302 THE AMERICAN MONTHLY [Oct., 



Such, then, are the changes which cliaracterize the com- 

 meucemeut of inflammation and its progress as seen under 

 the microscope. 



With the thought in my mind that "we learn new 

 things only by more carefully and patiently observing 

 old ones," I have spent nearly all of three months (July, 

 August and September) in studying, beneath the micro- 

 scope, the following phenomena of commencing inflamma- 

 tion — dilatation of the capillaries, slowing of the blood 

 stream, and the escape of the leucocytes or white blood 

 corpuscles from the blood vessels into the surrounding 

 tissues. 



I made these observations with but little hope of dis- 

 covering any new facts where such observers as Colm- 

 heim. Lister, Strieker, Bottcher and others had so care- 

 fully and scientifically worked, but simply to convince 

 my own mind of the truth of their revelations, and to de- 

 cide, if possible, to my own satisfaction, certain points, 

 regarding the diapedesis of the leucocytes, which are 

 still in dispute. It will hardly be necessary for me to 

 say that my results confirmed their observations, and in 

 one or two points, my observations, although differing 

 somewhat from theirs, have cleared up, to my own mind, 

 disputed questions, the principal of which is that regard- 

 ing the part taken by the leucocyte in its passage through 

 the vessel wall. 



I put forward no new theories, but simply state, in as 

 plain a manner as possible that which I have seen only, 

 leaving to others the task of working out the theory 

 which will accord w^ith the facts. 



My observations have been made upon the foot-webs 

 and mesenteries of ten frogs, and extended over a period 

 of about three months, as before stated, I have not at- 

 tempted to write out a description of each individual case 

 for that would be but repetition, but simply have drawn 

 general deductions from them all. 



