(c) Action of Hypochlorite upon the Cicatrisation of an Infected Wound. - Many experiments were made upon surface-wounds whose curves of cicatrisation were known, and of which the bacteriological condition was recorded. These wounds generally showed from five to twenty microbes per microscope field, and the observed curve of cicatrisation showed a slighter fall than the calculated curve (Figs. 10 and 11). A perforated tube was applied to the surface of the wound and Dakin's solution instilled every two hours. In all cases without exception cicatrisation was hastened and the curve of cicatrisation dropped (Figs. 12 and 13). The speed of the repair often increased in such a manner that the observed curve rejoined the calculated curve, but without ever having a more rapid fall than that of an aseptic wound. Therefore there was no accelerating action due to the hypochlorite. The rapidity of the cicatrisation in presence of Dakin's solution was sometimes considerable. A wound of the leg, wide and of long standing, communicating with an unsterilised bone injury, yielding a great number of microbes from its surface, was healing very slowly. The cicatrisation curve was dropping only slightly. This wound had a surface of 75 square centimetres. As soon as it was treated with Dakin's solution the curve fell sharply. In four days the wound lessened by 28 square centimetres, and during the following days the repair continued at approximately the same rate. It should be noticed that the sterilisation chart showed at the same time a considerable lessening in the number of microbes. The same phenomenon was observed in all wounds uniformly infected, and cicatrising with a known rapidity, which were treated with Dakin's solution. With the exception of those containing a foreign body, all wounds responded to the treatment. To remove the foreign body was to ensure that the wound would follow the general rule.

Fig. 12.   Influence of the sterilisation of a wound on the progress of cicatrisation. . The cicatrisation curve shows how a sluggish looking and highly infected wound steadily enlarged from 6 to 15 square centimetres from the 14th to the 29th of Nov. It was sterilised on the 29th of Nov. Instantly cicatrisation commenced and its course followed a geometric curve.

Fig. 12. - Influence of the sterilisation of a wound on the progress of cicatrisation. . The cicatrisation curve shows how a sluggish-looking and highly infected wound steadily enlarged from 6 to 15 square centimetres from the 14th to the 29th of Nov. It was sterilised on the 29th of Nov. Instantly cicatrisation commenced and its course followed a geometric curve.

Fig. 13.   Bacteriological curve of the preceding wound. The graph shows that, under the influence of Dakin's hypochlorite, the number of microbes, at first infinite, rapidly dropped. The coincidence between the date of sterilisation of the wound and that of the beginning of normal cicatrisation should be noticed.

Fig. 13. - Bacteriological curve of the preceding wound. The graph shows that, under the influence of Dakin's hypochlorite, the number of microbes, at first infinite, rapidly dropped. The coincidence between the date of sterilisation of the wound and that of the beginning of normal cicatrisation should be noticed.

Upon deep wounds few observations were made. However, some experiments were carried out of the following type. A collection of pus had formed on the antero-external aspect of the leg of a man with arthritis of the knee. This collection, which was accompanied by a rise of temperature, was opened at its upper part and the pus evacuated. The next day the wound was washed with Ringer's solution, and its capacity measured 26 c.c. The wound was irrigated with hypochlorite. Twenty-four hours later the suppuration had disappeared. In the bottom of the cavity a little liquid was found, syrupy, yellow, transparent. The secretions contained only one coccus per microscope field. The volume of the cavity now was not more than 7 c.c. Forty-eight hours later it was reduced to 2 c.c, and the wound was completely sterile. Then it closed. In short, an abscess cavity of 26 c.c. was sterilised and completely closed in four days. Similar experiments were made, and yielded results comparable. But the diminution in volume of deep wounds comes about in a more irregular manner than the cicatrisation of surface-wounds. It was upon the latter, therefore, that the majority of the experiments were made.

In order to obtain more strictly controlled observations, experiments were made on different parts of the same wound. For example, two strips of filter-paper were applied at the upper and lower extremities of a wound of the external aspect of the arm, with fracture. Each strip stretched from one margin of the wound to the other, over the granulations, after the manner of a bridge. The previous bacteriological examination had shown that the whole surface of the wound was uniformly infected. The filter-paper at the lower part of the wound received an instillation of Dakin's hypochlorite every two hours, whilst the filter-paper at the upper part was not moistened (Fig. 14 and Fig. 15).

At the end of three days it was obvious that the edges of the wound were not altered in the upper region, but that, in the lower part of the wound, cicatrisation had progressed much more quickly. The parts covered by filter-paper moistened with hypochlorite showed granulations softer and redder than those in the other regions of the wound. The change in the appearance of the granulations followed a transverse line very closely corresponding to the upper border of the filter-paper. A marked acceleration of the cicatrisation, therefore, had taken place in the region treated by Dakin's solution (Fig. 15). At the same time the bacteriological examination showed that the microbial flora were not modified over the untreated part of the surface of the wound, whilst in the region covered by filter-paper soaked in hypochlorite, microbes had completely disappeared. In other experiments, where a part of the infected wound was dressed with vaselin, and another part with hypochlorite of soda, there was to be observed, in similar fashion, acceleration of cicatrisation in the region treated by hypochlorite.