VARIOUS SOLUTIONS

Boracic Acid Solution.—In the previous pages mothers are frequently told to use "a saturated solution of boracic acid." A saturated solution means that the water in the solution has dissolved all of the product that is put into it that it is capable of dissolving. When boracic acid is put into water, the water will dissolve it up to a certain point; if you add more the boracic acid will not dissolve; it will float if it is in the form of powder, or it will remain at the bottom of the glass if it is crystal—in other words the water is saturated to its limit and the solution is known as a saturated solution.

The strength of a saturated solution of boracic acid is as follows:—

Boracic AcidOunces1-1/2
Hot Sterile WaterPints2

which means that 2 pints of hot water will completely dissolve 1-1/2 ounces of boracic acid. If any more boracic acid is added the water will not dissolve it because it is already "saturated." Inasmuch, however, as boracic acid is harmless, it is perfectly safe to use the liquid part of a solution which contains some undissolved acid.

A saturated solution is used in the eyes after it is strained.

Normal Salt Solution.—A normal salt solution is made in the following proportions:—

Sodium Chloride (ordinary table salt)Grains128
Sterile WaterPints2

Normal salt solution is much used in irrigating the bowel. A mother may safely use it in the proportion of one heaping teaspoonful to two quarts of water—two quarts being the size of the ordinary fountain syringe.

Carron Oil.—Lime water and raw linseed oil, equal parts. This mixture is much used in burns. It should be made fresh.

Thiersch's Solution:—

Salicylic AcidDrams1/2
Boracic AcidDrams3
Sterile WaterPints2

Thiersch's solution is a good, mild antiseptic solution, or wash.

Solution of Bichloride of Mercury (1 to 1000):—

Bichloride of MercuryGrains15
Common SaltGrains15
Sterile WaterPints2

Bichloride of mercury is one of the most powerful and poisonous drugs. Solutions made from it should never be used without special directions from a physician. In much weaker solutions than the above it is one of the best antiseptic washes known. It is used to disinfect wounds, for douches, and for various other purposes, but always by special direction of a physician.

Other solutions.—Frequently mothers are directed to use solutions in the proportion of 1 to 500, or 1 to 1000.

This means that there will be one part of the drug, or of the liquid medicine, to 500, or 1000 parts of water. For example if you were asked to make up a solution of bichloride of mercury in the strength of 1 to 4000, you would use one ounce of bichloride of mercury to four thousand ounces of water, or one grain of the mercury to four thousand drops of water,—one grain being equivalent to one drop.

Sometimes solutions are made up on the percentage basis. For example, a five per cent. solution of carbolic acid. In this case it would be necessary to take five ounces of carbolic to one hundred ounces of water, or five drops of carbolic to one hundred drops of water.