THE YOUNG SCIENTIST. 
55 
we must have the light reflected from 
below the plate. 
With the camera above illustrated and 
described, and a number of prepared 
plates, any one, with a little practice, can 
fill a day or a week at home or abroad, 
with profitable pleasure. 
There are only two drawbacks to this 
practice : The first is the lack of artistic 
freedom. All you can do is to copy what 
is thrown on your plate ; this can be over- 
come by an artist, but should not be at- 
tempted by any one else. The second 
disadvantage is in being unable in many 
instances to find a good standing place 
for the tripod, so as to get just the view 
you wish; but the great advantage of 
being able to etch your plate on the spot 
where a suitable place can be obtained, 
knowing that it is absolutely true to na- 
ture, will, in most minds, more than com- 
pensate far the disadvantages spoken of. 
Let me, in closing, recommend the 
making of simple outlines first. A well- 
drawn outline is far better than a poorly- 
shaded picture, and can express a great 
deal more than is often imagined. After 
some practice in shading with a pencil, 
you can easily add it on your plates. 
they emit a decidedly strong, unpleasant, 
and pungent odor, but, when skinned and 
cooked, the odor disappears, and they are 
quite palatable. This is not so bad, how- 
ever, as sending toads legs to the New 
York market, mixed up with a few frogs 
legs, and yet I have seen the remains of 
thousands of toads that had been slaugh- 
tered for this purpose. 
Frogs for the Aquarium. 
BY A. W. ROBERTS. 
NEXT to the young of the bull frog, the 
most desirable variety of the frog 
family for aquaria is the leopard frog. 
Fig. 1, which is generally acknowledged 
to be the handsomest of all our native 
frogs. In habit he is less aquatic than 
the bull-frog, often being found long dis- 
tances from water ; but in the spring of 
the year, during the breeding season, it 
remains near the water. The tadpoles of 
this frog cannot be distinguished from 
those of other frogs, and are, undoubtedly, 
more scarce; out of all the tadpoles of 
various kinds of frogs that I have raised, 
I never obtained a leopard frog, and from 
this I judge it is much less prolific than 
other varieties. I have known of large 
quantities of these frogs being taken in 
the winter time, in spring holes, for the 
New York Market. They are then in a 
semi-dormant condition, in which state 
Fig. 1.— THE LEOPAED FEOG. 
The smallest of all frogs is the tiny tree 
frog, or Pickering's Hy lodes. Fig. 2. This 
beautiful little reptile ought to be in the 
possession of every owner of an aquarium. 
A dozen to one tank of medium size is 
none too many. To keep these frogs in 
good condition in the aquarium, the sur- 
face of the water must be partially cov- 
ered with bladderwort or duckweed, so as 
THE TEEE FEOG. 
to afford them a resting place. The top 
of the tank must be provided with a close- 
fitting frame, on which is stretched fine 
netting, to prevent their escape. During 
the spawning season the voice of this frog 
is constantly heard along the margins of 
ponds, and consists of a shrill piping 
note. This piping they continue more or 
less through the summer season. In color 
they are changeable ; and, as a rule, take 
on the colors of surrounding objects. 
When sick, or under the influence of 
