In connection with the appearances depen dent upon the slow coagulation of fibrine, may here notice the occurrence of what have been termed polypi, or more recently and cor rectly, false polypi in the heart and larger ves sels. These are so common, that, as Haller ob serves, scarcely a body is met with in which they do not exist. They are found in both auricles and both ventricles and in the larger arteries and veins, as well of the trunk as of the extremities. They consist essentially of fibrine, and partake of all the varieties that are obser vable in the fibrinous coat of buffed blood. Haller affirms, as usual, supporting his opinion by numerous authorities, that these have been known to exist even during life, not only in man but in the larger warm-blooded animals, and adverts to a disease, la gourine, common among horses, which arises from a coagulation of the blood in the large arteries and veins and in the heart. Thackrah is of the same opinion, and Dr. George Burrows, who has made the changes which take place in the blood when its circulation is stopped in the living body, the subject of the Croonian Lectures of the present year, states that " there can be but little doubt that in some cases the blood coa gulates in the heart during life. The firmness of the clots found in its cavities after death— their close adhesion to the lining of the heart— the presence of various fluids in the centre of these clots—the occasional organization of the coagulated masses, and their partial conversion into structures which are similar to new growths in other parts of the body—are facts which lead us to the conviction that the blood often coagulates in the heart long prior to death." That such coagulation may take place during life I am willing to admit, but I am by no means led to the conviction that such an event often occurs. To the formation of a firm coa gulum I am persuaded that rest is absolutely necessary, and I must consider it as a very rare occurrence that the contents of the cavities'of the heart should be at rest during life. The usual appearance of false polypi is such as would take place in blood that coagulated very slowly, whether in or out of the body. Mr. Thackrah has proved that the blood when at rest coagu lates much more slowly in living vessels, among which his experiments include vessels recently removed from living animals,* than in those that are dead ; and I conceive that the human body, long after the heart has ceased to beat, and when it is, in the common accepta tion of the term, dead, is still endowed, like the vessel just separated from the living animal, with a sufficient share of vitality to keep the blood which is in the heart and larger vessels in a fluid state, and thus to permit its coagula tion to take place at length far more slowly than under ordinary circumstances. The fol lowing fact will perhaps be considered to have some interest as bearing on this point. I was engaged in the post-mortem examination of a gentleman who had died apoplectic from soft ening of the brain, which had given rise to effu sion into the ventricles and under the pia mater; and being desirous of examining the fluid thus effused, I collected it with a clean sponge, by successively dipping this into the ventricles, and squeezing the fluid into a small cup. With a view to increase the quantity, I used the sponge also in soaking up some of the same fluid which had been caught in • the calvaria, but was somewhat tinged with red particles. The cup was set apart till the conclusion of the ex amination, which lasted an hour and a half, when, on proceeding to transfer its contents to a phial, I was not a little surprised to find that a bulky clot of a rose colour and perfectly dis tinct was formed in the fluid. The examina tion in question took place twenty-two hours after death. As long as galvanism will stimu late the muscular structures to convulsive movement, so long at least may we conceive such a portion of vitality to remain as will in fluence the state of the blood. The fluid thus circumstanced exhibits the same phenomena, though in a more marked degree, which we ob serve in buffed blood out of the body. The red particles subside and leave the liquor san guinis free from colour. In due time this separates into fibrine and serum : the coagula tion takes place uniformly and universally, and in the larger cavities and vessels a colourless clot is left, which is moulded into their exact shape. The serum drains off, and washes away the red particles into the more depending and distant vessels. Thus it is that where we find polypi in the heart, we often find the descend ing aorta and the vena cava inferior filled with fluid, in which there is no fibrine at all. The firmness of a polypus affords no proof that it existed during life, or rather before respiration and circulation had ceased ; for what can be firmer than the buffed coat which we often see formed out of the body ? Its close adhesion to the lining of the heart is generally in appearance only, and is occasioned by the exactness with which it has adapted itself to every cavity and sinus, and enveloped every column, and the force with which the heart itself has contracted upon it. The presence of fluid in the centre, however difficult to account for, is also occa sionally met with in the crassamentum of blood abstracted from the arm ;* and even purulent matter, said to be found in false polypi, is oc casionally formed out of the body. " ln some rare cases I have seen the fibrine," says Andral, cc assume a different aspect. The blood had no clot, and instead of it we observed at the bottom of the basin a kind of homogeneous purulent matter of a deep brown or dirty grey colour, and rather resembling sanies than blood." With regard to the existence of organization, it seems to me that sufficient distinction has not usually been made between those cases where the lining membrane of the cavities of the heart or vessels has been ruptured, and which in so far are of the character of aneu rism, and those where that membrane has re mained entire. I am willing to admit that
where there is a lesion of surface, adventitious growths will readily spring from it ; but their substance is furnished from the structure be neath, and not from the circulating fluid. As an instance, I may mention the case of a youth who, being in perfect health, received a sudden shock from the unexpected discharge of a pistol close to his ear. He immediately felt conscious that something had given way in his heart, and from that hour suffered from palpitation, occa sional syncope, with the usual symptoms of obstructed circulation, and died of general dropsy at the end of eighteen months. On ex amination after death the mitral valve was found to be obstructed by a fringe of excre scences, originating no doubt from a rupture of the valve itself, which had taken place at the time of the sudden surprise. This kind of growth, as well as that which is formed on the inflamed surface in endocarditis, has a suffi ciently evident origin. We can also readily account for organized structures arising from aneurisms of the heart or arteries, accidental wounds of the latter vessels, ruptures of their inner membrane by ligatures, or its destruction by inflammation. I can, however, imagine nothing more unlikely than that an insulated mass of fibrine owing its origin to the mere coagulation of the blood from rest, and there fore only by gravitation brought in contact with the sides of the vessel which may contain it, should assume an organized structure, and that, too, at a time when the powers of life are so much enfeebled that the heart itself ceases to perform its office. I have looked carefully for unequivocal signs of vitality in these false polypi, and I confess that I have never been able to satisfy myself of its existence.
The albumen has not been demonstrated to be subject to alteration in quality. Its distin guishing characteristic of coagulating by heat is preserved even after it has become in the high est degree offensive from putridity.* It may be excessive or defective in proportion, and M. Gendrin has shewn that under inflammation of the system, the serum contains twice as much albumen as in the healthy state. Andral affirms that even by the touch, we may, from its vis cidity, recognise serum that is surcharged with albumen. Its specific gravity, however, of which the French writers seem to take little note, would be a far better guide, and would indicate alike the defect as the excess of this principle. M. Gendrin has occasionally ob served a mucous layer either at the bottom of the serum, or suspended in it. This is, in all probability, a minute portion of fibrine se parating in the form of a flocculent cloud ; for serum is capable of holding a certain portion of fibrine in solution, which after a time separates from it. This was first proved by Dr. Dowler,t who, on pressing the buffed coat of blood, ex tracted from it a liquid serum, which, on being allowed to rest for some time, exhibited signs of coagulation. With regard to the relative proportions of the serum and the clot, I have proved elsewhere I that this depends much on the vessel into which the blood is received. I shall show experimentally, however, in treating of diseased kidney, that an opposite state to that above alluded to as occurring, according to M. Gendrin, in inflammation, takes place under certain forms of disease where albumen is passing out of the system by the urinary pas sages. Thackrah lays it down as a law, to which he has found no exception, that in all cases in which the proportion of fibrine is con siderably above the normal standard, the solid matter in the serum is below it. He cites ten examples in proof of his assertion, and puts it as a question whether we may not hence sup pose that the albumen is taken from the serum for the formation of fibrine ? The fact itself, however, requires confirmation, being in direct opposition to M. Gendrin's statement, that the proportion of albumen is greatly increased in an inflammatory condition of the system, which is precisely that condition when in general we find buffed blood, and therefore, according to Thackrah, an increase in the proportion of fibrine.
The hmmatosine is the least destructible of all the elements of the blood, retaining its quali ties in that fluid after having been kept for several years. It is liable to much variety in its proportion, and in all those diseases and states of system in which hemorrhages occur, it gradually diminishes, at least to a certain point, in proportion to their extent and duration. In what part of the system the red particles are elaborated remains for the present a mys tery. That they are reproduced slowly is manifested by the fact that those who have suf fered large losses of blood, remain exsanguine for many months or even years afterwards. The same conclusion may also be deduced from the circumstance that women have a smaller proportion of red particles than men, the difference having been shewn by M. Le canu to be attributable to the monthly loss which they habitually experience. Besides change of colour, to which the red particles are liable during disease, and which, among other causes, may arise from an altered proportion in the saline matters contained in the blood, they also appear to undergo structural alterations. In fevers, in malignant diseases, in sea-scurvy, in cases of poisoning, and of asphyxia from light ning, a permanently liquid state of the blood occurs, wherein the colouring matter of the globules appears to have lost its character of insolubility in the serum, and to be capable of percolating those tissues which are otherwise destined to contain it. Passive hemorrhages, petechim, and ecchymoses, are the results during life ; and, after death, a stained condition of the lining membrane of the heart, the arteries, and veins, which has often been mistaken for vas cular congestion of these parts.