The operation by _cauterization_ is highly recommended by English veterinarians. We believe, contrary to the statements of French authors, that it is not widely in use on this Continent. The objections urged against it are that the hemostatic effect upon the cord is less reliable than in the method by the clamps or the ligature; that there is more or less danger of cauterizing the surrounding parts by the effect of the radiant heat from the cautery; and that the swelling which follows the operation is always excessively great. Castration by the _clamps_ is the best known and most extensively practised. It is easy and quick in its performance; performs the most certain hemostasis upon the artery, and notwithstanding some slight objections, merits a preference over all others. The principal objection alleged against it is that it is attended with great pain to the suffering patient when the pressure of the instrument upon the soft tissues is first felt. This is a doubtful question, and if this excessive amount of pain really exists, it certainly cannot be of long continuance, merely on account of the effect produced by the clamps themselves. Of the various methods by _ligature_, that of the ligation of the cord with its envelopes is applicable to small animals only. That upon the cord alone is liable to be followed by hemorrhage, or by the excessive retraction of the cord into the abdominal cavity, drawing the ligature with it. That of the efferent canal, and of the cord by the subcutaneous mode are not admitted in general practice, while that of the artery alone has not been extensively performed on large animals, so far as we are informed, except by certain Massachusetts veterinarians. The castration by _double subcutaneous twisting_, when extensively applied to solipeds, will probably prove to be the safest mode of all, and least likely to be followed by complications. We are not informed as to the extent to which it has been practised in this country, even amongst ruminants. CHAPTER VI. CASTRATION OF FEMALES -- HISTORY -- INDICATIONS -- EFFECTS UPON THE ORGANISM AND SPECIAL FUNCTIONS -- ADVANTAGES IN COWS -- CONDITIONS FAVORABLE TO THE OPERATION -- ANATOMY -- MODUS OPERANDI -- BY THE FLANKS -- CHARLIER’S PROCESS -- INSTRUMENTS -- VARIOUS STEPS -- DIVISION OF THE VAGINA -- SEIZING THE OVARY -- TWISTING IT OFF -- COMPLICATIONS -- HEMORRHAGE -- PERITONITIS -- ABSCESS OF THE PELVIC CAVITY -- CONSTIPATION -- SUBCUTANEOUS EMPHYSEMA -- CASTRATION OF THE SMALL ANIMALS -- OF SWINE -- OF SLUTS -- OF FOWLS. As I have stated before, the revival of the operation of castration upon large females is due to a Louisiana farmer, Thomas Winn, who, in the year 1831, castrated several of his cows.