The sanitary movement has shown that more people die every year from avoidable causes than would satisfy the yawning gulf of a severe epidemic, or the most destructive battle. In a crowded community, many events are daily impressing on the heads of families, besides the expedience of avoiding unnecessary expenses, that long illnesses are long evils; that their dearest connections are sometimes prematurely broken; and that parts are not unfrequently found diseased which are not suspected to be so during life. The thought will sometimes occur whether this may have been always consequent on the _difficulty_ of the subject, or whether it may not have been sometimes the result of _too hasty or too restricted_ an inquiry; that not only (as the Spanish tutor told his royal pupil of kings) do patients die "sometimes," but very frequently. These and other circumstances have induced many of the public to inquire into the reason of their faith in us; and to ask how it happens that, whilst all other sciences are popularized and progressing, there should be any thing so recondite in the laws governing our own bodies as to be accessible only to comparatively few; especially as they have begun to perceive that their interests, in knowing such laws, is of the greatest possible importance. Amongst various attempts to better this condition of things, the imagination of men has been very active. Too proud to obey the guidance, or too impatient to await the fruition, of those cautious rules which the intellect has imposed on the one hand, and which have been so signally rewarded (whenever observed) on the other, imagination has set forth on airy wing, and brought home curiosities which she called science, and observations which, because they contained _some_ of that truth of which even fancies are seldom entirely deprived, blinded her to the perception of a much larger portion of error. Two of these curiosities have made considerable noise, have been not a little damaging to the pecuniary interests of the medical profession, and have been proportionately species of El Dorados to the followers of them. We allude to the so-called Homœopathy and Hydropathy. Homœopathy proceeds on an axiom that diseases are cured by remedies which excite an action similar to that of the disease itself; "_Similia similibus curantur_." Our objection to this dogma is twofold, and, in the few hints we are giving, we wish them not to be confounded. 1st. It is _not_ proven. 2nd. It is _not_ true. Take the so-called fever. The immediate and most frequent causes of fever are bad air, unwholesome food, mental inquietude, derangement of the digestive organs, severe injuries. Now it is notorious that very important agents in the cure of all fevers are good air, carefully exact diet or temporary abstinence, and correction of disordered functions, with utmost repose of mind and body, and so forth.