(from medeor, to heal). A medicine has been styled any substance capable of changing the state of the solids and fluids of the human body, so as to prevent the increase of disease,or restore health. This definition is, however, both erroneous and imperfect. Terror will prevent a fit of epilepsy, or the attack of an intermittent. Sailing will produce a salutary discharge from the stomach, while neither changes the state of the solids or fluids. It is, indeed,by no means clear that any medicine, except those employed in the cure of chronic diseases, produces any considerable change in either; and we have found, when we spoke of the arrangement of the articles of the materia medica, that medicines chiefly altered the functions of the bodys or the balance of. the circulation. The definition seems to have been chiefly intended to distinguish medicines, from aliment on the one side, and from poisons on the other. The former was supposed to add to the bulk, or to repair the unavoidable losses; the latter to destroy life. Aliment, however, properly regulated, often removes diseases and the most virulent poisons in smaller doses are very useful remedies; so true is the canon of Linnaeus, that"medicines differ from poisons, not in their nature, but their doses."
Though we have treated of the different methods of investigating the power of medicines, it must still be acknowledged that we owe our knowledge of the most powerful remedies to chance, or to the pursuit of objects very different from the results which have been experienced. Chemistry, it is said, has elaborated many remedies, but discovered none. Yet in the pursuit of the imaginary elixir, to prolong life to an indefinite term, some medicines have been discovered, though among these we can neither reckon mercury nor antimony, whose powers were elicited by chance. A happy boldness, or a random experiment, has often added essentially to our stock; but inductive reasoning has only contributed to correct the hasty views of the indiscreet, or to regulate the eagerness of the too sanguine experimentalist.
Modern practice employs few remedies. Yet, as we have more than once shown, simplicity of prescription is the delusive meteor that has sometimes led us astray. (See Combination of medicines.) In general, however, we agree with an author, whose name has escaped us, that long formulae are proofs of either ignorance or deceit.
It has been doubted whether there are any specific-medicines. As usual, the question requires only to be explained to approach at least to a decision. If it be meant whether a specific stimulus exists, the position must be granted. If, then, there be such, the medicine which possesses this stimulus is, to a certain degree, a specific; but if it be meant whether any medicine can cure a disease by such peculiar inherent powers as are neither warranted by its general properties, or our knowledge of the nature of the complaint, we must hesitate in our answer. The number of supposed specifics, by a more careful investigation, have not been found peculiarly powerful in the disease to which they were supposed to be exclusively adapted; and we have only left on the list the Peruvian bark and mercury in intermittents and the lues venerea. The former, however, has now lost this proportion of its credit, since other tonics, particularly the arsenic, is found of equal or superior efficacy. The pretensions of mercury to the character of a specific we have lately investigated (see Lues); and when we consider the history of the numerous individuals supposed to belong to this class, we are disposed to conclude, that, as usual, ignorance is the parent of our admiration. Had we any medicine of efficacy to compare with mercury we should discover its relations, and, of course, the cause of its general utility. We have made some steps in this inquiry in the article just quoted.
Universal medicines are now only seen in the columns of a newspaper, or a quack bill. The numberless inconsistent qualities attributed to a patent medicine would almost fix it in this rank; but its real utility is soon seen, if we trace the leading diseases for which it is recommended; and we then find it a common medicine decorated with a pompous title, if it be not an inefficient compound, whose sole merit lies in its name, in its extravagant recommendations, and the credulity and folly of those whose abilities, if exerted, would soon point out the fallacy. See Quacks and Quack medicines.
The various distinctions of medicines into general and topical, curative, palliative, or preservative, are sufficiently obvious, though little attended to at present, as the same medicine is now often used with each view. The bark, for instance, is a palliative in restraining the colliquative sweats in hectics, a preservative during the progress of a highly putrid epidemic, and a curative in intermittents.