incompatible, for while the alkali, through the medium of the circulation, stimulates the secreting organs of the kidneys, the foxglove may, by its sympathetic action, rouse the energy of the absorbents. In the administration of diaphoretics we shall frequently derive additional force, as well as certainty, by combining those which act by relaxing the cutaneous emunctories, with those which prove diaphoretic by imparting a general increase of momentum to the blood. B. _By combining Medicines which have entirely different powers, and which are required to obviate different symptoms, or to answer different indications._ Arrangements constructed upon this principle constitute some of the most valuable remedies with which we are acquainted; they are in general _extemporaneous_, because their value depends upon their being varied and modified according to the symptoms and circumstances of each particular case. The following general elucidation of the subject may serve to demonstrate the nature and importance of such combinations. PURGATIVES _with_ ANTISPASMODICS. The practice suggested by Drs. Stoll and Warren, in the treatment of _Cholica Pictonum_, affords a striking example of the expediency of combinations of this nature. It is found in that disease, as well as in others attended with spasmodic constriction of the intestinal canal, that purgatives produce no effects unless the spasm be allayed by combining them with _Opium_, (_see Form. 71, 75, 76_,) it is from such a cause that the purgative so popular with tailors and shoemakers, and which consists of _Aloes_ with _Sagapenum_ or _Galbanum_, affords such prompt relief in the spasmodic cholic to which they are subject. PURGATIVES _with_ TONICS. In the exhibition of cathartics how frequently it occurs in practice that the patient’s strength will hardly allow the evacuation; in such a case the addition of _steel_ as a roborant (_Form. 72, 92, 93_,) or even of _æther_, or _ammonia_, as a diffusible stimulant, is strongly indicated: the Cheltenham waters offer a natural combination of this character. So again in the cure of dropsy we have often two indications to fulfil—to evacuate the water, and to support the strength of the patient; hence the necessity of combining brisk and stimulating purges, such as _Scammony_, _Jalap_, &c. with active tonics, (83.) In the treatment of amenorrhæa the same medicinal arrangement is not unfrequently indicated. PURGATIVES _with_ MERCURIAL ALTERATIVES. In habitual costiveness, where there appears to be a deficiency of bile, a combination of _Pilula Hydrargyri_, with certain _Aloetic_ compounds, may prove serviceable; for while the latter remedy will, in the absence of bile, supply to the intestines a congenial stimulus, the former will tend to restore the bilious secretion by its influence upon the hepatic system. _See Form. 79, 81_.