Page:The American Cyclopædia (1879) Volume IX.djvu/287

INFLAMMATION 275 ing, and pain in the parts. lie compared the activity of the stimulus to that of a thorn, which gave alarm to the archaus, who imme- diately caused an increased flow of Wood to set up a defence and a reparative process. Boer- haave attributed the swelling and obstruction to a change in the texture of the blood, which he maintained grew thicker and more viscid during inflammation, acquiring what he called a state of lentor. He supposed also that the increased action of the arteries forced larger particles of the blood into vessels too small to transmit them, constituting what was termed an error loci. Cullen, in place of the doctrine of error loci, proposed that of spasm and con- traction of the capillary vessels, and taught that the system at the time possessed a peculiar condition, which he called diathesis phlogistica, consisting in an increased tone or contractility of the muscular fibres of the whole arterial system. Vacca, an Italian, abont the middle of the 18th century, proposed a theory which was advocated by Mr. Allen of Edinburgh, and which contained an opposite idea, viz., that there was a want of tone or loss of power from which there arose a stagnation of the blood and a dilatation of the vessels of the part. John Hunter taught that the blood had a vitality of its own, and to support his doctrine cited the property of spontaneous coagulation. He says : " There is a circumstance attending accidental injury which does not belong to dis- ease, viz., that the injury done has in all cases a tendency to produce both the disposition and the means of cure." The general process of acute inflammation may be described as fol- lows : If a translucent vascular membrane, as the web of a frog's foot, is sufficiently irritated by scratching it or pricking with a hot needle, there may be observed with the microscope a contraction of the capillary vessels, followed very soon by a dilatation. It is maintained by some that during the contraction the circulation is increased in rapidity, and that it is dimin- ished during dilatation ; while others maintain that the contrary action takes place in both cases, that is, that the circulation is slower in the first stage and faster in the second. This difference of opinion has arisen from not ma- king the observations under precisely the same circumstances. When a capillary is enlarged throughout its whole length, the circulation will be for a short time more rapid than nat- ural ; and when it is constricted for a consid- erable distance, it will be slower ; but if it be contracted in some places and dilated in oth- ers, the blood will move slower in the dilated places and faster in the contracted ones, as might naturally be expected from a considera- tion of ordinary hydraulic principles. After a time, however, the circulation in the dilated vessels becomes slower, and at the same time oscillating, and at last ceases, the vessel becom- ing distended with colored corpuscles. There is then an exudation of liquor sanguinis through the walls of the vessels, and occasionally, in consequence of their rupture, extravasation of blood corpuscles takes place. The oscillation of the blood, which immediately precedes stag- nation, has by some been attributed to arterial contraction and dilatation, while others have referred it to a rhythmical contraction and dila- tation in the veins, which has been observed by Wharton Jones. In the natural circulation the colored corpuscles roll forward in the cen- tre of the vessel, the space between them and the cell wall being occupied by the liquor san- guinjs and a few lymph corpuscles. In young frogs the lymph corpuscles are numerous, and under irritation are said to increase and in that way impede the circulation; but in old frogs the same changes occur without the pres- ence of lymph corpuscles. "When stagnation or " stasis " takes place, it constitutes what is called the stage of congestion. If the morbid process continues the vessels may burst, or the liquor sanguinis may transude through the walls, without rupture, into the surrounding tissue. This constitutes exudation. The con- traction of the capillaries in the first stage and their dilatation in the second are accounted for by supposing them to have the power pos- sessed by involuntary muscular fibres, and John Hunter supposed that they possessed muscular power. It is known that they have permanent cell nuclei, similar to those of the involuntary muscular fibres of the intestines. Mr. Lis- ter has found that fusiform cells, capable of contraction, are placed transversely around the vessels, which explains the fact that, like intestinal muscular fibres, they may be ex- cited to contraction by mental emotions or by local applications. The recent observations by Claude Bernard and others of the effects pro- duced by dividing the large sympathetic nerve trunk of the neck are cited by Dr. John Hughes Bennett as confirming the theory. It has been found that when innervation from whatever cause has taken place in a part, it is more prone to pass into the condition of in- flammation. In regard to the four cardinal symptoms, as they have been termed, of heat, redness, swelling, and pain (the rubor, color, cum tumore et dolore of Celsus), which were always enumerated by the older writers as constant, it has been found that some of the most fatal cases of inflammation are attended by only one or two of them, and in some cases not one of them has been present. The latent pneumonia of old people is thus graphical- ly described by Dr. Bennett: "An old man may suddenly lose his appetite 'and strength ; his respiration becomes hurried and feeble; his chest on examination is dull on percus- sion; mucous rattles are heard by the ear, and he dies. On opening his body gray he- patization has attacked the lungs, which are infiltrated with pus. He has from first to last had no pain ; there has been no heat ; on the contrary, the temperature was diminished ; no redness nor swelling is anywhere detectable. Not only, therefore, are the cardinal symptoms