animals that 
live in the water breathe more 
slowly, but in time, they take 
all the free oxygen out, giving 
back this very poisonous gas. 
WHAT ABOUT THE PLANTS? 
Plants growing in the water give out 
to it oxygen, just what the fishes, etc., 
need, so if we have enough plants and 
not too much animal life in the water, 
our artificial pond, or aquarium, will 
keep on for years, without need of 
changing the water. Where do plants 
get their oxygen ?—a very proper ques¬ 
tion. The carbonic acid the fishes, etc., 
give out in breathing, is just what the 
plants need. This is in part oxygen, so 
united with something else as to make a 
deadly poison to animals, while it is just 
the life of the plants. These take it in 
through their leaves, split it up, or take 
it apart, so to speak, and send the good 
oxygen back into the water to keep the fishes, 
and all other animals alive. 
JUST LOOK AT THE ARRANGEMENT. 
We have plants and animals, fishes, etc., in our 
jar, both in water. The animals are all the time 
taking oxygen out of the water, and giving back to 
it a deadly-poison (carbonic acid). The plants take 
up this poison, which would otherwise kill the ani¬ 
mals, and in return give out the life-sustaining oxy¬ 
gen to support them. Can anything be more beau¬ 
tiful ? Tour little jar, which should now be all the 
more interesting to you, shows in a small way the 
round of life in the ponds and other bodies of 
water. 
A PRACTICAL POINT HERE. 
In managing your jar, do not have too many ani¬ 
mals, fishes, snails, etc., for your plants. This can 
only be learned by experience, but if the plant life 
and animal life are in the right proportions, the 
plants and animals will give to each other what 
they need year after year. The Doctor. 
A Clever Chinese Toy. 
The Chinese make many toys, but none are 
more amusing than that shown in figure 1. No 
doubt the Chinese have a name for it, but not 
knowing what it is, we will call it “ The Acro¬ 
bats.” The box in which the toy is packed is so 
arranged as to form several steps when it is pulled 
out. The acrobats are two, and apparently have 
hold of two long poles between which they stand. 
Unlike the Chinese women, these men have enor¬ 
mously large feet; they need these to keep them 
steady in their performance. To make them per¬ 
form, the steps are arranged, and the two figures 
Fig. 1.— THE CHINESE ACROBATS. 
with their poles are placed at the top. The rear 
acrobat goes up, turns a summerset between the 
poles and lands on the step below ; the other then 
repeats the same performance, and over they go, 
one after another, until the bottom is reached. By 
building up other steps of the same size the tumb¬ 
ling may be greatly prolonged. “ How is it done?” 
you will ask. This is shown in figure 2, where you 
will see that the poles used by the acrobats arc hol¬ 
low. In each of the holes is placed a little quick¬ 
silver or mercury (6), which you no doubt know 
is a heavy liquid metal which runs as readily as 
water. When the mercury runs down towards the 
Fig. 2.—HOW THE ACROBATS ARE MADE. 
figure 8, its weight lifts the other (A), and he lands 
on the step below ; this brings the poles in a slant¬ 
ing position again, the mercury runs to their lower 
ends and by its weight, sends over the rear figure 
in the same manner, and so on until both are on 
the same level. At first sight this life-like motion 
of the big-footed figures is very puzzling, but 
it is very simple when you know how it is done. 
ponds, slow running streams and ditches, there is 
an abundance of plant-life—not the large plants 
growing on the margins with their roots only in 
the water, but if you look closely you will find a 
great number of plants, some of which grow en¬ 
tirely under the water, and others with their 
greater portion below the surface with a few leaves 
floating above. 1 f we place such plants in our arti¬ 
ficial pond, all will go well and we need not change 
the water to keep our fish, etc., alive. 
PROCURE A GLASS JAR. 
The larger the better, though a two-quart one 
will afford much amusement. Place in the bottom 
an inch or so of clean pebbles, or coarse washed 
sand, that from the river-side is best, and fill up 
With river or brook water, or if neither of these 
i3 at hand, use rain-water. Now get some of 
the plants that grow wholly under water, wash 
them, tie small stones to the lower ends to sink 
them, and place them in the jar; let all stand for a 
few days, or until the water is perfectly clear. 
