166. ℞. Olei Amygdal: f℥j
Acaciæ gummi ʒiij =M.N.=
tere simul, et dein gradatim adde
Aquæ destillatæ f℥vi =O.=
Syrup: Rhæados f℥ss =O.=
Fiat Mistura, de qua sumantur Cochlearia duo ampla ter, quaterve,
indies.
167. ℞. Olei Amygdal: fʒvj =I. }=
Liquoris Potassæ ♏︎L =}=
Aquæ Rosæ f℥viiss. =N.=
Fiat Mistura, ut supra capienda.
168. ℞. Mistur: Amygdal: f℥j =}=
Potassæ Carbonatis gr. x. =I.K. }=
Syrupi Rhæados fʒj =}=
Ft: haust: cum cochl: Succ: Limon: =}=
in impetu effervescentiæ sumend:
_Demulcent & Febrifuge._
169. ℞. Pulv: Cetacei
Pulv: Trag: comp: āā ℥ss =B.=
Syrupi Papaveris q. s. =N.O.=
Misceantur, et fiat Linctus. Dosis cochl: minimum subinde.
170. ℞. Cetacei ʒij
Pulv: Trag: comp: ʒj =}=
Syrup: Papaveris =B. } B.=
Syrup: Tolu: āā fʒij =}=
Confect: Ros: ʒvj =}=
Potassæ Nitratis ʒss =G.=
Fiat Electuarium, de quo capiat ad nucis moschatæ magnitudinem.
171. ℞. Cetacei ʒij
Vitelli ovi dimidium =}=
Syrupi f℥ss. =} B.=
Aquæ Cinnamomi f℥ij =}=
Aquæ destillatæ fʒiv =}=
Fiat Mistura, de qua capiat æger cochleare amplum frequenter.
172. ℞. Amyli ʒiij
Aquæ ferventis f℥iv. =L.=
Solve pro enemate, et adde,
si opus fuerit,
Tinct: Opii fʒss =G.=
173. ℞. Decoct: Lichenis oss
Sumatur quotidie, cochleatim,
instar potus communis.
SUPPLEMENTARY FORMULÆ
FOR CERTAIN REMEDIES
NOT INCLUDED IN THE PHARMACOPŒIA.
1. ℞. Acid: Hydro-cyanic: dilut: ♏︎v
Mist: Amygd: f℥iv =} O.=
Syrup: Tolutan: fʒj =}=
Fiat Mistura, de qua sumatur Cochleare unum amplum tertia quaque hora.
2. ℞. Acid: Hydro-cyanic: dilut: ♏︎xij
Tinct: Digitalis fʒss =F.=
Aquæ Cinnamom: f℥vss =O.=
Sumatur Cochl: unum amplum quartis horis.
3. ℞. Acid: Hydro-cyanic: dilut: fʒj
Aquæ Rosæ f℥iss
Sit pro lotione contra Impetigines utend:
4. ℞. Morphiæ Acetatis gr. xij
Aquæ destillat: f℥j =N.=
Acid: Acetic: dilut: ♏︎v =L.=
Spir: Rectificat: fʒj =P.=
Sumantur guttæ x–xx, ad dolorem leniendum, et somnum conciliandum.
5. ℞. Iodini ℈ij
Spir: Rectificat f℥j
Solve et fiat Tinctura.
℞. Tincturæ Iodini ♏︎v.
Aquæ destillat: f℥j =N.=
Sumr: guttæ x ter quotidie.
6. ℞. Quinæ Sulphat: gr. ij
Acid: Sulphuric: dilut: ♏︎ij =L.=
Aquæ destillat: f℥j
Fiat Haustus, bis terve de die sumend:
OF THE
MEDICINAL DYNAMETER.
This instrument is capable of showing, on mere inspection, the absolute
as well as relative strengths of the different Officinal Preparations of
the Pharmacopœia. The active Principles, or Medicinal Bases, are
distinguished by CAPITAL LETTERS, placed in coloured compartments, and
each Officinal preparation is marked by a line corresponding in colour
with that of its active ingredient. Where a preparation contains two
active ingredients it is distinguished by two coloured lines, as may be
seen in the _Pulvis Ipecacuanhæ 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, immediately
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 coincides 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 Ipecacuanhæ compositus_? By
having brought this preparation to 5, we shall see ½ opposite to Opium,
denoting that such a number of grains contains half a grain; for, unless
it be otherwise expressed, the figures denote _grains_ for the solids,
and _minims_ for the liquids. And, since the number opposite to the Base
denotes the absolute quantity of it contained in those several
proportions of its Officinal compounds, which are expressed by the
respective numbers opposite to each, it follows that these latter must
all be medicinally equivalent to each other; thus we have seen that 5
grains of _Pulvis Ipecacuanhæ compositus_ contains ½ 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 show the
number of grains of each which contains ½ grain of opium, and
consequently those numbers must be all Equivalents; thus 2½ grains of
_Pil. Saponis comp:_ 5 grains of the _Pulv: Corn: ust: cum Opio_, 9½
minims of Tinctura Opii, 10 grains of _Pulv: Kino comp:_ 18 grains of
_Confectio Opii_, 20 grains of _Pulv: Cretæ 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
system of Equivalents will be found of much practical value to the
practitioner, by enabling him, at once, to substitute one preparation
for another, without the risk of altering the dose of its active
ingredients. Suppose, for example, a patient had been taking 8
fluid-drachms of _Mist: Ferri Comp._ and that we wish to give the same
quantity of Protoxide of Iron in the form of the _Pil: Ferri comp_. we
have only to bring the mixture in question to 8, and we shall see 13½
grs. are equivalent, both these quantities of the respective
preparations containing ⅔ds of a grain of protoxide, or a little more
than a grain of the Proto-carbonate. Suppose again, that we have an
acetic acid of sp. gr. 1.059, and that we wish to produce, by its
dilution, two fluid-drachms, or any other quantity, of acid having the
strength of distilled vinegar, the question is, what are the proportions
of water and strong acid to be employed. We have only to bring the
Acidum Aceticum of 1.059, to 120, i. e. to fʒij, and the number opposite
to the strong acid, _viz._ 16, is its equivalent, if therefore we take
16 minims of it, and dilute it with 104 minims of water, we obtain the
mixture required.
Those who are acquainted with the sliding rule of Gunter, or the
chymical scale of Dr. Wollaston, will immediately perceive that the
present circular scale is divided upon the same logometric principle,
and that the mechanical addition and subtraction of ratios here
performed by juxta-position, corresponds in effect to the multiplication
and division of the numbers by which the ratios are expressed in common
arithmetical notation. It is not necessary that I should trouble the
reader with the numerous difficulties and embarrassments which have
opposed themselves to the practical success of this instrument. They
have, after repeated failures, been at length overcome, except perhaps
with regard to a slight central error, which as it is found in the most
accurate brass instruments, could not be avoided where pasteboard alone
had been employed. The error, however, is not of the slightest practical
moment, not occasioning the difference of a hundredth part of a grain.
The proportions of active matter, in the several preparations of each
class, have been, in general, derived from the best authorities,
although in many cases they have been deduced from experiments expressly
instituted for the occasion.