Man leaves his property, which is very ill of pleurisy over night, hopeless that the animal can survive till morning. On returning, however, to the stable early on the following day, to his surprise he beholds the horse actually looking better. The pain has evidently abated, if not altogether departed; the eye is more cheerful; the manner more encouraging. Having observed this, attention rests upon the flanks. The motion of these parts is greatly increased. They are now forcibly brought into action. The suspicion is awakened. The ear is applied to the chest. Near the breast bone, or low down, all is very quiet. A little higher up nothing can be heard; but rather past the middle of the ribs the sound of breathing is once more detected. Again and again is the experiment repeated, until the disappointed proprietor is forced to believe that which is against his hope. [Illustration: A HORSE DYING OF HYDROTHORAX.] Still clinging to chance, after conviction has gained possession of his mind, there is another trial he will make to render despair a certainty. He seeks some man--any one will do; and having found a loiterer, he returns with him to the stable. He places this individual upon one side of the horse, and tells the man to slap the side of the animal with the open palm, when the word "now" is spoken. This being arranged, the master goes to the opposite side. He puts his ear to the place where the silence ceased. Having assured himself the spot he has chosen is correct, he pronounces the monosyllable "now." Directly afterward a dull sound is heard, and a metallic ring or splashing noise is soon afterward audible. All now is confirmed, yet, "to make assurance doubly sure," the owner tries to take the pulse at the jaw. There is none to be felt! The hand is then placed near the chest, upon the left side and over the region of the heart. The sensation of a throb, coming through water, is perceptible. The last requirement is confirmed. The horse has =dropsy of the chest=, and the termination of the disorder is all but certain. [Illustration: MAKING THE PRIMARY INCISION FOR TAPPING THE CHEST.] [Illustration: A TROCAR WITH THE STILET UPON IT.] [Illustration: REMOVING THE FLUID IN HYDROTHORAX.] The first thing to be done, in these cases, is to draw off the liquid before it soddens the pleura and further distresses the already labored breathing. The manner of performing this operation is very simple, and the operation itself remarkably safe. A spot near the inferior margin of the chest being selected, a small portion of skin, between the eighth and ninth ribs, is pulled forward, and then a narrow slit with a sharp knife is made upon the place which the skin originally covered. A trocar, armed with a stilet, is then inserted into the opening, and so much force applied as suffices to propel it onward. The moment all resistance ceases, the trocar is within the cavity of the thorax. The stilet is then withdrawn, and the water usually flows forth.