Observations on medical weights and measures.

  • Wilson, Charles.
Date:
[1859?]
Catalogue details

Licence: Public Domain Mark

Credit: Observations on medical weights and measures. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

    22/26 (page 214)
    the avoirdupois system, to the extent that it adopted that system for all denominations of weight above the grain. But, unfortunately, this change lost much of the merit which attaclied unquestionably to Its motive, through tiie circumstance that it seemed only to vary the difficulty by eluding a part of it; for, in attaching, as a conces- sion to a long-established infraction, a hitherto unrecognised value to the larger denominations of weights, while retaiiiing the troy grain as the real basis of the system, so far from tliere being a true amalgamation, the actual tendency was to give the appearance of a rule to that practice which was still only arbitrary, and thus to lend the sanction of a new authority to what remained a confused and defective arrangement, resting upon two different, and, in the strict sense, radically and essentially incompatible standards. This is best shown by the fact, that the troy grain could be converted into no ahquot part of the avoirdupois ounce, or of its sub-multiple the drachm ; and the expressed value of the former (gr. 437*5), or of the latter (gr. 54-68), or of the associated scruple (gr. 18-22), carried with each so much of an air of unscientific indefiniteness, and of an assurance of practical intricacy and inconvenience, through the com- pulsory introduction of such fractional numbers into matters which, in ordinary life, must often become the subject of rapid calculation, that the plan, however partially efficient in result, and wholly excel- lent in intention, seemed little fitted otherwise to invite a general concurrence. But if the result of this intermingling of standards, thus incapable of any perfect blending, with its attendant breaking lip into fractional parts of the ounce, drachm, and scruple, evinced the unaptness of the current troy grain for becoming a proper basis for the avoirdupois weight, or for being easily assimilated with that weight, the difficulty becomes at once obviated by reducing the troy grain, in the manner proposed, to 091145 of its present value, and by assuming this as the medicinal grain. We now acquire for the system a fundamental unit, fit to take position as an integral part of any of its divisions ; and thus it necessarily follows, that what is only an apparently slight change in itself becomes really endowed with virtue enough to remove entirely the existing confusion, imparting to the arrangements everywhere the dignity and consistency of a uni- form system, and ensuring a rigid scientific exactness and parallelism to all the operations of pharmaceutical metrology within its own limits, while binding it successfully in equally congruous relations with the ordinary transactions of commerce. With the adoption, then, of this modified fundamental unit, we complete a system of weights by which the avoirdupois pound, with its statutory division into 16 ounces, is retained for exclusive use in medicine; but the ounce, as we have already indicated, will be divided into 8 drachms, each, therefore, containing two of the former avoirdupois drachms, a denomination of weight so little in use eveiy- where that it may be almost said to have become obsolete. How- ever, should it still be thought necessary to recognise its existence,