Fig. 14.   Influence of hypochlorite on an infected wound. Wound on the external aspect of the arm presenting an infection of cutaneous origin. A, control filter paper. B, filter paper soaked in Dakin's hypochlorite.

Fig. 14. - Influence of hypochlorite on an infected wound. Wound on the external aspect of the arm presenting an infection of cutaneous origin. A, control filter-paper. B, filter-paper soaked in Dakin's hypochlorite.

Fig. 15.   The same wound three days later. The lessening of the wound at the level of the control paper A is of the slightest. Beneath the filter paper B, the influence of the hypochlorite is manifest; the epithelial margin has greatly advanced, and the wound has lessened in a well marked manner.

Fig. 15. - The same wound three days later. The lessening of the wound at the level of the control paper A is of the slightest. Beneath the filter-paper B, the influence of the hypochlorite is manifest; the epithelial margin has greatly advanced, and the wound has lessened in a well-marked manner.

There was, therefore, a coincidence between the acceleration of cicatrisation and the application of Dakin's hypochlorite, under certain conditions, to the surface of the wound. We might, therefore, have been tempted to attribute to the hypochlorite of soda a stimulating action on cicatrisation. But as the wounds submitted to experiment were infected, and the bacteriological charts also showed a coincidence between the disappearance of the microbes and the acceleration of cicatrisation, it was probable that the cicatrising influence of the hypochlorite of soda was only apparent. In fact, the following experiments showed that hypochlorite of soda exercises no active influence on wounds already aseptic.

(d) Action of Hypochlorite upon the Cicatrisation of an Aseptic Wound. - In order to keep aseptic wounds sterile while their cicatrisation is being studied, hypochlorite of soda is applied to the surface during periods more or less long. But the rapidity of repair of these aseptic wounds, treated by means of hypochlorite, is not altered, and the curves do not show a more marked fall. This shows that the hypochlorite of soda has no cicatrising effect, and that the acceleration which it produced in the repair of infected wounds is due simply to the suppression of microbes. Under the actual conditions of the experiments, hypochlorite does not delay the repair of wounds moistened every two hours with 0.5 per cent. Dakin's solution. Or rather, any delay produced by the action of the hypochlorite is too slight to be evident.

We have endeavoured to study this possible retarding action of hypochlorite with the help of a more precise form of technique. On a large wound taking up the external aspect of the arm, repeated bacteriological examinations had shown the absence of microbes. The lower half of the wound was covered with a piece of gauze moistened every two hours with Dakin's solution, whilst the upper half was dressed with vaselin. At the end of four days a tracing of the wound was taken, and, on comparing it with the preceding tracing, it was seen that the epithelial border had progressed a little more rapidly under the vaselin than under the hypochlorite (Fig. 16).

At this time both the upper and lower parts of the wound were still aseptic. It would seem, therefore, that the hypochlorite of soda had slightly retarded the healing of an aseptic wound. But this retarding action was much feebler than the action of certain microbes, as the later history of the experiment showed. The wound was still being dressed with vaselin and hypochlorite. Bacteria soon appeared in the region dressed with vaselin, whilst that covered by hypochlorite remained sterile. A new tracing was taken, and, on comparing it with the preceding, it was found that the rapidity of healing had become greater under the hypochlorite than under the vaselin (Fig. 17). When physiological saline solution was used instead of vaselin, similar results were obtained.

These results were checked by experiments in which the rate of cicatrisation of wounds treated with hypochlorite was compared with that of wounds treated with other substances, in particular by distilled water, Wright's hypertonic solution, M. Delbet's chloride of magnesium, flavine, and chloramine.

Fig. 16.   Influence of hypochlorite on a sterile wound. The continuous outline represents the contour of a wound of the outer region of the arm which was sterile, Dec. 16. The half A was dressed with vaselin, and the half B with hypochlorite. The dotted line represents the state of the wound Dec. 20. It shows that the part A dressed with vaselin has healed a little more quickly than the part B dressed with hypochlorite.

Fig. 16. - Influence of hypochlorite on a sterile wound. The continuous outline represents the contour of a wound of the outer region of the arm which was sterile, Dec. 16. The half A was dressed with vaselin, and the half B with hypochlorite. The dotted line represents the state of the wound Dec. 20. It shows that the part A dressed with vaselin has healed a little more quickly than the part B dressed with hypochlorite.

FiG. 17.   Influence of hypochlorite on an infected wound. The preceding wound, under the influence of vaselin, became slightly reinfected. The dressings, however, were continued, the part A with vaselin, the part B with hypochlorite. The continuous outline represents the state of the wound Dec. 20. The dotted line represents the state of the wound Dec. 24. It is seen that the cicatrisation has taken place more rapidly in the part B, dressed with hypochlorite, than in the part A, dressed with vaselin.