1The Lotion' generally is the external analogue of 'The Mixture.' Its functions are varied, but the introduction of the antiseptic system of surgery has somewhat narrowed the composition of this class of preparations. Handsel Griffiths says lotions are 'external applications or washes, generally consisting of simple solutions of medicinal substances, and usually applied by wetting a piece of linen'- not a precise definition, but it will suffice. Such simple solutions are exemplified by the following medicaments, the quantities appended being the proportions to each ounce of water which are usually prescribed:

When a lotion of any of these is prescribed and no strength is mentioned, the proportions in this table may be followed.

It is particularly important that solutions such as the foregoing should be dispensed perfectly free from sediment. Dispensers are sometimes tempted to use tap-water for lotions because 'it does not matter.'If any reaction takes place between the dissolved solids in the water and the medicaments, whereby a deposit forms, the lotion may, on application to a tender surface, cause considerable irritation. Some lead lotions are purposely opalescent, as there is a long-standing notion that the fine lead precipitate is a protective. Subjoined is a selection of prescriptions which illustrate difficulties frequently encountered by dispensers.