456 OF NUTRITION. 



preted by the principles already laid down, as to afford a powerful confir- 

 mation to both doctrines. The usual condition of the vessels of an inflamed 

 part, is one of dilatation ; and this may be fairly attributed to the lowered 

 vitality of their walls, whereby they yield too readily to the distending force 

 of the current of blood. But this current moves too slowly; and its re- 

 tardation may gradually increase, in the part most intensely inflamed, to 

 the point of complete stagnation. Now this altered rate of movement can- 

 not be attributed to any general cause; nor can it be accounted for by the 

 change in the diameter of the vessels ; for, on the one hand, it may occur 

 with a constricted state of the vessels, whilst, on the other, in the vessels 

 surrounding the inflamed part, which partake of the dilated condition, the 

 flow of blood is so far from being retarded, that it usually takes place more 

 rapidly than usual. But it may be fairly considered as the result of the 

 lowered or suspended nutritive activity of the part, which will tend to re- 

 tard or entirely check the motion of blood in the systemic capillaries, just 

 as the want of aeration retards or checks the pulmonary circulation ( 266). 

 It is quite true that a larger amount of blood passes through a limb, of 

 which some part is in a state of active inflammation, than passes through 

 the corresponding sound limb; but this is far from indicating " increased 

 action " in the inflamed part, being dependent upon the augmented flow of 

 blood through the tissues which surround it; and if the whole of a limb be 

 in a state of inflammation passing on to gangrene (as occurs when a "frost- 

 bitten" limb has been incautiously warmed), the amount of blood which 

 passes through it is diminished. It would be just as erroneous to assume 

 the elevated temperature of an inflamed part as a sign of "increased action" 

 in it; for this elevation is no doubt attributable in part to the augmented 

 flow of blood through the surrounding vessels ; and, so far as it depends 

 upon local changes, it obviously indicates a more rapid disintegration of 

 tissue, rather than a more energetic production of it; since it is in the 

 former state, rather than in the latter, that the conditions of the develop- 

 ment of heat (on the chemical theory) are supplied, as we see that the heat 

 of a muscle is the greatest when it is being disintegrated by active exercise, 

 not when it is being repaired by the formation of new tissue in the inter- 

 vals of repose. But, as Mr. Paget justly remarks, " this phenomenon is 

 involved in the same difficulty as are all those that concern the local varia- 

 tions of temperature in the body; difficulties which the doctrines of Liebig, 

 however good for the general production of heat, are quite unable to ex- 

 plain." (See chap, xii.) And lastly, with regard to the unusual tender- 

 ness of inflamed parts, this is obviously due to such a combination of causes, 

 neither of which can be legitimately held to indicate an increase of its proper 

 vital activity, that nothing can be rested on this alone; especially as we see 

 an augmentation in the susceptibility of the sentient nerves, under many 

 circumstances (as in hysterical disorders), in which, far from an augmented, 

 there is obviously a diminished activity in the parts from which they spring. 

 -That neither an alteration in the circulation of a part, nor a departure 

 from the normal condition of its nervous supply, can be regarded as one of 

 the essential phenomena of inflammation, is obvious from this, that the most 

 important phenomena of inflammation may present themselves, as results 

 of injury or disease, in parts that have neither bloodvessels nor nerves: this 

 is seen in the deposition of lymph in the cornea, in the ulceration of the 

 cornea and of articular cartilages, and in other morbid actions in these 

 parts, which, if ever they are vascular, become so only after the effusion of 

 lymph in them, the new vessels being formed in this lymph, and not in the 

 tissues themselves. Here it is obvious that the whole change consists in a 

 perversion of the nutritive actions which the tissues ought to carry on at 



