and several which, while they are useful, are not so common. Probably the most reliable and popular amongst them may be enumerated as follows:-heat, chlorine, sulphurous acid, nitrous acid, carbolic acid, Condy's fluid, chloralum, ferrous sulphate, chloride of zinc, chloride of lime, M'Dougall's and Calvert's powders, and charcoal.

SECTION III-PRACTICAL DISINFECTION.

1. Hygiene of the Sick-room. In all cases of highly-infectious disease, the first duty to be attended to is the enforcement of a strict domestic quarantine by isolation of the patient whenever it is possible; the next point is to make certain that the room is well lighted and sufficiently ventilated by means of open windows, and fires if necessary; and the third point is to require the instant removal of all extraneous furniture, such as carpets, curtains, and the like. The attendant on the patient should receive strict and precise injunctions, not only with regard to the nursing of the patient, but also with regard to the maintenance of the utmost cleanliness in the room; the disinfection of excreta, slops, soiled linen, etc., and their immediate removal afterwards; and other points of detail depending upon the special nature of the disease and the circumstances of the patient.

Although aerial disinfectants are regarded by some as of doubtful efficacy in the sick-room, they are deemed to be useful or expedient by many; and, when properly selected and managed, it may be said, at all events, that they do not do any harm, if they are not productive of much good. The great danger is, that when employed

without due precaution, they may only serve to disguise the signs of insufficient ventilation, and in this way conduce to inattention as regards this most essential point. If they are employed-and many believe that their use is imperative in some diseases-they should not be irritating to the patient. Chlorine gas slowly evolved, or carbolic acid vapour, are the agents which commend themselves to most. The vaporiser introduced by Savory and Moore, or Siegle's spray producer, is each an excellent instrument for distributing the carbolic acid vapour, or it may be distributed to the desired extent by placing a little of the acid in wet sand in flat dishes, or by using the powder as a cleansing agent in scrubbing out the floor daily. Hanging rags steeped in disinfectant solutions about the room is not to be commended, but a sheet moistened with a strong solution of chloralum, carbolic acid, or Condy's fluid, and suspended outside the door of the room, is very necessary to complete the isolation of the patient. The infected clothing, etc., should be received into a tub containing chloralum or carbolic acid, and the ejecta, etc., should be instantly covered with Burnett's solution, copperas, chloralum, or carbolic acid. Care must also be taken, in using different disinfectants, that they do not counteract each other; for example, carbolic acid decomposes Condy's fluid. Further, as has already been pointed out, the inunction of the body of the patient, in certain of the exanthematous infectious diseases, with camphorated oil, or a weak solution of glycerine and carbolic acid, followed by disinfecting baths during convalescence, appears to be attended with very good results.

2. Disinfection of Empty Rooms and Uninhabited Places. After a case of infectious disease, the room

should be thoroughly cleansed and disinfected. The furniture should be washed with a strong solution of chloralum (three or four ounces to the gallon of water), or with carbolic acid soap, and the room, as far as possible, emptied. Afterwards the floor and wood-work should also be thoroughly washed with carbolic acid soap, and the paper, first moistened with chloralum or carbolic acid solution, should be removed. Then, after closing doors, windows, and other openings, chlorine, sulphurous acid, or nitrous acid gas, should be generated in large quantities in the manner already described, and the room kept closed for several hours. After this, the door and windows should be thrown open, and in a few days the ceiling should be washed with quick lime and whitened, and the walls re-papered.

3. Disinfection of Clothing, Bedding, etc.-Any material of this description which cannot be injured by being washed, should be steeped in a solution of chloralum or carbolic acid, and boiled. If Condy's fluid be used, the material should merely be immersed, and afterwards rinsed out in cold water, otherwise the solution will stain. In all cases, however, when it can be carried out, the clothing, bedding, etc., are best disinfected by being exposed for an hour at least to a dry heat of about 240° or 250° Fahr., and for this purpose every town of any dimensions should be provided with a hot-air disinfecting chamber for public use. Such a chamber is built of brick, and is heated by a coil of hot-air pipes lying underneath a perforated grating, and communicating with a furnace which opens outside.

The hair of infected mattresses should be teased out, exposed to the air, and, whenever possible, should be disinfected in the hot-air chamber. Rags and other

articles which can be spared should be destroyed by fire. When clothing cannot be disinfected by heat, Dr. Ransome has proposed that the different articles should be placed, layer on layer, in a box, with hot sand or bricks placed at the bottom, and sprinkled over with carbolic acid.

4. Disinfection of Water-Closets, Urinals, Sinks, etc.— In any district where an epidemic prevails or is threatening, disinfection of all water-closets, etc., should be carried on systematically, either with solutions of chloralum, carbolic acid, copperas, or Burnett's fluid. Cooper's salts might be used for the streets, lanes, and open courts. Any manure heaps or other accumulations of filth, which it is inexpedient to disturb or impossible to remove, should be covered with powdered vegetable charcoal to the depth of two or three inches, or with a layer of fresh dry earth, or with freshly-burnt lime, if charcoal cannot be obtained. Cess-pits and middenheaps may be disinfected with solutions of copperas (3 lbs. to the gallon of water), or with chloralum (1 lb. to the gallon of water). It need hardly be said, however, that in a town or district well looked after by the sanitary authorities, no such filth-accumulations would be allowed to take place at any time.

5. Disinfection of the Dead Body.—When a patient dies of a highly infectious disease, such as smallpox or scarlatina maligna, the body should be washed with a very strong solution of carbolic acid or chloralum, and placed in the coffin as soon as possible, disinfectants being again freely used, and the lid screwed down. The burial should take place without delay; or in crowded districts, and in towns where a mortuary is provided, the dead body should be at once removed

thither. The linen worn by the patient at death, if not buried with the body, should be destroyed by fire. It may be urged that many of these directions are needlessly minute, and that, in fact, they cannot possibly be carried out in perhaps the great majority of cases. In answer to such objections, let it be said, once and for all, that no labour is wasted which aims at preventing the spread of disease, even though it be often attended with failure; and that, however limited be the means or opportunity of carrying out preventive or precautionary measures, such means and such opportunity should always be used, so as to be productive of the best possible results under the circumstances.