The Lost Casebooks of Sherlock Holmes by Donald Thomas Read Free Book Online Page A

emphatically.
    â€˜When you test that substance with nitric acid, Mr Holmes, you will find that it is arsenic. Enough arsenic to kill the poor woman twice over. There can be no doubt.’
    â€˜No doubt at all,’ Holmes agreed.
    â€˜Then there is an end of the matter,’ Mr Hardinge Giffard said, astonished at the speed of Holmes’s apparent failure. ‘There is no more to be done.’
    It was an awkward moment, some of those present feeling sorry for Sherlock Holmes in his disappointment, others resentful at having their time wasted by a trick that failed. They seemed about to turn and leave without another word.
    â€˜One moment, if you please!’ said Holmes and they turned back to him again. He addressed Dr Taylor. ‘Did you attempt to establish the presence of arsenic by the Marsh Test?’
    Dr Taylor frowned. ‘Mr Holmes, there is arsenic on the copper gauze. You may see it for yourself. You acknowledge it is there in quantity enough to commit murder. What need is there of the Marsh Test or any other experiment?’
    â€˜There is the greatest of all needs, Dr Taylor. The need of a man who will in a few days be hanged for a murder he did not commit, for a murder that was never committed by anyone.’
    Dr Taylor could not quite bring himself to leave. ‘Next you will tell us that she died of natural causes,’ he said irritably.
    â€˜Oh, I think it very likely that I shall, doctor,’ Holmes said imperturbably. ‘Indeed, I may tell you that now.’
    â€˜And that she never consumed arsenic?’
    Holmes gave a quick, impatient smile. ‘I should wager that Isabella Bankes never consumed arsenic in her life.’
    There was a murmur of laughter at the absurdity of his claim. I would have given a good deal to have been in that chemical laboratory during the next few minutes. Holmes had set up the apparatus for the Marsh Test on the next bench in the laboratory. Like the Reinsch process, the Marsh Test is essentially simple. Arsenic is the easiest poison to detect in a body because it vaporises readily. A white fragment may be dried and tested simply by a detective officer. Placed in a sealed tube and heated, it will vaporise and then condense on the inner surface of the tube. In nine times out of ten, when this occurs with a suspect specimen, it will prove to be arsenic.
    In the Marsh Test, which Holmes now conducted, the pale blue solution taken from the dead woman’s specimens was diluted with a chemical base in a retort and heated until hydrogen was given off. The gas passed into a sealed tube that was warmed—a ‘mirror’, as it was called. If arsenic was present in the gas, it would collect as a greyish substance on the inner surface of the tube. When all the hydrogen was given off, Holmes turned down the flame of the Bunsen lamp. The ‘mirror’ tube was still perfectly clean. The same solution which had just before shown enough arsenic to kill Isabella Bankes twice over now showed none at all.
    Imagine the consternation at this! Among those who watched Sherlock Holmes at work with his apparatus, there was relief and expectation among the defenders of Thomas Smethurst, dismay among those whose evidence had helped to cast upon him the shadow of the hangman’s noose.
    How could it be that one time-honoured and infallible test showed no arsenic and the other, equally honoured and infallible, enough poison to hang a man? You may be sure that Dr Taylor and his colleagues hastened to repeat these experiments, only to come to the same conclusion as Holmes. Yet one thing could not be denied. There was arsenic in the Reinsch Test, enough to bring Smethurst to the gallows.
    Rumours spread of the strange discovery and, as the world knows, there was agitation for a reprieve. The Home Secretary of the Liberal government, Sir George Cornewall Lewis, found himself caught between the process of law and an opposing clamour of the scientific