Now comes the sad inquiry, what is the cause of pleurisy? All kinds of things may excite it; but those things which lead to so much suffering in an inoffensive animal, are under the control of man. Over-exertion, being driven or ridden far and fast, the spirit being stimulated, and the energy promoted by potent drinks; for men will give the contents of the public-house to the horse when a wager is at stake, and will lash, while the limbs can move, to win any pitiful bet,--these circumstances not unfrequently provoke pleurisy. Injuries received externally not unseldom start up internal inflammation. Hurts calculated to lead to so serious an evil, together with broken ribs, will not be surprising to those who have seen the unseemly instruments which man will, in his rage, seize upon to strike the animal with. Colds, aggravated by change of temperature, as waiting long in the rain and being flurried home afterward; inattention in feeding, thus generating a plethora, is apt to disorder any internal organ, and many other such like causes will generate the disease. And what right has man to inflict so much agony upon any life intrusted to his care? What right has humanity to complain of tyranny in its superiors, when the human race can neglect and entail such anguish upon the beings beneath them? The greed of gain or the pride of winning are the first motives assigned as the promoters of this terrible affliction; next come the gratifications of passion; then follows carelessness for another's welfare, etc. Which of these several causes is worth the torture of a living body? such torture, too, as the rack cannot equal, and human malice is happily forbidden to rival! A little self-restraint instilled by a better plan of education, a little more humanity enforced by the teachers of religion, to instruct that man should not view himself as the owner of the earth which he temporarily inhabits; that man should not consider himself the proprietor of the lives which share the globe with him; that man should be actuated by genuine CHRISTIAN LOVE toward all animated nature, feeling kindly for the lives akin to his own, and acknowledging, as fellow-sojourners, the creatures by which he is surrounded,--then, how much affliction might be eradicated from that which wickedness alone renders a "vale of tears!" HYDROTHORAX. This is the consequence of the latter stage of pleurisy; or rather, to speak with caution, we fear it is often the result of the severe treatment adopted to dispel that malady.