1917] on The Treatment of War Wounds 85 



constituent albumens beint^: converted into pabulum for microbes^ 

 and immediately, as I think, light is projected upon our problem. 

 For once we envisage the facts in that way we are immediately 

 impelled to inquire whether the serum's power of inhibiting bacterial 

 growth may not be due to its power of neutralizing digestive 

 ferments, and whether the corruption of the lymph in the cavity of 

 the wound may not be due to a collapse of its defence against 

 proteolytic attack. 



That is a point which is very easily settled by direct experiment. 

 And let me now show you what happens when we add trypsin to a 

 serum which has been implanted with microbes. I have here two 

 tubes of a serum implanted two days ago with a minute quantity of 

 pus containing a variety of different microbes. To the one I added 

 trypsin, the quantity added being less than that required to neutralize 

 its antitryptic power. The other tube of the implanted serum served 

 as a control. After implantation both tubes were placed in the 

 incubator. And you see the difference. The trypsinized serum is- 

 turbid with microbic growth. That is, we have here exactly the same 

 result as that obtained in our pyo-sero-culture in those volumes of 

 serum which were corrupted by a heavy implantation of pus ; and 

 the same result also as was in the lymph leech experiment obtained 

 in the discharges in the wound cavity. Our control serum has, as 

 you see, remained almost perfectly clear. That is exactly the same 

 result as was obtained in our pyo-sero-culture in the distal end of 

 our tube, and again in our lymph leech experiment in the cavity of 

 the lymph leech. 



And the doctrine that the antitryptic power is the protector, and 

 trypsin the corrupter, of the blood fluids wins further support from 

 the following facts : 1. In every suppurating wound there is, as we 

 shall presently see, a source from which trypsin can be derived. 

 2. Blood fluids which inhibit microbic growth are strongly anti- 

 tryptic ; and blood fluids which we find teeming wdth microbes are 

 tryptic. 3. Examination of the blood shows that all wounded men 

 have a markedly increased antitryptic power, and heavily wounded 

 men on an average a three- or four-fold increased antitryptic power. 

 You saw in our pyo-sero-culture how by that microbic growth is 

 suppressed. You must not miss the meaning of that. It means that 

 the body when endangered takes steps to protect itself non-specifically 

 against all microbic infections of the blood fluids. 



The Leucocytes. 



I now pass on to consider the leucocytes and the part they play 

 in the destruction of microbes. You already know with respect to 

 leucocytes that they can emerge from the blood-vessels, burrowing 

 their way out through small pores in the capillary walls ; that they 



D 2 



