In the various preparations contained in the first part of this work, constant reference is made to weights and measures, temperature, etc.; and it is therefore important that these should be clearly understood.

In the British Pharmacopoeia the weights employed differ from those previously used in any other similar work; the apothecaries' weight of the London and Edinburgh Pharmacopoeia has been abolished, and the avoirdupois pound and ounce adopted, together with the troy grain; the subdivisions of the avoirdupois ounce introduced into the Dublin Pharmacopoeia in 1850, have likewise been discarded, and there is now no intermediate weight between the ounce and grain. The measures remain the same as those of the London, Edinburgh, and Dublin Pharmacopoeias. The weights and measures of the British Pharmacopoeia are as follows:-