The most rapid and powerful of the disinfectants is the solution of the bichloride of mercury (corrosive sublimate). The solution most commonly used is of the strength of fifteen grains to the quart. It can be applied directly to floors, beds, walls, sinks, drains, vessels, &c. For clothing use a solution of common salt and sulphate of zinc, two ounces of the salt and four ounces of the sulphate to a gallon of hot water; soak the clothes in this and then boil them in water with borax, or soap or soda. When a disease is known to be very contagious and dangerous, especial care is necessary to avoid contact on the part of patients and nurses with outsiders. All superfluous things must be taken out of the room before the patient is put into it, and care will be necessary continually to make the quarantine effectual. Every article carried out of the sick room must be disinfected; a set of dishes should be kept for the patient’s exclusive use, washed only by the nurse; the bedding, clothing, &c., must be washed by the nurses themselves, after being soaked in a disinfecting solution; dressings and other cloths, such as old cloths used for handkerchiefs, may be burned; all excrementitious and vomited matter must be disinfected; the broom that is used to sweep the room must not be used elsewhere; no current of air must be permitted to pass from the sick room to the rest of the house; and it is well also to hang about the room cloths wet with some disinfectant solution; hang over the doorway a sheet similarly disinfected; and the nurse should cover her head with a close cap. Lest the confinement and isolation make the nurse sick she must take care of her own health. Two nurses should be employed for every such case, so that neither may be obliged to sleep in the same room with the patient, and each should change her clothes and go out of doors for a time every day and take a brisk walk in the open air. The ventilation is of especial importance in contagious diseases, as no disinfection can render the air entirely pure. To prevent the infectious particles that are thrown off the skin in cases like small pox and scarlet fever, from polluting the air of the room, the clothes should be frequently changed, and the patient’s body be washed and anointed with some ointment. Charcoal placed about the room in shallow vessels does some good by means of its property of absorbing gas; and solutions of carbolic acid, chloride of lime, soda, and zinc are germicides, but the chief use of the carbolic acid family is where suppuration is going on, to prevent the spread of septic infection. It is also a means of disinfection perhaps, if the spray is used in malarial disease. Condy’s fluid and sulphate of iron are used as antiseptics, but these stain clothing. Chlorine should not be used with sulphuric acid, or carbolic acid.