The illustration, page 83, shows a dropping-bottle which is useful for adding water to pill-masses. An eye-drop bottle, made by inserting a piece of glass tubing, with capillary point, in a perforated cork fitted to a phial or small flask, or a Chalk's drop-bottle, is equally good. At well-appointed dispensing-counters several bottles containing syrup, mucilage, glycerin and water, glucose syrup, tragacanth paste, and other excipients are kept. The illustration on the next page shows a suitable bottle for the purpose.

When fluids require to be added to form a pill-mass, it is risky to add them direct to the mixed powders from a stockbottle, as one may pour in too much; so, when a dropper is not available, drop the fluid excipient first on to the point of the spatula, and from it to the mortar in the necessary quantity.

Pill-masses containing vegetable powders take a few minutes to absorb the added water (as already noted), so that a nice plastic mass may become quite crumbly in ten to fifteen minutes. It is customary, therefore, to make such powders as rhubarb into a rather soft mass at first. If the exact quantity of water or syrup required for massing a powder be known, the pills may be made of smaller size, and in less time, by adding the required quantity at once, and rapidly mixing and cutting before the mass has become too firm by absorption. The addition of the excipient little by little generally adds much to the labour, and not infrequently much also to the size of the pills. This applies to soft excipients, like extracts, as well as to liquids.

If the quantity of extract ordered would make the mass too soft, the dispenser must, if the extract be a potent one, either use it in a drier state or add some inert powder to it. In other cases it is common to use some powder of the same drug- eg., if 20 grains of extract of gentian were ordered, and it would make too soft a mass, one might use 10 grains of extract with 10 grains of powdered gentian. The best plan, however, is to diminish rather than increase the bulk of the pill, so that when an extract is too soft it should be evaporated to a proper consistence; and for this reason every pharmacist should have some simple and ready appliance for accomplishing this without risk to the extract. A pill-tile placed over a small water-bath is convenient and rapid. Experience indicates that it is well to make an allowance of 3 or 4 per cent, for loss, as it is practically impossible to scrape all the dried extract off the drier. It is well to remember that some extracts are highly hygroscopic after evaporation, and if allowance is not made for this, pills massed with them may become semi-fluid on keeping.

Never use the same spatula to scrape the mass from the pestle and to dip into the extract-pot.

Excipient-Bottle.

An empty 1-oz. citrate of iron and quinine bottle. The cover made of sheet indiarubber, a little larger than the mouth of the bottle, and the dipping-rod of glass.