Some prescribes appear to imagine that menthol is soluble in water, perhaps because the crystals look salt-like. Never hesitate to filter watery solutions containing in suspension particles of menthol or thymol if they are to be used as gargles, and if the prescriber cannot be got at to alter the prescription. This, of course, does not apply to inhalations. The use of camphor with menthol in a preparation such as the foregoing obtains a larger quantity of the menthol in solution. The two substances should be rubbed together first. If camphor-water had been ordered instead of plain water, the procedure would have been to rub the camphor equivalent to the camphor-water with the menthol, then add the glycerin, and lastly the alum and chlorate dissolved in the requisite water.

Pix Liquida

When prescribed with alkali {e.g., liquor potassae) and water, boil all together for half an hour, replacing water evaporated, cool, and strain.

Resorcin

Any opportunity should be taken of calling the attention of prescribers to the fact that resorcin solutions colour the hair. A lotion containing mercuric chloride, ammonium chloride, resorcin, eau de Cologne, and water changed silver-white hair into a reddish-yellow colour. On trying to bleach the dyed hair with hydrogen peroxide it became green !