Volume 1

A textbook of pharmacology, therapeutics and materia medica.

  • Brunton, T. Lauder (Thomas Lauder), 1844-1916.
Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: A textbook of pharmacology, therapeutics and materia medica. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    192/816 (page 136)
    be graphically represented by a spiral, the terminal members of which are potassium and barium, and these two are, to a certain extent, connected by ammonium as an intermediate link. The effect of one member of one of these groups may be diminished or increased by the subsequent application of another. Potassium shortens the elongated curves caused by barium, calcium, sodium in large doses, and lithium, and reduces the con- tracture which these substances cause. The veratrine-like curve of barium is counteracted by almost all the substances which produce a shorter curve than itself. Action of Drugs on Muscle is Relative and not Absolute. In considering the action of drugs on muscle, the first point which comes clearly out is that the action of a drug on the muscle is not absolute, but merely relative. Thus veratrine and salts of barium are not to be regarded as absolute muscle- poisons—they are only poisons under certain conditions of quantity and of temperature. An exceedingly small dose of veratrine, instead of acting as a poison to muscle, acts rather as a food, and restores it when exhausted. Caffeine likewise in small doses has a restorative action, while in large doses it is a powerful poison. Veratrine and barium in moderate doses and at moderate temperatures are powerful muscular poisons, but at low temperatures and at high temperatures their action is to a great extent, or even completely, abolished. Nay more, moderate quantities of barium salts at moderate temperatures are poisonous to the normal muscle, but they are restorative to the muscle whose composition and functions have been already altered by rubidium. Acids and alkalis also produce an effect on muscle, but their effect depends upon whether they are applied to the normal muscle or to one previously treated with a substance having an opposite reaction. It is evident, then, that the whole question of the action of drugs on muscle is one involving the relation of the drug to the muscle at the time of application, and we must expect that if the temperature is different from the normal, or if the composition of the muscle should vary, the action of the drug will vary like- wise. Now the composition of all the muscles in the body is not the same, as has been shown by Toldt and Nowak,1 and the composition of the ash obtained by the combustion of different animals is also different, as has been shown by Lawes and Gilbert.* * We may therefore expect that muscular poisons will not act alike at the normal temperature and in febrile condi- tions, nor alike upon all the muscles of an animal; nor will they 1 Quoted by Seegen, Wien. Akad. Bcr. lxiii. Abt. ii., 11-43. * Proc. Boy. Soc., xxxv., p. 344.