The 'castration' (beheading) scene in 'Masque of a Savage Mandarin'

In Philip Bedford Robinson's novel Masque of a Savage Mandarin, the character Nicholas Coad seeks a human brain on which to experiment.

He pens an “Ode to the Nuclear Syndrome,” a malady he has invented. Note the references to "a five-inch length" and to "martyred Abelard," a medieval man who was castrated as punishment for an illicit sexual affair.

Thymus of a new-born whale,
Pigeon’s peritoneum,
Mix with sliminess of snail
In a hypogeum;
Belly of Sir Thomas Browne
(Urn’s a little dusty)
Spread with daffodil’s down
Till the mixture’s musty.
Take a small atomic bomb,
Say an inward prayer,
Wrap it in a toilet roll,
Throw it in the air;
Pick your entrails off the tree,
Stick the guts together,
And if you have a five-inch length
You can say you’re clever.
Send a rocket to the moon,
(mind the Fourth Dimension!)
Tie your member on the end
And calculate the tension.
The British Association
Will be loud in approbation,
And martyred Abelard
Will envy your apotheosis –
A constellation or a star
Perpetuate the new psychosis...

He advises a man that the human brain is formed from congealed semen that traveled up the spine. He persuades this man – who happens to be a preacher – that he suffers from Nuclear Syndrome, characterized by inappropriate sexual thoughts. In a move evoking the beliefs and practices of the Russian Skoptsi, he persuades the man that he must "castrate" himself, although, in this case, he is not referring to the sexual organs, but to decapitation. Thus Coad gains access to the recently deceased man's brain for his research purposes.

‘What must I do?’ he cried hoarsely. ‘What must I do to be saved? Tell me, Master!’
* * *
’You must castrate yourself,’ he said in a low, sombre voice.
The preacher started.
‘No, not in the vulgar sense,’ went on Coad, ‘but in the spiritual. The organ which is most sinful – the cerebral organ – that it is which must be excised, that it is whose vile, suggestive sinuosities must be utterly destroyed!’
‘Cut it off, I say! Cut it off and save thy soul!’
He drew a long knife out from under his cloak.
‘Take this,’ he said. ‘Take this and purge thyself.’
The preacher stared at the knife.
He took it by the handle.
* * *
He pulled it across the flesh, with a sound like the tearing of parchment.
There was an immediate gush of blood.
‘I – can’t – do – it!’ he gurgled. ‘Help me!’
Cold reached up and held the man’s hands in his own.
They sawed together. Blood spouted over Coad’s face and streamed to the ground, but with their combined strength – the preacher’s inhuman strength of martyrdom, Coad’s sublime strength of purpose – the job was done at last.
The head separated from the body and thumped to the ground, the body keeled over and lay on the roof like a heap of old clothes.

Philip Bedford Robinson. Masque of a Savage Mandarin: A Comedy of Horrors. (1969) Great Britain: Panther, 1974. Ode on p. 94. Beheading on pp. 116-117.