68 DEVELOPMENT OF ANTISEPSIS. 



limbs the region was enveloped in many layers of wadding suitably 

 affixed. The outer bandages were applied tightly, and if during 

 the next few days the degree of compression was considered 

 insufficient, or if the discharges penetrated the whole thickness of 

 the wadding, fresh bandaging was resorted to. At first the dressing 

 was left in position for twenty to twenty-five days, later it was 

 replaced at the end of twelve to fifteen days. As a rule on removing 

 the first dressing the wound was found to be granulating throughout. 

 With a second dressing left in position for eight to ten days cicatrisa- 

 tion was complete. 



To obtain primary union various modifications were made in this 

 method. Thus bleeding was more thoroughly checked, and the lips 

 of the wound carefully closed with deep sutures of some material 

 like catgut which would gradually disappear. Despite its many 

 advantages this dressing of cotton wool concealed the state of the 

 wound. The thermometer certainly gave indications of unfavourable 

 changes, but as considerable fever sometimes occurs even when 

 wounds are doing well, time was lost, and it was not infrequently 

 necessary to remove the dressings, thus exposing the patient to 

 danger. Further, although atmospheric germs could not enter the 

 wound through the layers of cotton wool, those already there or 

 introduced during operation were not destroyed, and frequently 

 multiplied with great rapidity. 



Compared with the older dressings that of cotton wool constituted 

 an immense stride in the surgical art, but, nevertheless, its use did 

 not become general. The greatest success was reserved for Lister's 

 dressing, which was more practical and also more certain in its 

 results. 



To prevent infection Lister sought to destroy all infectious 

 materials in and around the wound as well as in the neighbouring 

 air. Completing this process, he took care that the hands of the 

 surgeon and his assistants, the instruments, sponges, compresses, 

 and all materials used as dressings should be rendered thoroughly 

 aseptic. The wound having been cleansed of organisms was covered 

 with a material saturated with an antiseptic, and precautions taken 

 to prevent accumulation within it of serosity from the injured tissues. 

 Lister long preferred carbolic acid in solutions of 1 in 20 and 

 1 in 40. With the strong solution the instruments, sponges, and seat 

 of incision were disinfected, and once the operation was over, the 

 wound throughout. The weaker solution was used for disinfecting 

 the hands of the surgeon and his assistants, and for rinsing sponges 

 and instruments during operation. To prevent the wound being 



