_Consistency._ In this respect a good deal of variation is also found; the difference depending, probably, in part upon the character of the disease, and in part upon the rapidity or slowness of the formation; those of a rapid or very recent formation, having a soft, fatty, or jelly-like character;[13] while, on the other hand, those of a more gradual formation, and with more sthenic forms of disease, acquire a considerable degree of density, the surface presenting a smooth appearance, as if acted upon by a current of blood, and in all respects resembling the dense fibrinous masses, found blocking up the cavities of aneurismal tumors. _Position._ In every case reported below, the clot has been on the _right_ side of the heart, although in some, a small, soft clot has been found on the _left_. I am not sure that I have ever found one of these clots on the left side of the heart of such a size and consistency, or under such circumstances, as to have led me to suppose that it might have been a cause of death. The body of the clot is usually found in the ventricle, extending from this, either up into the pulmonary artery, or through the opening into the auricle. In all cases, the clot has been more or less entangled with the tendinous cords of the valves and muscular columns of the heart, requiring, in some instances, considerable force to tear it away from its attachments. _Time of formation._ An important question to be decided in regard to these heart clots, is the time of their formation. Are they _ante_ or _post_-mortem in their origin? And upon the solution of this query depends the conclusion as to whether they are the _cause_ or the _result_ of death in the cases where found. That a fibrinous clot may sometimes be formed in the coagulation of the blood _outside_ of the body, is a fact well known; as in the blood drawn from patients suffering from acute inflammatory affections, where, from the retarding of the coagulation, the blood corpuscles, from their greater specific gravity, have time to fall towards the bottom of the vessel, thus giving the “buffy coat” to the upper portion of the clot. The same cause—retarded coagulation—unquestionably may give rise to a clot _in the heart_ after death, presenting the same character, viz., with the upper portion, of the buff, fibrinous character, while the lower portion, from the presence of corpuscles, will present the appearance of an ordinary blood clot. Such clots are not unfrequently found after death.