1917] 



on The Treatment of War Wounds 



37 



please and let it slowly diffuse down to the leucocytes. For the study 

 of the effect of bacterial infection, we can introduce microhes into 

 the blood before this is filled into the tube. Or as an alternatiye 

 blood can be filled into tubes whose walls have been wetted with a 

 microbic culture. Finally, we set our experiment going by placing 

 our emigration tubes in the incubator — that is, we supply to our 

 leucocytes the necessary warmth. And we can at any moment take 

 stock of what is occurring in our tubes by examining through the 



Fig. 4. — Drawing of four flattened capillary tubes — A, filled in 

 with blocd; B, a similar tube after centrifugalisation showing above 

 the " white " and below the " red clot '' ; G and D, similar tubes after 

 incubation. Leucocyfcic emigration is in each case visible to the naked 

 eye as an opaque white band occupying the lower portion of the 

 white clot. In D, where physiological salt solution had been imposed 

 upon the white clot, the band of emigration is much broader than in C. 



walls with the naked eye or with the low power of the microscope. 

 Also by a very simple technique we can extract the clot from the 

 tube and mount and colour it, so as to bring everything clearly into 

 view under the high powers of the microscope. 



Emigration of Leucocytes : Facts with Practical Application, 



I must limit myself to showing you in connexion with emigration 

 a few outstanding facts which have a practical application to the 

 treatment of wounds. Let me begin with the naked-eye appearances. 

 We have in Fig. i, C and D, emigration tubes containing centrifuged 

 blood which have been in the incubator for about eight hours. In 

 C — the control tube — we have centrifuged 1)lood to which no addition 

 has been made. In D some weak salt solution has been imposed upon 



