Alice in Wonderland by Lewis Carroll Chapter 5 Page 6

And yet you incessantly stand on your head —

Do you think, at your age, it is right?’

‘In my youth,’ Father William replied to his son,

‘I feared it might injure the brain;

But, now that I’m perfectly sure I have none,

Why, I do it again and again.’

‘You are old,’ said the youth, ‘as I mentioned before,

And have grown most uncommonly fat;

Yet you turned a back-somersault in at the door —

Pray, what is the reason of that?’