Lime can be employed as a thick whitewash on pens, fences, yards, etc., the precaution being taken to see that it is newly burned, caustic and applied in sufficient amount. Lime that has been kept absorbs carbon dioxide and loses its disinfectant property. If ¼lb freshly made chloride of lime is added to each gallon of the caustic lime white wash the certainty of success is insured. Lime water has the advantage of being applicable to grassy surfaces, without proving hurtful to the vegetation. For buildings and yards it furnishes a ready means of estimating the thoroughness of the application. _Sulphuric acid_ (1:100 or 1¼ oz. to 1 gallon) makes a good disinfectant for buildings and yards. Like lime this can be used freely without fear of poisoning the animals. _Carbolic Acid_, 5 per cent, can be used with great safety. The Bureau of Animal Industry advises the combination of this with sulphuric acid, which adds greatly to its solubility. _Formalin_ may be employed, diluted one to forty of the solution (1 per cent of the gas) in buildings and on woodwork generally. It may also be applied in the form of gas by heating the solution in closed rooms. Like carbolic acid it is especially applicable to cars, boats, and other vehicles. _Corrosive Sublimate_ (1:500) makes a convenient and cheap disinfectant, with the drawback that it is poisonous, and destructive to metals. _Mercuric Iodide_ though more potent is also more expensive. Blue stone (2:100) and zinc chloride (10:100) are also effective but poisonous. The failure to _stamp out_ hog cholera in England and America has been largely chargeable on the appointment of laymen to do the work of the expert, and no less so on the attempt to deal with the disease in hogs in transit or in the market rather than in the farm where they have been raised or kept. Let the fat and stock markets be kept rigidly apart, together with the means of conveyance to and from these, and let no stock swine start for a market or destination without a certificate of the soundness of the locality from which they came, and the purity of the means of transit, and we shall have taken a long step toward the final extinction of the pest. State limits and rights stand in the way of successful work, but this can be partly met by a frontier supervision by national officials, and should be further, by a prompt and hearty coöperation of the sanitary officers of the two states involved. When it becomes possible to trace infecting hogs, back to the infected place in another commonwealth, and punish the offender who shipped them, we shall be within sight of a satisfactory control or extinction of hog cholera.