OJ' 



NATURE 



[August 30, 191 7 



infected lining and also securer purchase for the serum 

 agar. The prepared tube is filled with antiseptic. And 

 then we can, after an interval, pour out the antiseptic, 

 fill in with nutrient broth or trypsinised serum, and 

 then incubate. Any microbes which have be^in left 

 alive in the lining will now grow out into colonies 

 which can be inspected through the walls of the tube. 

 Let me show you a set of typical results obtained 

 bv the test-procedures just described, using Dakin's 

 antiseptic, to-day perhaps the most popular of all anti- 

 septics. 



In tube I we have obtained, as you can see by these 

 subcultures, complete sterilisation. And it was ob- 

 tained after only momentary contact with the anti- 

 septic. In tube 2, where a lightly infected serum was 

 shaken up with, an equal bulk of the antiseptic and 

 then incubated, we have in our mixture of serum and 

 antiseptic a very vigorous growth of microbes. You 

 see the medium has become turbid, and there has been 

 an evolution of gas which has pushed up the plug of 

 congealed vaseline. In tube 3 — and here the antiseptic 

 stood fo^- four hours in the tube — we have in the barrel 

 a teeming multitude of microbes. And in tube 4, after 

 four hours' contact with the antiseptic, only that very 

 thin layer of the infected lining which coats the barrel 

 has been sterilised, in the depth of every spike the 

 bacterial colonies have come up quite thickly, and 

 only in immediate contact with the antiseptic have the 

 microbes been killed. And I here show you in a 

 companion tube which has been incubated twenty-four 

 hours longer that the microbes you have seen growing 

 in the deeper layers very sooi penetrate the sterilised 

 superficial layer, and grow out in the culture medium 

 in the barrel of the tube. 



When we find an antiseptic giving results quite 

 different from those here displayed it will then, for 

 the first time, become a rational policy to use, and 

 leave behind, an antiseptic in a wound with the view 

 of safeguarding the patient during lengthy transport. 



Suggestion that the bacterial infeciicn in the wound 

 can be kept down during transport by frequent re- 

 applications of an antiseptic. — In the earlier period of 

 the war the only method of re-applying an antiseptic 

 was that of taking down the dressing, syringing the 

 wound, and completely re-dressing. That was, espe- 

 cially in the case of deep wounds and compound frac- 

 tures, a very lengthy and painful procedure, and one 

 which was nearly impracticable in transport. For 

 that complete re-dressing there has now been substi- 

 tuted by Carrel a procedure for washing and refresh- 

 ing the surface of the wound through rubber tubes. 

 According to Carrel, Dakin's antiseptic should be em- 

 ployed, and this should be applied every two hours. 

 About the application of this in transport let me say 

 this : that it would, I think, be impracticable to carry 

 it out on a sufficiently large scale and sufficiently 

 systematically; and Dakin's antiseptic applied in an 

 unsvstematic manner gives exactly the same results as 

 simply keeping the wound wet. 



Suggestion that the set-hack in the wound during 

 transport could he prevented by dressing with hyper- 

 tonic salt solution. — ^The set-back in the wound with 

 its resulting tragedies could, I think, be avoided by 

 drawing out lymph in a continuous manner from the 

 tissues, and holding up the emigration of leucocytes. 

 The outflow of lymph would drive back and expel 

 invading microbes. It would also prevent the condi- 

 tions in the walls of the wound becoming unwholesome 

 to leucocytes. The continuous outpouring of lymph 

 would also effectively combat the corruption of the dis- 

 charges in the cavity of the wound. And, lastly, it 

 would prevent any drying up of the \\ ound. The effect 

 of holding up the emigration of leucocytes would be 

 to prevent the corruption of the wound discharges. 



NO. 2496, VOL. 99] 



You will remember that leucocytes, breaking down, 

 furnish the trypsin which corrupts the discharges. 



We have in a hypertonic solution the therapeutic 

 agent we require for these purposes. The proper way 

 of using it is to apply to the wound three or four 

 layers of lint thoroughly soaked in 5 per cent, salt 

 solution ; to impose upon these, as a reinforcement, 

 three or four more layers of lint thoroughly soaked in 

 saturated salt solution,* and then cover the whole 

 with jaconet, or other impermeable material. 



Remedial Treatment. 



I now pass from discussion of the method of pre- 

 venting the set-back that occurs in transport to the 

 discussion of its remedial treatment. The set-back will, I 

 as we have seen, have given us either a tryptic sup- | 

 purating wound or a dry slough-covered wound. In 

 each case the first item in treatment will be to get a 

 clean surface. For that it will, in the case of the 

 tryptic suppurating wound, suffice to wash away the 

 tryptic pus. In the case of the desiccated slough- 

 covered wound we must get rid of the sloughs. The 

 rational way to do that will be by cleansing digestion. 

 Such cleansing digestion can be obtained by treating 

 the wound with hypertonic salt solution. This will, 

 as we have already seen, break down leucocytes, set- 

 ting free trypsin, and then the free trypsin will rapidly, 

 and especially rapidly if we let the hypertonic salt 

 undergo dilution, amputate the dead from the living 

 tissues. Let us note that what we set out to do by 

 the use of hypertonic salt solution is only to achieve 

 more rapidly, and, as we shall see, with less risk 

 of infection, what putrefaction and the destruction of 

 leucocytes by microbes would, if we allowed things 

 to run their course, spontaneously effect. The second 

 item of treatment in each case will be to combat the 

 infection which has found a lodgment in the walls 

 of the wound cavity. To deal w ith this we require an 

 outpouring lymph stream, obtained by hypertonic salt 

 solution. 



If the train of reasoning I have laid before you is 

 correct, it will follow that hjpertonic salt solution is 

 the agent we require both for preventing the set-back 

 due to interruption of treatment in transport, and 

 also for remedial treatment. 



Experiments which Exhibit the Properties of 

 Hypertonic Salt Solution. 



You will very reasonably here expect me to produce 

 experiments to show that a hypertonic salt solution has 

 the virtues I ascribe to it. You will want to see for 

 yourselves that it attracts water, draws out fluid from 

 moist tissues, sets free trypsin from pus, and initiates 

 digestion. There is room here* only for the two 

 following experiments, which have reference to the 

 digestive cleansing of the wound. 



Experiment i. — I have here, as you see, two test- 

 tubes filled nearly to the top with egg-albumen. To 

 this was added 5 per cent, of carbolic acid, and the 

 albumen was tfien solidified by immersing the tubes in 

 boiling water. That done, I took two cotton-wool 

 plugs and steeped them in a pus to which I had added 

 5 per cent, of carbolic acid. I then inverted my tubes, 

 the one into a beaker containing 5 per cent, salt, 

 the other into a beaker containing physiological salt 

 solution. (Fig. 11, A and B.) To these also I added 

 ^ per cent, of carbolic acid. You will understand why 

 I chose carbolic acid as my antiseptic when I tell you 

 that it is one which does not destroy trypsin or 

 impede digestion. You see in the drawings made 



3 The saturated solution diluted with six parts of water will give us our 

 5 per cent. sa't. 



* The ex' eriments on the drawing action of strong salt solution were set 

 out in the fuller report of the lecture published in the Lancet of June 23. 



