Sodii Arsenas

Triturate with milk sugar and mass with glucose syrup.

Sodii Bicarbonas

Three grains of dry bicarbonate of sodium with 1 grain of powdered ginger can be made into a very workable mass by the addition of 1 grain of tragacanth and water or mucilage sufficient to make a mass. The pills both roll well and keep well.

Sodii Nitris

Occasionally ordered in pill. Care should be taken not to use any acid excipient, else nitrous fumes will be liberated; even extract of gentian has done this, the pills swelling and cracking. Kaolin ointment is the best excipient.

Sodii Sulphidum

Treat exactly like calcium sulphide, but in such a case as the following resin ointment is the best excipient:

Omit the extract of gentian, as any moisture will make the salicylic acid react with the sulphide, liberating sulphuretted hydrogen; hence the use of a fatty excipient.

Sodii Taurocholas

This substance is so deliquescent that it may be massed by simply beating in a mortar with the smallest possible quantity of proof spirit. The pills are coated with melted salol or keratin solution.

Strychnina

Triturate well with sugar of milk before massing.

Sulphonal

Masses well with glycerin of tragacanth, but pills are the worst possible form for administering this hypnotic.

Sulphur

Rarely prescribed in pill form. The following is a good test of dispensing skill:

Ft. pil. Mitte sex.

Gum acacia must be avoided, and the sulphur and chalk should be quite dry. Triturate the sulphur lightly with the calomel, add the chalk stir, and mass with glycerin of tragacanth.

Thymol

May be treated like menthol.

Zinci Oxidum

Makes a good mass with dispensing-syrup.

Zinci Phosphidum

Triturate well with sugar of milk (1/2 grain for each pill) and mass with glycerin of tragacanth.

Zinci Valerianas

Add a small quantity of acacia, and mass with spirit. This gives a mass requiring quick manipulation, but yielding excellent results. Glycerin of tragacanth also makes a good mass with the addition of a little inert vegetable powder. For behaviour of the valerianate with caffeine citrate, see page 103.

No. I. is softish on mixing, but gets firmer on standing, and only requires kieselguhr to mass it. No. II. makes a nice mass with proof spirit.

By intelligent application of the principles involved in the foregoing paragraphs dispensers should be able to overcome difficulties in connection with allied substances.