47 



organ is augmented to such a degree, that the faintest light reaching the 

 bottom of the eye, through the transparent cornea dimmed by the con- 

 gestion of the vessels, causes in it intolerable pain. On this principle, 

 darkness is universally recommended to patients affected with ophthal- 

 mia. In like manner, when a muscle is inflamed, the action of the fibre, 

 its shortening, is prevented by the congestion in the cellular membrane, 

 which covers it and fills its interstices. The cause preventing contrac- 

 tion, or the exercise of contractility, is mechanical, and maybe compared 

 to that, which, in an inflamed lung, opposes the admission of air, and 

 the passage of the blood, from the right to the. left side of the heart. 

 Can any one call in question the increase of vital action in peripneumony ? 

 I am therefore of opinion, that the above definition is better than that 

 proposed by Bichat, in his u Anatomic Generale," a work of later date 

 than the first edition of these elements of physiology, and in which he 

 makes inflammation to consist in the increase of those vital properties 

 which he terms insensible. 



All the parts of the human body, with the exception of ths epidermis 

 and its different productions, as the nails and the hair, appear capable of 

 inflammation. One might include among these " epidermoid" parts, 

 certain dry and slender tendons, as those of the flexors of the fingers, 

 which, when pricked, lacerated and irritated in a thousand ways, are in- 

 sensible to pain, and remain uninjured in the midst of a whitlow, though 

 attended with suppuration of all the neighbouring soft parts; and when 

 exposed to the air, they exfoliate instead of granulating. Organization is 

 so indistinct in all these parts, life so feeble and languid, that they remain 

 insensible to the impression of all those causes which might tend to in- 

 crease its activity. 



The degree of sensibility in a part, the number and size of the nerves 

 and vessels which are sent into it, determine the degree of its aptitude to 

 inflammation : thus the bones and cartilages inflame with considerable 

 difficulty. When one of these parts is laid bare, the first effect of the 

 irritation to which it is exjA*t,tci, is a softening of its substance. When 

 a bone is laid bare, it bpcor*i?s ^"'Jlag'rGus uid softens, in con:-;, uacnce 

 of the abt>oi^ticr, of the phosphate of lime which fills up the interstices of 

 its tissue; and it is only after this kind of incarnation, that fleshy granu- 

 lations begin to sprout, as may be observed on the extremities ot bones 

 after amputation. The difficulty w.ith which inflammation is set up in 

 the harder parts of the body, explains why, before the twelfth or fifteenth 

 day after a fracture, it is of little consequence to wards union of the bone, 

 that the fractured ends should be placed in opposition : not that it is right 

 to wait so long, before applying the proper bandages, which are indis- 

 pensable from the first, to prevent the pain and laceration occasioned by 

 the displaced bone. The blood is determined, from all quarters, towards 

 the irritated and painful part, which swells and assumes a red colour, 

 from the presence of that fluid. 



The swelling would be unlimited, if, at the same time that the arteries 

 increase in power and calibre, to occasion that determination, the veins 

 and lymphatics did not acquire a corresponding energy, to enable them 

 to relieve the part, of the fluids which have accumulated in it, and 

 which irritation is constantly determining to it. The power of irrita- 

 bility and contractility increases with sensibility; the circulation is more 

 rapid in the inflamed part ; the pulsations of the capillary vessels are ma- 



