HOW TO CLEAN DIATOMS.--As a general rule, we may say that every
specimen of diatomaceous earth or rock needs a special treatment. The
following, however, may serve as a basic treatment, from which such
departure may be taken in each case as the nature of the specimen
would indicate: Boil the material in hydrochloric acid, in a test
tube, from two to five minutes. Let settle, pour off the hydrochloric
acid, substitute nitric acid in its place, and boil again for two or
three minutes. Pour into a beaker of water, stir a moment with a glass
rod and let settle. After the material has fallen to the bottom,
decant the liquid, and fill with fresh water. Repeat the operation
until the water no longer shows an acid reaction. A portion of the
deposit may now be examined, and if not clean, boil the deposit with
tincture of soap and water in equal parts, decant, wash, first with
water, then with stronger ammonia water, and finally, with distilled
water. This usually leaves the frustules bright and sharp.--National
Druggist.

RED INDELIBLE INK.--It is said that by proceeding according to the
following formula, an intense purple red color may be produced on
fabrics, which is indelible in the customary sense of the word.

No. 1.
Sodium carbonate 3 drs.
Gum arabic 3 "
Water 12 "

No. 2.
Platinic chloride 1 dr.
Distilled water 2 oz.