To the different causes which we have just mentioned, there is sometimes added another which is peculiar to one kind of sudden death. It is observed that in the midst of the same external circumstances, the blood does not always cool with the same quickness, and that in proportion as its coagulation is slower, its heat is longer preserved. Now, it is a well known fact, that when death is the result of asphyxia, the vessels are found full of fluid blood; this is also a reason which contributes to explain the slowness of the cooling. And it should be remarked, that asphyxia is one of the most frequent causes of sudden death either accidental or voluntary. BICHAT ON LIFE AND DEATH. PART THE SECOND. CHAPTER I. GENERAL CONSIDERATIONS ON DEATH. In the first part of this work, I have explained the two great divisions of life, together with the remarkable differences, which distinguish the animal existing without, from the animal existing within. I have discussed the characters which are exclusively proper to the two lives, and the particular laws, according to which they both of them commence, are developed and end in the natural order. In this second part I shall inquire in what way they accidentally finish, in what way their course is prematurely arrested. The influence of society suffers us but rarely to live out the period which was intended us by nature; while almost every other animal attains his natural end, such end in the human species is become a sort of phenomenon. The different kinds then of accidental death, should engage the particular attention of the physician and physiologist. Now this sort of death may happen in two ways: sometimes it is the result of great disturbance excited in the economy; and sometimes it is the effect of disease. In general it is easy enough to discover, according to what laws the functions are terminated in consequence of any violent or sudden attack; of apoplexy, for instance, great hemorrhagy, concussion of the brain, or asphyxia; because in such cases the organs of the body, excepting that which is immediately affected, are not the seat of any peculiar lesion, and cease to act from causes diametrically the contrary of those, which according to the common course of things maintain them in action. Now as these causes are partly known, their contraries may be inferred; besides, we are capable of imitating these sorts of death upon animals, and consequently of analyzing, experimentally, their different phenomena.