AS A SURGICAL DRESSING 295 



cool in mass, that it must be opened up while warm, and upon the way in which 

 this is done by the manufacturer much depends as to the quantity of the anti- 

 septic present in the gauze. In the next place, a volatile antiseptic, such as 

 either carbohc acid or eucalyptus, has the disadvantage that it n-quires careful 

 treatment by the surgeon himself. The material containing it must be kept 

 in well-closed metallic vessels ; otherwise evaporation soon impairs its qualities. 

 And in the third place, there is this disadvantage attending all volatile anti- 

 septics, that the longer the dressing is kept upon the body the less efficacious 

 does it become ; and who is to say when the time arrives when it has become 

 so inefficacious that it is necessary to remove it ? I have been accustomed to 

 regard a week as the limit of the time during which a carbolic-acid gauze dressing 

 may be regarded as effectual ; but, beyond the fact that with this period our 

 results were on the whole satisfactory, we had not what we may call precise 

 grounds to go upon. In that respect, a volatile antiseptic must alwavs be at 

 a disadvantage, as compared with a non-volatile one, which will be just as 

 effixacious at the end of a month, or six weeks, as it is when first applied, provided 

 it is not soaked with the discharge. 



Salicylic acid is a non-volatile antiseptic ; but salicylic acid, as I ascer- 

 tained from experiments, several years ago, is very far from being as powerful 

 in antiseptic qualities as carbolic acid, and therefore I have never ventured to 

 use it for serious cases. Iodoform, while volatile, is very slowly volatile, and, 

 at the same time, so little soluble in the discharges, that in these points of view 

 it seems an admirable antiseptic ; but iodoform is by no means a potent agent 

 in its action on micro-organisms. I ascertained, some years ago, for example, 

 that, taking a 10 per cent, iodoform wool, the strongest used, and soaking this 

 with milk, the lactic fermentation was only a short time retarded, and in the 

 course of a few days not only the Bacterium ladis, but multitudes of other 

 kinds of bacteria were seen, in abundance, in the milk. Again, uncontaminated 

 urine being made to soak such a piece of wool, and then inoculated with putrefy- 

 ing urine, I found that the ammoniacal fermentation was only a short time 

 retarded by the iodoform. Hence I was not surprised to learn that, in the 

 practice of Schede of Hamburg, and others, it had been found that erysipelas 

 occurred under the iodoform dressings. It is remarkable that iodoform has 

 such an effect as it has in preventing putrefaction, but it is by no means 

 a powerful germicide. 



But there is another non-volatile antiseptic, corrosive sublimate, to which 

 attention has been more especially directed of late years b\' Dr. Koch ; and 

 here I may be permitted to give my tribute of i^raise to the admirably conceived 

 and conclusive experiments which he has performed \\\)0\\ this subject. Koch 



