STATE OF THE CHIEF ORGANS AFTER DEATH FROM CHLOROFORM.
A few years ago, I examined the viscera of the chest, and kept notes of the appearances, in thirty-seven animals killed by chloroform. They consisted of two dogs, twenty-two cats, one kitten, three rabbits, three guineapigs, two mice, two larks, and two chaffinches. Many of the animals were opened immediately after death, and the rest within a day or two. The lungs were not much congested in any instance. In seven of the animals, they were slightly congested; but in the remaining thirty, they were not congested. They were generally of a red colour, but in a few of the cats they were quite pale. I ascertained the specific gravity of the lungs of two of the cats, in which they presented the amount of vascularity I have most usually met with. The specific gravity was 0·605 in one instance, and 0·798 in the other. As many of the animals died in a way resembling asphyxia, the respiration ceasing before the circulation, it might at first be supposed that we should meet with the same congestion of the lungs; but by the time that the respiration is altogether suspended by the action of chloroform, that agent has begun already to influence the heart, which does not inject the blood into the lungs with the same force as when the respiration is mechanically prevented, whilst it is in full vigour. Besides, in the gaspings which so often take place when the heart is ceasing to act, the animal inhaling chloroform draws air freely into the lungs, whilst the asphyxiated animal is prevented from doing so.
As regards the condition of the heart, it was found in the two chaffinches that the auricles were filled with blood, whilst the ventricles were empty. The condition of the heart in the larks is not mentioned, but in all the thirty-three quadrupeds, the right auricle and ventricle were filled with blood. In ten of them, these cavities were much distended; and in some of these instances, the coronary vessels on the surface of the heart were distended also. The left cavities of the heart never contained more than a small quantity of blood, not exceeding a quarter of what they would hold.
The head was examined in only ten of the animals. The substance of the brain was found to be of the natural vascularity, and the sinuses were not very much distended, except in two instances.
With respect to the state of the blood, it may be mentioned, that in every instance in which the chest was opened within an hour after death, the blood which flowed from the cut vessels coagulated immediately and firmly. In eighteen of the animals in which the blood was examined in the heart or large vessels, a day or two after death, it was found to be well coagulated in ten, loosely coagulated in seven instances, and quite fluid in one instance. I have not met with air in the bloodvessels, either in the above thirty-seven examinations, or in any of the numerous other animals that I have opened, after they have been killed by chloroform. The appearances I have met with in animals killed by this agent have usually been such as I have described in the above thirty-seven instances; but I long since ceased, as a general rule, to make careful notes of the appearances, as I did not meet with anything new.
In the fatal cases of inhalation of chloroform previously quoted, the lungs are related to have been congested more frequently, and to a greater extent, than I have met with in animals. But there is no standard of what should be called congestion; and probably many of the medical men who made the examinations were speaking by comparison with cases where persons die after illness, in a state of inanition. In the human subject, the right cavities of the heart, although generally full of blood, were found empty in several cases; but as I previously stated, it is almost certain that they were emptied after death, either by the artificial respiration which was employed, or in some other way.
The blood remained fluid in eighteen out of twenty-five cases of fatal accident from chloroform, in which an examination of the body was made and the condition of the blood recorded; whereas it was only quite fluid in one instance out of eighteen of the animals which were killed by chloroform, and not opened till a day or two afterwards. The fact of the blood coagulating more generally, in the animals on which I have experimented, than in the human subjects who died from chloroform, is probably due to their smaller size. I was formerly of opinion that the fact of the body of a small animal cooling more quickly than the human one was the probable explanation of this, but Dr. Richardson appears to have proved that the blood is kept in a liquid state by the presence of ammonia; and ammonia, we might expect, would escape more readily from the body of a small animal than from the human body. However this may be, it is pretty certain that the blood generally remains fluid in the human body after death from chloroform, only because it usually remains fluid in every kind of sudden death. When a patient dies slowly of illness, the body cools gradually before death takes place, and ammonia keeps exhaling in the breath, if Dr. Richardson is correct, whilst the formation of this alkali must be almost suspended. In many cases, we know that coagulation of the blood commences before the respiration and circulation have ceased. The blood which flows during surgical operations coagulates as quickly and firmly when the patient is under the influence of chloroform as at other times; and, as was mentioned above, the blood which flows from animals, just after they are killed by this agent, coagulates as well as usual; it follows, therefore, that if the coagulation of the blood were prevented by the chloroform, and not by the mere fact of sudden death, it would be by the presence of this agent in the blood after death, and not by any action which it exerted during the life of the patient.