32     It is on such examples of domestic practice that Mr. M. Lux founds his so-called mode of cure by identicals and idem, which he calls Isopathy, which some eccentric-minded persons have already adopted as the non plus ultra of a therapeutic method, without knowing how they could carry it out.      But if we examine these instances attentively we find that they do not bear out these views.      The purely physical powers differ in the nature of their action on the living organism from those of a dynamic medicinal kind.      Heat or cold of the air that surrounds us, or of the water, or of our food and drink, occasion (as heat and cold) of themselves no absolute injury to a healthy body; heat and cold are in their alternations essential to the maintenance of healthy life, consequently they are not of themselves medicine. Heat and cold, therefore, act as curative agents in affections of the body, not by virtue of their essential nature (not, therefore, as cold and heat per se, not as things hurtful in themselves, as are the drugs, rhubarb, china, etc., even in the smallest doses), but only by virtue of their greater or smaller quantity, that is, according to their degrees of temperature, just as (to take an example from purely physical powers) a great weight of lead will bruise my hand painfully, not by virtue of its essential nature as lead, for a thin plate of lead would not bruise me, but in consequence of its quantity and massive weight.      If, then, cold or heat be serviceable in bodily ailments like frost-bites or burns, they are so solely on account of their degree of temperature, just as they only inflict injury on the healthy body by their extreme degrees of temperature.      Thus we find in these examples of successful domestic practice, that it is not the prolonged application of the degree of cold in which the limb was frozen that restores it isopathically (it would thereby be rendered quite lifeless and dead), but a degree af cold that only approximates to that (homœopathy), and which gradually rises to a comfortable temperature, as frozen sour crout laid upon the frost-bitten hand in the temperature of the room soon melts, gradually growing warmer from 32° or 33° (Fahr.) to the temperature of the room, supposing that to be only 55°, and thus the limb is recovered by physical homœopathy. In like manner, a hand scalded with boiling water would not be cured isopathically by the application of boiling water, but only by a somewhat lower temperature, as, for example, by holding it in a vessel containing a fluid heated to 160°, which becomes every minute less hot, and finally descends to the temperature of the room, whereupon the scalded part is restored by homœopathy. Water in the act of freezing cannot draw out the frost isopathically from potatoes and apples, but this is effected by water only near the freezing-point.      So, to give another example from physical action, the injury resulting from a blow on the forehead with a hard substance (a painful lump) is soon diminished in pain and swelling by pressing on the spot for a considerable time with the ball of the thumb strongly at first, and then gradually less forcibly, homœopathically, but not by an equally hard blow with an equally hard body, which would increase the evil isopathically.      The examples of cures by isopathy given in the book alluded to—muscular contractions in human beings and spinal paralysis in a dog, which had been caused by a chill, being rapidly cured by cold bathing—these events are falsely explained by isopathy. What are called sufferings from a chill are only nominally connected with cold, and often arise, in the bodies of those predisposed to them, even from a draught of wind which was not at all cold. Moreover, the manifold effects of a cold bath on the living organism, in health and in disease, cannot be reduced to such a simple formula as to warrant the construction of a system of such pretentions! That serpents' bites, as is there stated, are most certainly cured by portions of the serpents, must remain a mere fable of a former age, until such an improbable assertion is authenticated by indubitable observations and experience, which it certainly never will be. That, in fine, the saliva of a mad dog given to a patient laboring under hydrophobia (in Russia), is said to bave cured him—that "is said" would not seduce any conscientious physician to imitate such a hazardous experiment, or to construct a so-called isopathic system, so dangerous and so highly improbable in its extended application, as has been done (not by the modest author of the pamphlet entitled The Isopathy of Contagions, Leipzic: Kollmann, but) by its eccentric supporters, especially Dr. Gross (v. Alg. hom. Ztg., ii, p. 72), who vaunts this isopathy (æqualia æqualibus) as the only proper therapeutic rule, and sees nothing in the similia similibus but an indifferent substitute for it; ungratefully enough, as he is entirely indebted to the similia similibus for all his fame and fortune.