'None in the least. The machine is merely the body. It is the soul of it, the animating principle, which you can never hope to capture.'

'Exactly. But the mere mechanism seems to be a model of ingenuity.' For some time he walked round it and fingered its several parts. Then he hoisted his unwieldy bulk into the insulated chair.

'Would you like another excursion into the cosmos?' asked the inventor.

'Later, perhaps – later! But meanwhile there is, as no doubt you know, some leakage of electricity. I can distinctly feel a weak current passing through me.'

'Impossible. It is quite insulated.'

'But I assure you that I feel it.' He levered himself down from his perch.

The inventor hastened to take his place.

'I can feel nothing.'

'Is there not a tingling down your spine?'

'No, sir, I do not observe it.'

There was a sharp click and the man had disappeared. I looked with amazement at Challenger. 'Good heavens! Did you touch the machine, Professor?'

He smiled at me benignly with an air of mild surprise.

'Dear me! I may have inadvertently touched the handle,' said he. 'One is very liable to have awkward incidents with a rough model of this kind. This lever should certainly be guarded.'

'It is in number three. That is the slot which causes disintegration.'

'So I observed when you were operated upon.'

'But I was so excited when he brought you back that I did not see which was the proper slot for the return. Did you notice it?'

'I may have noticed it, young Malone, but I do not burden my mind with small details. There are many slots and we do not know their purpose. We may make the matter worse if we experiment with the unknown. Perhaps it is better to leave matters as they are.'

'And you would-'

'Exactly. It is better so. The interesting personality of Mr. Theodore Nemor has distributed itself throughout the cosmos, his machine is worthless, and a certain foreign Government has been deprived of knowledge by which much harm might have been wrought. Not a bad morning's work, young Malone. Your rag will no doubt have an interesting column upon the inexplicable disappearance of a Latvian inventor shortly after the visit of its own special correspondent. I have enjoyed the experience. These are the lighter moments which come to brighten the dull routine of study. But life has its duties as well as its pleasures, and I now return to the Italian Mazotti and his preposterous views upon the larval development of the tropical termites.'

Looking back, it seemed to me that a slight oleaginous mist was still hovering round the chair. 'But surely –' I urged.

'The first duty of the law-abiding citizen is to prevent murder,' said Professor Challenger. 'I have done so. Enough, Malone, enough! The theme will not bear discussion. It has already disengaged my thoughts too long from matters of more importance.'