“Ah, Mr Blake. So glad you could make it. Do come in.”

The man ushering William Blake into his opulent townhouse was a natural philosopher, an alchemist, and the owner of a splendid private menagerie.

“I had better make sure you are the right Mr Blake,” he gabbled as he steered Blake into the lobby, “You are the poet and engraver and angel-spotter and occasional nudist?”

William Blake nodded in affirmation.

“Good, good,” said his host, “Let us go then, you and I. Come into the garden, Maud, ha ha!, to quote a pair of poems yet unwritten.”

Blake’s eyes boggled as he entered the garden at the back of the townhouse. It was a teeming profusion of vegetation, wild and uncultivated.

“It is like a forest,” he said.

“It is not like a forest, Mr Blake. It is a forest!” said the other, and when he spoke, from somewhere in the garden came the howling of monkeys and the cawing of strange exotic birds.

“But this is what I have brought you to see, Mr Blake,” and he pointed towards a great stone slab surrounded by choking weeds, upon which was heaped a pile of kindling.

“If, Mr Blake, you are thinking that it looks like a funeral pyre, you are correct. But we must wait for nightfall. Come, let us repair to the gazebo and drink lemonade.”

And as William Blake drank from a pewter tankard of lemonade in the gazebo, his companion told him a startling thing.

“In the course of my alchemical researches, Mr Blake, I had occasion to discover an elixir, of potable gold and several other ingredients, the drinking of which, unlike this lemonade, has conferred upon me eternal youth. I cannot die. I am immortal!”

Blake could only gawp. The sun sank below the horizon.

“At last it is night time!” said his host, “Come, let us return to the great stone slab! My assistant, Mungo, should be waiting for us there.”

As indeed he was, a shrivelled and hunchbacked monstrosity with one mad eye. Blake noticed that he was holding a length of chain, the other end of which was concealed in the shrubbery.

“The time has come!” cried the alchemist, “Pull, Mungo!”

With inhuman strength, Mungo tugged at the chain, and Blake saw to his horror and amazement a tiger, dragged from its lair in the lupins and hollyhocks and petty spurge. The hunchback somehow managed to pull the tiger up on to the pyre, and once it was there he shortened the chain and bolted it to the slab.

“Excellent work, Mungo,” said the alchemist, “Now go to the gazebo and have a refreshing drink of lemonade, then come back with the Swan Vestas.”

Mungo lurched off, and as he did so, the alchemist turned again to William Blake, who was still gawping.

“Do you notice something curious about that tiger, Mr Blake? Look carefully. Do you see? It is entirely symmetrical. In one of my experiments I set out to breed symmetrical cats, big and small. I am convinced that the sight of such creatures will strike fear into those who observe them. Well? Are you fearful, Mr Blake?”

He was. Such was his terror that William Blake ran screaming from the garden, back through the opulent townhouse.

“Wait, Mr Blake, wait!” cried the alchemist, “You will miss the burning of the symmetrical tiger, the culmination of my madcap schemes!”

But William Blake had fled, wandering thro’ each charter’d street, near where the charter’d Thames does flow.