THE YOUNG SCIENTIST. 
15 
Feeding" Terrapins. 
The Washington Globe tells us that in one of 
the fish-ponds of the Smithsonian Institution at 
Washington, some twenty varieties of terrapin 
have been kept for purely scientific purposes. 
It was the custom to feed them on such in- 
terloping- fish as disturbed the fish-cultural 
economy of other preserves. A low goldfish, a 
hybrid trout, a carp of impure race, would be 
thrown to the terrapins. Sometimes these fish 
were eaten, but mostly were haughtily dis- 
dained. One day this Spring, a gardener who 
had been cutting the blooming clover, filled his 
barrow with the fragrant load and trundled it 
over a plank. He made a misstep and dumped 
his clover into the terrapin pond. In an instant 
the water was in a commotion. Every terrapin, 
no matter whether from Long Island Sound or 
the Gulf of Mexico, was seen busy devouring 
the clover. Like Ella's roast pig, the secret of 
feeding terrapins was discovered. Learned and 
grave Smithsonian professors chuckled over it. 
During the past Summer the daily allowance 
for the Smithsonian terrapins has been a bar- 
row-load of sweet clover. This hint may be of 
service to those who keep these animals as pets 
in aquaria or elsewhere. 
Shop Counters may be cleaned by the use of 
the following mixture, which must be sparingly 
applied by means of a rubber of cotton: Linseed 
oil, 1 pint ; alcohol, 4 ounces ; acetic acid, 4 ounces ; 
spirits turpentine, 4 ounces ; muriate of antimony, 
1 ounce. 
Mucilage for Mineralogrical Specimens.— 
This cement is described as invaluable for mend- 
ing fossils and minerals, and for attaching 
labels to them, being very adhesive and never 
becoming brittle or scaling off. Starch, two parts ; 
white sugar, eight ; gum arable, sixteen parts ; 
water, sufficient. Dissolve the gum, add the 
sugar and starch, and boil until the starch be- 
comes transparent. 
Cement for Broken Delf or China.— The 
following cement dries rapidly, .so that in two or 
three days the mended articles are quite firm, 
while with oil or varnish cements (such as white 
lead) weeks are required. Make a thick solution 
of gum arable in water, then stir in plaster-of- 
Paris until the mixture becomes a sticky paste. 
Apply with a brush to the broken edges, and stick | 
them together. j 
To Save Articles from Rats— Eats are ac- I 
complished rope-walkers, and are able to make 1 
their way even along very small cords. Conse- } 
quently, so long as they can mount upon the j 
lines, nothing edible suspended therefrom is 
safe from their attacks. Perfect security may be 
attained by using wires, upon which circular 
pieces of tin are strung, the meat, grain etc., 
being hung between the tin pieces. The rats can- 
i not pass the tin circles, because, as they attempt 
to climb over them after walking out on the wire, 
J the pieces revolve. 
Painting- Gilt Paper.— We wished to paint, 
j with water colors, a monogram on gilt paper, but 
I could not get the paint to lie, not even when 
mixed with gum; it either scaled off, or was 
patchy. After trying various expedients, we 
'scratched all over the surface of the monogram 
I with a hard lead pencil, and we then found that 
! the water colors could be easily painted on the 
surface. Their effect on the gold ground Avas 
very great, and perhaps some of our " illumina- 
ting" readers may thank us for illuminating 
them with this ' wrinkle."— Prm/6>?'s' Register. 
Lamps With Colored Flames.— It is said 
that glycerine may be burned in any lamp so long 
i as the flame is kept on a level with the liquid, 
j The latter, on account of its viscidity, will not 
j ascend an elevated wick. As the flame, like that 
I of alcohol, is almost colorless, and as the material 
I is especially adapted for dissolving a large pro- 
portion of saline substances, M. Schering has re- 
cently made experiments in coloring the flame 
with various bodies, and with satisfactory results. 
By introducing substances rich in carbon, it ap- 
pears that the flame may be rendered suitable for 
illuminating purposes. 
Hot Sand as a Bed-Warmer,— The good 
effect of hot water or a hot brick when placed in 
bed with persons who are weak or sickly, is well 
known. A bottle of hot water is a general fa- 
vorite, but something quite as good, and a great 
deal more pleasant, is a bag of hot sand. Get 
some clean, fine sand, dry it thoroughly in a 
kettle on the stove, make a bag about eight inches 
square of flannel, flll it with the dry sand, sew the 
opening carefully together, and cover the bag 
with cotton or linen cloth. This will prevent the 
sand from sifting out, and will also enable you to 
heat the bag quickly by placing it in the oven, or 
on the top of the stove. After once using this you 
will never again attempt to warm the feet or 
hands of a sick person with a bottle of hot water 
or a brick. The sand holds the heat a long time, 
and the bag can be tucked up to the back without 
hurting the invalid. It is a good plan to make 
two or three of the bags and keep them ready for 
use. 
To Write Permanently on Glass.— The sur- 
face of the glass is gently heated over an alcohol 
lamp, or Bunsen gas-flame, until the vapor of 
water ceases to condense upon it, when it is to be 
coated with a varnish made by dissolving 8 
grammes of sandarac and 4 grammes of mastic in 
80 grammes of alcohol (95 percent.) The solution 
is easily effected by heating the ingredients in a 
flask. It forms a varnish which is very hard, and 
ought to be completely transparent; if the surface 
over which it is poured is cold, it becomes opaque. 
