This method was modified by Gray, who used "salt packs "—i.e., tablets of sodium chloride placed within the layers of gauze used for packing the wound. In this case the salt is dissolved by the fluids of the wound, and a hypertonic solution is provided, which is less difficult to deal with owing to the smaller volume. This is a point of some importance, especially where patients have to be transferred from place to place.
2. The Carrel-Dakin method may be taken as typical of that applicable to the substances which depend on chlorine for their antiseptic power. here, ere, again, Gray's excision of wound surfaces is to be carried out, all pockets thoroughly opened up, and all foreign bodies sought for and removed. But here, instead of providing drainage, the wound is made to resemble a basin into every recess of which a fine rubber tube extends (Carrel's tube is a fine rubber tube, closed by a ligature at the end, and having a number of small lateral perforations). These tubes are con nected as in Wright's method with a reservoir above the bed level. Within the reservoir I )akin's solution is placed, and every 2 hours or so the nurse attending on the case opens a stopcock and allows a small quantity of the fluid to pass into the wound; excess of the solution and exuda tions escaping over the edge of the wound are absorbed by the dressings.
Eusol (prepared by mixing 12'5 grammes each of bleaching powder and boracic acid in a litre of water, allowing to stand overnight and filtering), as suggested by Lorrain-Smith, may be used in the same way as Dakin's solution. It is easy to prepare, and appears to be little if at all inferior
to the latter.
It is found that many of the wounds so treated can be closed by secondary suture in a few days, the actual time being dependent on the result of bacterial counts and on the infecting micro-organism. As a rule, where one microbe only per microscopic field is found, other circumstances being favourable, suture may be undertaken.
3. Rutherford Morrison has suggested another method of disinfecting the surfaces left after excision. This consists in smearing the surfaces with what is now everywhere known as Bipp, a paste made up of Bismuth Subnitrate (8 oz.), Iodoform (i6 oz.), and Liquid Paraffin (8 fl. oz.). The excess of the paste after lying in contact with the wound for a short time is wiped off and the sutures inserted.
4. Various other methods and materials have been used for the sterilisa tion of infected shell wounds, such as Flavine, Proflavine, Brilliant green, Alcohol 95 per cent. (Nogier). Ichthyol, Soap Solution (Ratynski), Borsal (a mixture of Boracic and Salicylic acids, Bismuth Carbonate in i-i,000 Perchloride of Mercury to make a paste (Moynihan), Urea, &c.
Those already described are typical of the others, and are the methods most generally used.