Fig. 78.   Burn. Curve showing a reinfection of cutaneous origin upon a surface wound previously aseptic.

Fig. 78. - Burn. Curve showing a reinfection of cutaneous origin upon a surface wound previously aseptic.

Fig. 79.   Curve showing a prolonged reinfection of cutaneous origin.

Fig. 79. - Curve showing a prolonged reinfection of cutaneous origin.

Fig. 80.   Cicatrisation curve of the preceding wound. It is seen that the cicatrisation has slowed down considerably from Jan. 14 to Feb. 28, and that the slowing down coincides with the period of reinfection indicated by the preceding microbial curve (Fig. 79).

Fig. 80. - Cicatrisation curve of the preceding wound. It is seen that the cicatrisation has slowed down considerably from Jan. 14 to Feb. 28, and that the slowing down coincides with the period of reinfection indicated by the preceding microbial curve (Fig. 79).

Variations in quantity alone of microbes are to be considered, because the hypochlorite destroys microbes without distinction of species. Nevertheless, in the course of sterilisation, modifications in the aspect of the microbial flora may be seen. During the first two or three days, the smears contain rod-like bodies, which are often bacilli of Welch, and cocci (Fig. 69). Next, the cocci increase in number, while the rods completely disappear (Fig. 70). Now on the microscope field are to be seen nothing but isolated cocci, diplococci, clusters of staphylococci (Fig. 71), and chains of streptococci. Under the influence of the antiseptic the number of microbes diminishes (Figs. 72 and 73), and finally a few diplococci alone persist for a few days, then disappear completely.

(b) Suppurating Wounds. - In wounds which have reached the suppuration stage before the treatment was begun, the topography of infection is nearly uniform. Specimens taken from different regions indicate everywhere the presence of an almost equal number of microbes. Every morphological variety is represented. The microbes are sometimes isolated, sometimes in clusters, or again within the leucocytes. Sometimes they are so numerous that they form, under the microscope, an almost continuous layer. At the same time, the quantity of microbes contained in pus is extremely variable, according to the treatment which the injury has received. We have examined secretions from the wounds of casualties arriving in the Paris hospitals after having been treated in the field hospitals at the front by the usual means, such as ether or saline solution. All these wounds were suppurating, and the numbers of microbes contained in the secretions were sometimes so great that any attempt at counting was impossible. We have also examined wounds in a fair way to suppurate coming from hospitals (ambulances, Fr.) where sterilisation by means of Dakin's solution had been practised. As the technique had been imperfectly carried out, these wounds contained pus, but in this pus only some fifteen to twenty microbes were found, and sometimes only three or four per microscope field. Therefore there are considerable differences in the degree of infection, and no clinical sign enables one to distinguish a pus containing a large quantity of microbes from another sample of pus containing only a small number.

When a suppurating wound is being sterilised, the bacteriological curve declines almost immediately, and one of two phenomena may appear. In the first case the curve goes lower and lower. At the end of a few days the microbes disappear entirely, and sterilisation comes to pass as though a fresh wound were in question (Figs. 81, 82, and 83). The same evolution may be seen in surface wounds and in certain deep wounds of the soft parts. But sometimes, after one or several days of almost complete sterility, the pus yields anew a large quantity of microbes (Fig. 81), which are more often than not in clusters. These sharp ascents of the bacteriological curve are due to the circumstance that little pockets of pus, isolated from the principal cavity of the wound, have become opened and have scattered their contents over the newly sterilised walls. These reinfections are especially observed in very irregular wounds, and in compound fractures. Under the influence of instillation, the microbes may again disappear from the pus, either temporarily or permanently.

Fig. 81.   Left calf. Suppurating wound of soft parts, highly infected before arrival at hospital. Slow sterilisation at first, becoming more rapid towards the 15th day.

Fig. 81. - Left calf. Suppurating wound of soft parts, highly infected before arrival at hospital. Slow sterilisation at first, becoming more rapid towards the 15th day.

Fig. 82.   Very large, deep, and irregular wound in the posterior part of the thigh and the left obturator region; arrival at hospital in full tide of infection. Almost immediately suppuration disappeared completely. Diminution in the number of microbes became manifest 17 days after the commencement of treatment, and the immense wound was quite sterile and able to be closed 26 days after the entrance of the case into hospital.

Fig. 82. - Very large, deep, and irregular wound in the posterior part of the thigh and the left obturator region; arrival at hospital in full tide of infection. Almost immediately suppuration disappeared completely. Diminution in the number of microbes became manifest 17 days after the commencement of treatment, and the immense wound was quite sterile and able to be closed 26 days after the entrance of the case into hospital.