Volume 4

Pharmacologia; comprehending the art of prescribing upon fixed and scientific principles; together with the history of medicinal substances / By J.A. Paris.

  • Paris, John Ayrton, 1785-1856.
Date:
1825
Catalogue details

Licence: Public Domain Mark

Credit: Pharmacologia; comprehending the art of prescribing upon fixed and scientific principles; together with the history of medicinal substances / By J.A. Paris. Source: Wellcome Collection.

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    OF THE MEDICINAL DYNAMETER. Tus instrument is capable of shewing on mere inspection, the absolute as well as relative strengths of the different Officinal Preparations of the Pharmacopeia. The active Principles, or Medicinal Bases, are distinguished by Cariran Lerrers, placed in coloured compartments, and each Offici- nal preparation is marked by a line corresponding in colour with that of its active ingredient. Where a preparation con- tains two active ingredients it is distinguished by two co- Joured lines, as may be seen in the Pulvis Ipecacuanhe comp. By this expedient the eye, at once, recognises the different classes of medicines ; all those for instance, coloured red are Opiates; those blue, Mercurials; green, Acetic acid; &c. The introduction of colours, moreover, immedi- ately indicates the basis to which any preparation refers, and thus prevents the possibility of doubt or confusion. If we wish to learn the actual quantity of active matter contained in any given proportion of a compound, we have only to turn the scale until the name of such compound coin- cides with the number in question, when the figure opposite to the basis solves the problem ; thus—how much opium is contained in 5 grains of the Pulvis Ipecacuanhee compositus 2 By having brought this preparation to 5, we shall see 4 oppo- site to Opium, denoting that such a number of grains con- tains halfa grain; for, unless it be otherwise expressed, the figures denote grains for the solids, and méinims for the li- quids. And, since the number opposite to the Base denotes the absolute quantity of it contained in those several propor- tions of its Officinal compounds, which are expressed by the respective numbers opposite to each, it follows that these lat- ter must all be medicinally equivalent to each other; thus we have seen that 5 grains of Pulvis Ipecacuanhe compositus contains 4 grain of Opium, if we turn our eyes to the other Opiate preparations we shall perceive that each has a different number opposite to it, these figures shew the number of grains of each which contain 4 grain of opium, and consequently those numbers must be all Equivalents ; thus 24 grains of Opio, 94 minims of 'Tinctura Opii, 10 grains of Pulv: Kino comp: 18 grains of Confectio Opti, 20 grains of Pulo: Crete comp: cum Opio, and 120 minims, or two fluid-drachms of Tinctura Camphor: comp: contain half a grain of Opium, and are consequently all equivalent to each other. This Rh ae Vi at PY