to act on the lower bowel, when it is insoluble or nauseous, or when it is difficult to prescribe in the liquid form. Kaolin is the best basis for substances, as potassium permanganate, which are decomposed by contact with organic matter.

Oils, and volatile, deliquescent or bulky substances should not be prescribed as pills, as they require much solid excipient; nor should pills be used for substances required to act immediately. Insoluble or very disagreeable powders are often given in cachets.

Abbreviations should be employed as little as possible. Serious mistakes have happened because the abbreviations have been ambiguous. The following are especially to be avoided:

Acid. Hydroc. (may be Acidum Hydrochloricum or Acidum Hydrocy

Ex. Col.

Hyd. Chlor.

Hyd.

Sulph.

anicum).

(may be Extractum Colchici Cormi or Extractum

Colocynthidis).

(may be Calomel, Corrosive sublimate or Chloral

hydrate).

(may be Hydrargyrum, Hydras, Hydriodas, Hydrochloridum, Hydrochloras or Hydrocyanicus).

(may be Sulphide, Sulphate, or Sulphite).

Sometimes the signature is written in Latin, and it is often abbrevi

ated.

The following Latin phrases with their abbreviations are commonly used in the writing of prescriptions:

Vehic.
Ver.
Vesp.

Vehiculum

Verus

Vesper

menstruum.
genuine.

the evening.

In Great Britain and in the United States it is always understood, unless otherwise stated, that the preparations are those of the Pharmacopoeia.

Ad. The prescriber should be use this word before the vehicle. tion given on p. 42, the bulk of the mixture would have been nearly 315 c.c. (101⁄2 fluid ounces) and the amount of the ingredients in each dose would have been less than was intended.

careful in deciding whether or not to If it had been left out in the prescrip

Dispensing the Prescription.-The dispenser should bear the following rules in mind: (1) Read the prescription through first. (2) Next write the directions, so that they have time to dry. (3) Solution by heat should not be used if more of the salt is ordered than will dissolve in cold water. In such case it must be suspended. (4) With fluids, measure them in such an order that the measuring glass shall be finally rinsed out with vehicle. (5) Use glass scale pans. (6) Clean and put away everything directly after use. (7) If in the slightest doubt, ask the prescriber. (8) If finally the prescription contains any insoluble matter, label "Shake the bottle." (9) If the medicine is very poisonous, label it as such and use a distinctive bottle. (10) If for outward application only, label it as such. (11) In dispensing substances chemically incompatible, if there is any likelihood that the new body formed is dangerous, communicate with the prescriber before dispensing (e. g., Potassium Iodide prescribed with Spiritus Etheris Nitrosi forms free iodine; alkaloids are precipitated by alkalies). Should there be no such reason against dispensing the prescription (e. g., Liquor Potassii Hydroxidi and Ferrum Dialysatum), keep the incompatibles as far apart as possible by diluting each with the vehicle before mixing.

PART I. INORGANIC MATERIA MEDICA.

DIVISION I: THE NON-METALS.

GROUP I.

THE HALOGENS.

Chlorine, Bromine, Iodine.

I. CHLORUM.

CHLORUM.-Chlorine. Cl= 35.18.

This gas is not official under its own name, but is obtained from two sources of it, viz., Hydrochloric Acid and Chlorinated Lime.

Preparations.

1. LIQUOR CHLORI COMPOSITUS.-Compound solution of Chlorine. An aqueous solution of Chlorine (Cl = 35.18) containing about 4 per cent. of Chlorine with some chlorinated products and Potassium Chloride.

SOURCE.-Pass cold distilled water, in successive portions, into a flask containing freshly generated Chlorine gas. The gas is obtained by heating Hydrochloric Acid, 18; and Potassium Chlorate, 5. 6HCI +KCIO, 3Cl2 + 3H2O + KCl.

=

CHARACTERS.—A clear greenish-yellow liquid, having the suffocating odor and disagreeable taste of Chlorine. This solution should be freshly made when wanted.

INCOMPATIBLES.-Lead and Silver salts.

Free Chlorine is contained in Acidum Nitrohydrochloricum Dilutum. Dose, 4 c.c.; 1 fl. dr.

2. CALX CHLORINATA (Calx Chlorata, U. S. P., 1890).-Chlorinated Lime. Chlorinated Calcium Oxide. Synonym.-Bleaching pow

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