Castration is one of the most simple operations, requiring nothing more than a sharp knife, a steady hand and a little experience. The most suitable age, I consider to be from five to nine months. For this operation, the animal should be made perfectly secure, by one person holding his head, and a second the legs, whilst the hands of the operator must be perfectly free. If the dog's head be put into a bag, or be otherwise covered, he will be far less restive, or perhaps wholly unconscious of any danger. For all painful operations, a dog should be blinded ; it will detract greatly from his nervous restlessness and materially facilitate the process. The skin at the base of the testicle should be firmly held between the thumb and finger of the left hand, so as to present a fair tightened surface; then cut through the skin just deep enough to expose it to view. Whilst you still hold perfectly fast with the left hand, draw out the testicle, string and all with the right. Should it be difficult to draw out, the knife may be passed round it, to facilitate the extraction, but if the operation be performed at an early age, this will seldom be requisite, as the pressure of the thumb and finger will suffice to force the testicle out so as to present a fair hold for the right hand. Should the string not draw out, it may be cut off; of course each must be taken out separately ; the same means used in extracting the first, applies also in the second. The operation should not be performed either during very warm or cold weather, unless the animal can be kept in a somewhat moderate degree of warmth, for at least a couple of weeks. No after-application is required, other than washing the parts, with strong salt and water, immediately after the operation, and a little lard or goose-grease, to soothe the irritation. The dog should be kept cool, quiet and cheerful ; his food should not be gross, and he may require a little cooling physic. He should be exposed to no extremes of either heat or cold, be allowed very little exercise and be kept in a perfectly clean place, that no dirt may enter the sore. The changes produced by this operation differ in different subjects ; as a general thing, its results are fat and a lazy independence, and of course in all cases a perfect indifference to the charms of the other sex. I am inclined to believe that if these altered subjects were not allowed to get too fat, they probably would retain more of their natural vigor. I am far from believing that it detracts either from their sagacity or intelligence. I have seen several cases, where it has added to their pluck and daring. These may be quoted as exceptions. They are decidedly less inclined to roving, are more cleanly in their habits and the more easily recovered, if lost.