THE YOUNG SCIENTIST. 
143 
Improved Carmine Ink. 
The solubility of carmine lake in caustic aqua 
ammonia is attended with this disadvantage; 
that in consequence of the alkaline properties 
of ammonia, the cochineal pigment will, in 
time, form a basic compound, which in contact 
with a steel pen no longer produces the intense 
red, but rather a blackish color. To avoid this 
evil, prepare the ink as follows : Saturate 1 
gramme of pure carmine with 15 grammes of 
acetate of ammonia solution and an equal quan- 
tity of distilled water, in a porcelain mortar, and 
allow" the whole to stand for some time. In this 
way a portion of the alumina which is combined 
with the carmine dye, is taken up by the acetic 
acid of the ammonia salt, and separates as pre- 
cipitate, while the pure pigment of the cochineal 
remains dissolved in the half saturated am- 
monia. It is now filtered, and a few drops 
of pure white syrup added to thicken it. In this 
way an excellent red drawing ink is obtained, 
which holds its color for a long time. A solu- 
tion of gum arable cannot be employed to 
thicken this ink, as it still contains some acetic 
acid, which would coagulate the bassorine, 
which is one of the natural constituents of gum 
arahic.— English Mechanic. 
Red Oak as an Ornamental Wood.— Red 
oak is found in abundance in almost all parts of 
the country, and from its plentifulness and its 
unsuitableness for a large majority of the com- 
mercial uses to which white oak is utilized, has 
been looked upon with a contempt, but little 
deserved when its adaptability to the manufac- 
' ture of furniture is taken into consideration. It 
is more brittle than white oak and more porous, 
and this has probably been the cause of its 
neglect for shipbuilding purposes, combined 
with the fact that it is more susceptible to the 
attacks of the marine insects which abound in salt 
water. It is not a wood which will stand the 
variations of wet and dry ; and while white oak 
was to be had in abundance, the red oak was 
thought fit only to be made into flour barrels. 
When sawed bastard, so as to fully develop the 
grain, there is no question of its beauty being 
equal to black walnut, in the eyes of those who 
are not prejudiced in favor of the rich dark color 
of the latter. 
Fine Linen.— A(?cording to the Building News, 
a piece of Hnen has been found at Memphis con- 
taining 540 picks to the inch, and it is recorded 
that one of the Pharaohs sent to the Lydian king, 
Croesus, a corselet made of linen and wrought 
with gold, each fine thread of which was com- 
posed of 360 smaller threads twisted together! 
The ancient Egyptians wove a linen called the 
"linen of justice," or "justification." So beau- 
tiful and valuable was it that it was esteemed the 
most acceptable offering to the "Restorer of 
Life." A few hand looms can be seen at work in 
the Eastern bazaars of Cairo, the cloth woven in 
which rivals in texture, color and design the 
finest glass screens of Munich. 
Improved Varnish for Special Purposes.— 
Moreau, of Paris, patents the following improved 
varnish: Infuse 195 grammes of gum sandarach 
in one-fourth litre spirits of wine ; also 120 
grammes spirits of turpentine in three-fourths 
litre spirits of wine. Stand the two infusions in 
a water batli for half an hour; then mix. and 
place the mixture in the water bath for fourteen 
minutes more. Allow it to stand for twenty-four 
hours, and filter through cotton. The result is a 
colorless varnish, which may be given any de- 
sired tint with saffron, Prussian blue, indigo, .etc. 
The i^atentee states that the effects resemble 
those formerly produced by the famous "Vernis 
Martin," the secret of wdiich is now lost. 
A New Cake Tryer.— A broom splint has oc- 
cupied a prominent position among aids to cook- 
ing for an indefinite period of time, and house- 
keepers who are immaculate in all other matters 
often take a splint from a broom with which they 
have perhaps swept the kitchen, and "try" a 
delicate cake with it. A much better way is to 
buy a cheap little "brush broom," and keep it 
for this and no otlier purpose ; one will last a life- 
time ; hang it in tlie dining-room near the 
kitchen door. If so disposed you can make a 
pretty case for it of fancy paper or Turkish 
towelling, then one will not be tempted to use it 
for anything else in the kitchen. 
Fine Drilling-.— Professor Edward C. Piclcer- 
ing, of Harvard College, says that in undertaking 
to measure the intensity of the light of the satel- 
lites of Mars, he had occasion to need an ex- 
tremely small hole. Among the artisans who es- 
sayed to furnish what was required was one who 
had succeeded in making a hole edgewise through 
an old fashioned three cent piece, and another 
who had pierced a needle through from end to 
end. A hole about the twenty-five hundredth 
part of an inch in diameter was finally secured. 
Cheap Pencil-mark Eraser.— Caoutchouc is 
dissolved in carbon disulphide, the solution is 
intimately mixed with enough starch flour to 
form a dough, and exposing the mass, in suitable 
pieces, to the air, until all odor of carbon disul- 
phide has disappeared. The product is an excel- 
lent eraser for lead pencil marks from paper. If, 
in addition to stareli flour, finely powdered 
pumice stone be added to the mass, it will be 
suitable for erasing ink marks or writing from 
paper.- -iVw7 Bernedies. 
Blue Ink.— Take Berlin blue, 6 parts; oxalic 
acid, 1 pait. Mix thoroughly into a soft paste 
with water. Dissolve in rain water, and add a 
little gum arable. 
