Some homoeopathic physicians have tried to mix two remedies, one of which seemed homoeopathic to one portion of the symptoms, and the other to the remaining portion; but the results did not answer their expectations, and all good homoeopathic physicians were soon convinced that such a course would have occasioned the ruin of true homoeopathy, and would have degraded our practice far below the practice of the old school.

It would be as pernicious both to our patients and practice, to mix our remedies, as it is useful in many complicated cases, to use two remedies alternately at suitable intervals. This alternation may be much more rapid in acute than in chronic diseases. In the former the power of a dose is soon spent, in the latter, on the contrary, the functions of the organism are either carried on naturally, or they are too slow or even entirely suppressed. We will illustrate this by a few examples.

Scarlet fever and purpura miliaris are frequently found complicated; to the former corresponds Bellad., to the latter Aconite, both of which remedies may be given in alternation every three hours, to the great advantage of the patient. Dulcamara and Belladonna may be advantageously alternated in angina, when either of those remedies seems to be homoeopathic to the symptoms. The erethism to which consumptive patients are liable, frequently requires the use of Aconite, Acid, hydroc, Laurocerosus, etc., as intercurrent remedies, and it is good practice constantly to employ one of the latter remedies in alternation with the principal specific as long as the erethism lasts. In croup, Aconite and Spongia, or Spongia and Hepar have been alternated with great advantage by a number of physicians.

The sixth fundamental principle, as formerly established by Hahnemann, is, not to give a second dose of the same remedy or to administer a different remedy until the former shall have spent all its power. He deduced this maxim from the fact that many remedies act for days, weeks, and even months. Having at first an implicit faith in that maxim, homoeopathic physicians never thought of modifying it in the least. This maxim, however, being an important rule in practice, a number of experiments were instituted to verify it, and it was found that the frequent and successive repetition of a dose of the same remedy was not only useful but necessary to a cure. Even in the first edition of this work the repetition of the dose was adverted to as necessary in some cases, but at that time it was considered an exception to the rule. A repetition of the dose was considered necessary especially in those cases which improved after the first dose, but seemed to relapse into their former condition after the lapse of a few days. Recently the repetition of the dose has become a universally acknowledged rule, and even those physicians who are in the habit of using the highest potencies, do not always administer the whole pellet at once, but dissolve it in water and give one spoonful, or two or three of the solution for several days in succession. The necessity of repeating, the dose in many cases having been keenly felt, and that necessity having been established by the observations of a number of physicians, attempts have been made to regulate that repetition by rules. For instance, it is necessary to repeat the dose if the first dose diminishes the violence, without changing the character of the disease, and if the violence of the attack ceases to diminish after a time. If a second dose effects no farther change but simply prevents the disease from returning to its former violence, this is a certain proof that the organism has become accustomed to the influence of that medicine. If, however, that same medicine continues to be indicated, in that case a lower potency requires, to be administered, and to be continued until reaction has evidently set in, which ought not to be disturbed by another dose. If the reaction should cease before the cure is effected, in that case either the same or another more suitable remedy has to be administered.

It is universally conceded that the dose ought to be much less frequently repeated in chronic than in acute diseases where the vital process is carried on much more rapidly than in the former, and where, consequently, the vital powers are much more speedily exhausted. The repetition of the dose cannot be determined by fixed rules, and has to be left to the tact and judgment of the physician; of course he ought to . possess the talent to judge with discretion. If highly sensible and active organs are affected, the dose will have to be repeated more frequently, because its power will be spent much more rapidly, as is the case in inflammatory and typhoid diseases. In such diseases the effects of the remedy are perceived very soon, and the dose admits of a speedy repetition. If the effects are not soon perceived, we may conclude with certainty, that either the potency or the remedy was badly selected. In chronic affections the effects of the remedy ought to be perceived in forty-eight or at latest in seventy-two hours; if they are not, the remedy is either not homoeopathic to the disease or the potency was not adapted to the susceptibility of the organism.

If by repeating the dose an essential change is effected in the symptoms, this change may be considered a proof that the medicine is no longer homoeopathic to the disease; if circumstances permit, the exhibition of a new remedy may be delayed twenty-four or forty-eight hours; if the change of symptoms should indicate danger, a new remedy ought to be administered immediately. The dose ought not to be repeated when the disease passes into a new stage, for instance, in scarlatina, after the disease has assumed a new form by metastasis; in croup, when the disease has passed from the inflammatory stage to that of effusion; * in smallpox, when the suppurative stage has commenced, etc. These new forms of the disease require new remedies, which are to be repeated if necessary.