Could you detect any injury in the stomach?—No. I have found in some cases congestion of the membranes of the spinal cord to a greater extent than would be accounted for by the gravitation of the blood. In other cases I have found no departure from the ordinary state of the spinal cord and the brain. I ascribe congestion to the succession of fits before death. In a majority of instances, three out of five, I found no change in the abnormal condition of the spine. In all cases the heart has been congested, especially the right side. I saw a case of ordinary tetanus in the human subject years ago, but I have not had much experience of such cases. I saw one case last Thursday week at St. Bartholomew’s Hospital. The patient recovered.
You have heard the descriptions given by the witnesses of the symptoms and appearances which accompanied Cook’s attacks?—I have.
Were those symptoms and appearances the same as those you have observed in the animals to which you administered strychnine?—They were. Death has taken place in the animals more rapidly when the poison has been administered in a fluid than in a solid form. They have died at various periods after the administration of the poison. The experiments I have performed lately have been entirely in reference to solid strychnine. In the first case the symptoms began in seven minutes, and the animal died (including those seven) in thirteen minutes. In the second case the symptoms appeared in nine minutes, and the animal died in seventeen. In the third case the symptoms appeared in ten minutes, and the animal died in eighteen. In the fourth case the symptoms appeared in five minutes, and death took place in twenty-two. In the fifth case the symptoms appeared in twelve minutes, and death occurred in twenty-three. If the poison were taken by the human subject in pills it would take a longer time to act, because the structure of the pill must be broken up in order to bring the poison in contact with the mucous membrane of the stomach. I have administered it to rabbits in pills.
Would poison given in pills take a longer period to operate on a human subject than on a rabbit?—I do not think we can draw any inference from a comparison of the rapidity of death in a human subject and in a rabbit. The circulation and absorption are different in the two cases. There is also a difference between one human subject and another. The strength of the dose, too, would make a difference, as a large dose would produce a more rapid effect than a small one. I have experimented upon the intestines of animals, in order to reproduce the strychnia. The process consists in putting the stomach and its contents in alcohol, with a small quantity of acid, which dissolves the strychnia, and produces sulphate of strychnia in the stomach. The liquid is then filtered, gently evaporated, and an alkali added—carbonate of potash, which, mixed with a small quantity of sulphuric acid, precipitates the strychnia. Tests are applied to the strychnia, or supposed strychnia, when extracted. Strychnia has a peculiar strongly bitter taste. It is not soluble in water, but it is in acids and in alcohol. The colouring tests are applied to the dry residue after evaporation. Change of colour is produced by a mixture of sulphuric acid and bi-chromate of potash. It produces a blue colour, changing to violet and purple, and passing to red; but colouring tests are very fallacious, with this exception—when we have strychnine separated in its crystallised state we can recognise the crystals by their form and their chemical properties, and, above all, by the production of tetanic symptoms and death when administered through a wound in the skin of animals.
Are there other vegetable substances from which, if these colouring tests were applied, similar colours would be obtained?—There are a variety of mixtures which produce similar colours. One of them has also a bitter taste like strychnia. Vegetable poisons are more difficult of detection, by chemical process, than mineral poisons; the tests are far more fallacious. I have endeavoured to discover the presence of strychnine in animals I have poisoned in four cases, assisted by Dr. Rees. I have applied the process which I first described. I have then applied the tests of colouring and of taste.
Were you able to satisfy yourself of the presence of strychnia?—In one case I discovered some by the colour test. In a second case there was a bitter taste, but no other indication of strychnia. In the other two cases there were no indications at all of strychnia. In the case where it was discovered by a colour test two grains had been administered; and in the second case where there was a bitter taste, one grain. In one of the cases where we failed to detect it one grain, and in the other half a grain had been given.
How do you account for the absence of any indication of strychnia in cases where you know it was administered?—It is absorbed into the blood, and is no longer in the stomach. It is in a great part changed in the blood.
How do you account for its presence when administered in large doses?—There is a retention of some in excess of what is required for the destruction of life.
Supposing a minimum dose, which will destroy life, has been given, could you find any?—No. It is taken up by absorption, and is no longer discoverable in the stomach. The smallest quantity by which I have destroyed the life of an animal is half a grain. There is no process with which I am acquainted by which it can be discovered in the tissues. As far as I know, a small quantity cannot be discovered.
Suppose half a grain to be absorbed into the blood, what proportion does it bear to the total quantity of blood circulated in the system?—Assuming the system to contain the lowest quantity of blood, 25lbs., it would be 1-50th of a grain to a pound of blood. A physician once died from a dose of half a grain in twenty minutes. I believe it undergoes some partial change in the blood, which increases the difficulty of discovering it. I never heard of its being separated from the tissues in a crystallised state. The crystals are peculiar in form, but there are other organic crystallised substances like them, so that a chemist will not rely on the form only. After the post-mortem examination of Cook a portion of the stomach was sent to me. It was delivered to me by Mr. Boycott, in a brown stone jar, covered with bladder, tied, and sealed. The jar contained the stomach and the intestines. I have experimented upon them with a view to ascertain if there was any poison present.