Question.—“You have heard the description given by the witnesses of the symptoms and appearances which accompanied Cook’s attacks?”
Answer.—“I have.”
Question.—“Were those symptoms and appearances the same as those you have observed in the animals to which you administered strychnia?”
Answer.—“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 strychnia. 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.”
Question.—“Would poison given in pills take a longer period to operate on a human subject than on a rabbit?”
Answer.—“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 combines with the sulphuric acid, and 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 colour tests are applied to the dry residue after evaporation. Change of colour is produced by a mixture of sulphuric acid and bichromate 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 strychnia separated in its crystallised state we can recognise the crystals by their form and their chemical properties, and, above all, by the tetanic symptoms and death when administered through a wound in the skin of animals.”[44]
Question.—“Are there other vegetable substances from which, if these colouring tests were applied, similar colours could be obtained?”
Answer.—“There are a variety of mixtures which produce similar colours;[45] one of them also has a bitter taste like strychnine.[46] Vegetable poisons are more difficult of detection than mineral: 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 I first described. I have applied the tests of colouring and taste. In one case I discovered some by the colour test. In a second case there was a bitter taste, but no other indication of strychnine. In the other two cases there were no indications at all. In the case where it had been discovered by the 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. I account for the absence of any indication, because it is absorbed in the blood, and is no longer in the stomach. It is in a great part changed in the blood. When administered in large doses there is a retention of some in excess of what is required for the destruction of life.”
Question.—“Supposing a minimum dose, which will destroy life, has been given, could you find any?”
Answer.—“No. It is taken up by absorption, and is no longer discoverable in the stomach. The smallest quantity by which I have destroyed an animal is half a grain. There is no process with which I am acquainted by which it can be discovered in the tissue.[47] As far as I know, a small quantity cannot be discovered.”