A new process has been lately invented by Dr. Pravaz, of Lyons, for coagulating the blood in the arteries, which he proposes to apply to the healing of aneurisms. The operation consists in injecting into the arteries a few drops of the perchloride of iron in its most concentrated state. The injection is effected by introducing a very fine trocar of gold or platina obliquely through the coats of the artery, to which a syringe is adapted. It is necessary to stop for the time the circulation in the artery. Of the three experimen+t noticed in the account made by the discover or to the French Academy of Sciences, the first was performed on a full grown sheep; the carotid artery having been exposed, the circulation was interrupted by pressure of the thumb and finger at two points an inch and a half distant, intercepting about ? spoonful of blood; a few drops of the styptic were then injected by the means above indicated. Immediately alter the operation an increased density of-the blood was perceptible to the touch; the rapid formation of the clot or co-agulum could be felt. Alter the lapse of four minutes the compression was removed; at the end of eight days the mass of curdled blood had not been driven from its position by the impulsion of the arterial blood. The two other experiments tried on horses confirmed the satisfactory conclusions drawn from the success of the first. Dr. Pravaz finds that about two drops of the perchloride of iron are requisite to the coagulation of a teaspoonful of blood. In applying the process to aneurisms, he would inject the percolorid e into the aneu-rismal cyst, after arresting the circulation by compression of the artery beyond the tumor, that is between it and the capillary vessels, in this way a compact clot of curdled blood may, he thinks, be found, acting like a cork to obstruct the artery and producing-the effect of a ligature.