257 
AMERICAN AGRICULTURIST. 
s 
Fig. 3. 
1 and 2. The Common Sticklebacks (Gasterosleus trachvrus and Leiurus) 
and their Nests. 
3. The Caddis Worm. 4. The Marsh Snail. 5. The Water Scorpion. 
the room, the plants take in the carbonic acid and send out pure 
oxygen again. (It should be stated here, that the plants only send 
out oxygen during daylight, so that while plants are healthful in 
the day time, they are not so in a room occupied at night.) 
It was the application of the above principles which led to the 
discovery of the Aquarium , or aqua-vivarium. Fishes, or other 
water animals, put into a confined portion of water, after a time, 
use up all the oxygen it contains, and replace it with poisonous 
carbonic acid, so that fresh water containing new supplies of air 
must be given to them. Sometimes all the fishes in a small pond, | 
without plants, will be killed during winter, because the ice on the j 
surface prevents the access of air. They are often seen to rush to ! 
a hole cut through the ice, in order to get a draught of fresh air. 
But put in the water such plants as will grow there, and these ! 
will use the carbonic acid produced by the fishes, and return a new 
supply of pure oxygen for them. 
In the glass vessels or aquariums shown in the illustrations, 
figures 1, 2, 3 and 4, we see fishes and plants together, and though 
the quantity of water be small, there is no need of changing it, for 
months or years, since, as above explained, the united breathing of 
the animals and plants keeps it pure. It will be seen that to have 
a healthy aquarium, the ratio of plants to animals must be such 
that their action upon the water will counterbalance each other. 
But this is not all that is necessary in an aquarium. It is found ' 
that the excrements of the animals and the decaying portions of \ 
the plants will, in a short time, render the water foul, and unfit: 
for either animals or plants. A beautiful discovery counteracts 
this difficulty. We find that water snails of several kinds, as well 
as various other small animals, actually feed upon these decaying 
substances. These snails, thus formed from decaying matter, in 
turn become pure food for the fishes themselves. Did it ever oc¬ 
cur to you, reader, that the snails in the bottoms of rivers, lakes 
and oceans are litterally scavengers, whose office seems to be to 
“ clean up ” the habitations of other animals, and purify the water 
in which they live. Yet such is the case, and the more we study 
the Creator’s works, the more we shall be impressed with the fact 
that He has made nothing in vain. 
So, then, a perfect aquarium is ope which, like the natural reser¬ 
voirs of water, contains animals to breathe oxygen, and form car¬ 
bonic acid, plants to absorb the carbonic acid and restore pure oxy 
gen, and snails or other small animals to consume the decaying 
materials of both large animals and plants, and thus keep the wa¬ 
ter pure. 
EXPLANATION OF THE PLATES. 
Aquariums are made of various forms and sizes. Figures 1 and 
2 illustrate two of the simplest. Figure 1 is a box with glass 
sides. It may be but a foot or two in length, width and hight, or 
it may be several feet long and wide. An English gentleman, Mr. 
Gosse, who has made many improvements upon the first discov¬ 
eries of Mr. Warrington, actually kept over one hundred living 
specimens in a box like this, only two feet long and one- 
and-a-half feet wide. He, however, found his vessel too small, 
and the number of animals was decreased. Those of this shape, 
now made for sale by dealers in England, are usually formed with 
slate floors and backs, and zinc columns and mountings. Care 
must be taken that putty, cement or paint be not so used as to in¬ 
jure the water. The smallest and most simple are about 15 inches 
long, and 10 inches broad. These may be set upon a mantel, a 
shelf, or on a small table as here represented. A bed of pebbles 
and sand, about three inches deep, is placed upon the floor. Pieces 
of rock are variously arranged to give variety and a pleasing effect 
upon the eye. A point or two of the rock-work may well project 
above the water. Various kinds of water-growing plants are set 
in the sand, such as watei-lilies, water-plantains, water-iris, airow- 
head, water-cress, rnarestail, duck-weed, &c. There are, as yet, 
v°ry few aquariums in this country, except a fine collection just 
introduced into the American Museum in this city. These are a 
pleasing sight, well worthy a day’s visit. We have spent many 
piofitable hours in studying these caged inhabitants of the deep, 
disporting in their own element, and exhibiting all thenatuial phe¬ 
nomena of active life. We are glad to learn that the proprietors, 
Messrs. Greenwood & Butler, are preparing to furnish the glass 
vessels, ready stocked, when desired, and at reasonable prices, i 
I No. 2 is a common bell-glass, of the simpliest, cheapest kind, 
| mounted upon ;i turned wooden stand. On the top ot the two 
Fig. 4. 
1 $2. Minnow?. 8, Ths Perch. 4. TheTench. r,. The Eoacil 
