Elements of pharmacy, materia medica, and therapeutics / by William Whitla.

  • Whitla, William, 1851-1933.
Date:
1903
Catalogue details

Licence: In copyright

Credit: Elements of pharmacy, materia medica, and therapeutics / by William Whitla. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

    25/644 (page 21)
    bottles, with patent stoppers, have been devised to facihtate dropping; but, as a rule, every requirement is met by the Fig. 4. above plan. The student should remember that a drop is a vague and indefinite quantity, supposed to be identical with a minim, which it seldom is. Elaborate tables have been pre- pared, showing how many drops of certain liquid preparations are found to correspond with one drachm : thus it is generally stated that there are 120 drops of tincture of digitalis or lauda- num in one fluid drachm, and 45 of Prussic acid in the same bulk. It is, however, well known that the number and size of the drops depend, not so much upon the nature of the liquid, as upon some accidental circumstances—as the shape and size of the stopper, or especially tlie shape of the lip of ihe bollle, and the degree of moisture about it, &c. The practice of ordering drops should be entirely given up, and minims directed to be measured instead, unless, perhaps, when two or three drops of a flavouring essence are ordered in a mixture. Hydrocyanic acid is best measured with a long graduated syringe, and many other liquids could be treated in a similar way with advantage. A graduated pipette with a small India-rubber teat or bulb at its blunt extremity answers most cases.