Dissolution is the reverse of this. We have, then, to see if inflammation corresponds to a definition running thus: Dissolution is a disintegration of matter and concomitant absorption of motion, during which the matter passes from a definite, coherent heterogeneity to an indefinite, incoherent homogeneity, and during which the retained motion undergoes a parallel transformation.
The first thing which our definition asserts is, that inflammation is a disintegration of matter. This proposition needs little defense. Do we not find that inflamed parts are always softened, and that when the process is severe and continued they become liquefied, converted into pus? Inflammation clearly is a process which tends to the disintegration of matter. We learn, next, that the disintegration of matter is accompanied with concomitant absorption of motion. This, on consideration, will be found equally true, although, perhaps, not so obvious. In the process of evolution the motion of units (molecular motion) becomes converted into the motion of aggregates (molar motion); and in dissolution the reverse takes place. The latter we shall find hold good of inflammation. An inflamed part is not only softened—which means that its component molecules move more readily upon one another—but it is swollen. The particles previously integrated into a solid mass, occupying a small space, have most of them moved farther away from one another, and now occupy a comparatively great space. Besides this, it is hotter than natural, and heat is a mode of motion. There is thus an increase of molecular motion. With this, the functional activity of the part which, from our present point of view, is its motion as an aggregate (for all force is a mode of motion), is lessened. To take the most literal illustration: an inflamed muscle can not contract with the force of a healthy one. Seeing, then, that there is an increase of molecular motion in an inflamed part, we might be content with pointing out that this motion must have been obtained from somewhere. But we may go further. There is one remedy, the potency of which, in checking inflammatory change, can not be gainsaid. It can not everywhere be efficiently applied, and it is not always decidedly for the patient's benefit that inflammation should be too rudely cut short; but, when circumstances admit of cold being brought into play, there is no doubt that it will arrest or suspend inflammatory change. We find throughout the universe that cold everywhere arrests molecular motion. It makes fluids into solids, vapors into fluids; checks chemical as well as vital change. The inflamed part to which cold is applied is surrounded by a medium from which it can not absorb motion; and, if motion can not be absorbed, inflammation can not go on. Inflammation, then, is a change attended with the absorption of motion as well as with the disintegration of matter.
Proceeding with our definition, we find it next informs us that the matter (in the present case the inflamed part) passes from a definite, coherent heterogeneity to an indefinite, incoherent homogeneity. It