Chemical sterilisation of a wound is brought about by instillation, continuous or intermittent, of an antiseptic liquid, by means of small rubber tubes, into all the recesses of a wound. As the quantity of liquid used is very small, it is not necessary to employ drainage tubes or to arrange for reception of an overflow. The liquid which has moistened the tissues is absorbed by the dressing and evaporates. Instillation thus practised permits of the continual renewal of the liquid over every portion of the wound. This procedure differs from the old "irrigation," in that it is much simpler, and in that the liquid is carried directly to the deepest diverticula of the wound.

I. Conducting Tubes And Reservoirs

A. The Conducting Or "Instillation" Tubes

The conducting tubes are of red rubber. The rubber wall of the tube has a thickness of 1 mm., and the interior diameter is 4 mm. They are thus resistant and flexible. These qualities allow of their penetration to every irregularity of the wound, and of their adequate resistance to the pressure of muscles and dressings. Three kinds of tubes are used.

1st. Tubes perforated with Small Holes. - The length of these tubes varies from 30 to 40 cm. (roughly 12 to 16 inches). Some of them are closed at one end by a ligature, and pierced by small holes over a length of from 5 to 20 cm.1 from the closed extremity (Fig. 35). The holes number about eight to each 5-cm. section. Their diameter is about half a mm.2 The holes are made by means of an ordinary punch. These tubes are the most used. Four different categories are in use, according as the holes are perforated over a length of 5, 10, 15, or 20 cm. Other tubes are left open at each end and pierced with holes only in their middle third (Fig. 18, E). Liquid enters by each end.

Fig. 35.   Conducting or instillation tubes, rubber, with multiple holes, closed at one end.

Fig. 35. - Conducting or "instillation" tubes, rubber, with multiple holes, closed at one end.

A. Tube 30 cm. long, pierced over a length of 5 cm.

B. Tube 30 cm. long, pierced over a length of 10 cm.

C. Tube 40 cm. long, pierced for a length of 15 cm.

D. Tube 40 cm. long, pierced for a length of 20 cm.

E. Tube open at both ends, and pierced over a length of 20 cm. in its median portion (10 cm. = about 4 inches).

1 Say 2 to 8 inches.

2 1/50th of an inch.

2nd. Tubes with a Single Opening. - These are of a length of from 25 to 30 cm.1 and the ends are open (Fig. 36). At half a centimetre from one end a large lateral opening is made. This lateral orifice is intended to permit the egress of liquid should the terminal orifice become blocked.

Fig. 36.   Conducting or instillation tube with terminal opening. Tube of about 30 cm. long, open at both ends, with a lateral opening near one end.

Fig. 36. - Conducting or "instillation" tube with terminal opening. Tube of about 30 cm. long, open at both ends, with a lateral opening near one end.

3rd. Tubes perforated with Small Holes and covered with Absorbent Fabric. - These tubes are closed at one extremity and pierced with small holes over a variable length. The section pierced with little holes is covered with a sheath of fabric similar to the material of which bath towels are made (Fig. 37). This sheath is firmly stitched to the tube. It is intended to distribute the liquid over the whole surface of the tube as it escapes from the holes. It is important that the cover should be so firmly fixed by a stitch to the rubber tube that it cannot remain behind in the recesses of the wound when the tube is withdrawn.

Fig. 37.   Conducting or instillation tube covered with a sheath of bath towelling (tissu eponge).

Fig. 37. - Conducting or "instillation" tube covered with a sheath of bath-towelling (tissu eponge).

These tubes are of uniform length. They can easily be lengthened to any extent by means of pieces of rubber tube of the same calibre and "unions"of pieces of glass tube (Fig. 39, C) of a calibre of 4 mm. and a length of 2.5 cm.

1 Say 9 to 12 inches.

B. The Distributing Tubes

The tubes pierced with holes are grouped into sets of two, three, or four by means of appropriate branched tubes. Two types of branched tubes are employed (Fig. 38).

Fig. 38.   Glass distributing tubes (Gentile).

Fig. 38. - Glass distributing tubes (Gentile).

A. Tube with one branch.

B. Tube with two branches.

C. Tube with three branches.

D. Tube with four branches.

Fig. 39.  Glass connecting tubes, unions.

Fig. 39. -Glass connecting tubes," unions."

A. Cylindrical tube of a length of 4 to 5 cm. and an interior diameter of 7 mm.

B. Y-tube with an interior diameter of 7 mm. These tubes unite the ends of rubber irrigating tubes.

C. Cylindrical tube of a length of 3 cm. and an interior diameter of 4 mm. This tube serves to join-up two small conducting tubes, when it is necessary to add to the length of one of these tubes.

1st. The Y-shaped tube is composed of a main stem about 2 cm. long with a calibre of 7 mm., and of two limbs or branches of equal length, about 2 cm., whose interior calibre varies between 3 and 4 mm. (Fig. 38, B).

Upon the two branches are fitted either two simple instillation tubes, or the two extremities of a tube perforated with holes in its middle portion.

2nd. The distributor with four branches is composed of a glass tube closed at one end, 6 or 7 cm. long, and of a calibre of 7 mm. (Fig. 38, D). From one side of this tube project at right angles four smaller tubes, each of a length of 2 cm. and an interior calibre of 3 to 4 mm. Thus it has the look of a comb. In the same manner one may have three branches (Fig. 38, C), or five or six.

3rd. Small glass connecting tubes or "unions" must also be at hand to join together the rubber tubes of large or small calibre, or to unite a rubber tube of small calibre to one of large. The first are cylindrical glass tubes 2 to 3 cm. long, and of a calibre of 4 and of 7 mm. (Fig. 39, A and C). The others are conical glass tubes of the same length, presenting at one extremity an interior diameter of 3 to 4 mm., and at the other extremity an interior diameter of 7 mm. (Fig. 38, A). Tubes of Y-shape are also in use, of 7 mm. calibre, for joining up irrigating tubes (Fig. 39, B).