'I see there are no directions given as to the requisite dose,' he said. 'However, I do not like to keep disturbing your butler, who has now doubtless returned to his pantry and is once more settling down to the enjoyment of a well-earned rest after a day more than ordinarily fraught with toil and anxiety. Suppose we use our own judgement?'

'Certainly. Is it nasty?'

The bishop licked the cork warily.

'No. I should not call it nasty. The taste, while individual and distinctive and even striking, is by no means disagreeable.'

'Then let us take a glassful apiece.'

The bishop filled two portly wine-glasses with the fluid, and they sat sipping gravely.

'It's rather good,' said the bishop.

'Distinctly good,' said the headmaster.

'It sort of sends a kind of glow over you.'

'A noticeable glow.'