Through The Looking Glass by Lewis Carroll Chapter 4 Page 19

Tweedledee exclaimed, clapping his hands triumphantly. ‘And if he left off dreaming about you, where do you suppose you’d be?’

‘Where I am now, of course,’ said Alice.

‘Not you!’ Tweedledee retorted contemptuously. ‘You’d be nowhere. Why, you’re only a sort of thing in his dream!’

‘If that there King was to wake,’ added Tweedledum, ‘you’d go out — bang! — just like a candle!’

‘I shouldn’t!’ Alice exclaimed indignantly. ‘Besides, if I’m only a sort of thing in his dream, what are you, I should like to know?’

‘Ditto’ said Tweedledum.