442 
PHARMACEUTICAL WEIGHTS AND MEASURES. 
of 16 ounces troy, for the general purposes of commerce, would have proved 
abortive. The avoirdupois pound, with its subdivisions and multiples, are 
established in use throughout the whole of this kingdom, and the values of these 
weights are as clearly defined and well regulated by law as are the weights used 
in any other country. Our measures also have a simple relationship to the 
avoirdupois weights, and one could not properly be altered without altering the 
other. These weights and measures are fully applicable for all the ordinary 
purposes of commerce, but as the subdivisions of the avoirdupois pound do not 
extend below the sixteenth part of the ounce,-or avoirdupois drachm, this 
weight is inapplicable either for dispensing medicines or for selling precious 
stones and other costly articles. Hence the legislature, in such cases, allows 
the substitution, in the one case, of apothecaries’ weight, and in the other, of 
troy weight. If, in establishing what are now called the imperial weights in 
this country, the avoirdupois pound had been divided, as it appears originally 
to have been, into ounces, drachms, scruples, and grains, making the drachm 
part of the ounce, and the scruple^ part of the drachm, but making the 
grain part, instead of part as formerly, of the scruple, we should have had 
a system of weights which would have been applicable to all purposes, and would 
have rendered it unnecessary to sanction the use of any others. The only 
inconvenience attending the adoption of such an arrangement would have been 
that the legally-recognized grain would have been slightly reduced in weight. 
It will be recollected by some of our readers that a proposition to adopt such a 
division of the avoirdupois ounce for use in medicine was made some years ago 
by Dr. Wilson, of Edinburgh, and this proposition was so favourably enter¬ 
tained at one time by the Medical Council, that they determined to adopt that 
system of weights in the British Pharmacopoeia, but this determination was 
afterwards altered. It is certainly to be regretted that in the weights now 
ordered to be used in medicine there is not a simple relationship between the 
grain and ounce, and that there are no intermediate denominations of weight 
between those two. In prescribing, the scruple of 20 grains, and the drachm 
of 60 grains, are still used, and will no doubt continue to be so, and it is here 
that the drachm and scrapie are most required. With reference to the formulae 
given in the Pharmacopoeia for the preparation of medicines, there are a few 
cases in which the adjustment of the proportions of the ingredients used might 
perhaps have been effected rather more conveniently if the grain had been an 
integral part of the ounce, and there is certainly some apparent awkwardness 
in the formulae quoted by Professor Guibourt ; but it must be recollected that 
sets of grain weights are commonly kept from 10,000 grains downwards, divided 
decimally, and these are easily applied in cases such as the Professor refers to. 
But not only does Professor Guibourt object to the weights used in the 
British Pharmacopoeia, he appears still more strongly to object to our use of 
measures,—not of the particular measures ordered, but of any measures. He 
says, “ in my opinion, no instrument is comparable to a balance for determining 
exactly the quantity of a liquid, and I highly approve the directions of the 
later Prussian Pharmacopoeias in not allowing the measuring of liquids.” It is 
well known that in France the measure-glass is hardly ever used in pharmacy. 
In dispensing, as well as preparing medicines, liquids are weighed and not 
measured. In some cases there is no doubt that greater accuracy may be 
attained by the use of the balance than of the measure-glass ; thus, for instance, 
in the preparation of the diluted mineral acids, the quantities would be better 
adjusted by weighing than by measuring the strong acids ; but for the general 
purposes of dispensing or mixing liquid medicines, we doubt if the French system 
has any advantage over that adopted in this country. The French pharmacien, 
in dispensing a mixture, begins by putting the bottle into a balance, and coun¬ 
terpoising it: then he weighs the liquids in the bottle, adding them one after 
