This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol2", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
This term, signifying from its origin destroyers of parasites, is here employed precisely in its etymological meaning. The human system is infested, both within and upon the surface, with numerous living beings, animal and vegetable, of very different grades of organization, which much interfere with its well-being, and often act fatally upon it. These have recently risen into much greater importance than ever before, in consequence of discoveries which have, with great probability of truth, though not yet with absolute certainty, traced some of our most destructive diseases to such an origin. On this particular branch of the subject there will be occasion to treat more fully under the antizymotics; and, for the present, taking for well founded the opinion which ascribes to the fermenting processes a potent influence in the production and maintenance of disease, and considers these fermenting processes as essentially connected with certain microscopic organisms, I shall proceed to arrange the substances belonging to the class of parasiticides in accordance with this view. As there are two sets of parasites, one of sufficient magnitude to be obvious to unaided vision, the other so minute as to require the microscope to render them visible, there are sufficient grounds for dividing the agents intended for their destruction into two corresponding groups. Hence, under the parasiticides we have two sub-classes, one embracing the remedies used against visible parasites, with the general title of anthelmintics, the other those which have been found destructive of the invisible, designating them as antizymotics, because it is in the prevention of fermentation that they exhibit their most extraordinary powers.