A spell to dispel illusions and correct wrong ideas
Place the moon at his eyes and her whiteness shall devour all the false sights the deceiver has placed there.
Place a swarm of bees at his ears. Bees love truth and will destroy the deceiver's lies.
Place salt in his mouth lest the deceiver attempt to delight him with the taste of honey or disgust him with the taste of ashes.
Nail his hand with an iron nail so that he shall not raise it to do the deceiver's bidding.
Place his heart in a secret place so that all his desires shall be his own and the deceiver shall find no hold there.
Memorandum. The colour red may be found beneficial.
This is ancient fairy magic used to drive lies from the subject and help his escape from enchantment. It is startlingly effective in destroying what the Scots call "glamour", for, as the poet Ramsay has it:
"When devils, wizards or jugglers deceive the sight, they are said to cast glamour o'er the eyes of the spectator."
The use of glamour appears to be a universal practice among fairies, and so a counterspell to protect oneself was a prudent precaution among those medieval magicians who trafficked with them. When intercourse between fairies and Christians dwindled so sharply after Uskglass' departure, such protections gradually fell into neglect - even when their texts were preserved their utility was forgotten.
Although it was included in Paris Ormskirk's Revelations of Thirty-Six Other Worlds, Ormskirk himself probably had no idea what the spell meant, or what it did. Jonathan Strange however employed this magic when he visited George III and tried to cure him of his madness. During his interview with His Majesty he noted the King seemed to be able to see a man with remarkable features (the most prominent being his thistle-down hair), who was quite invisible to Strange himself - and Strange very naturally assumed at first this person was imaginary. The king conversed amicably with this gentleman and then, seemingly drawn towards him by the music he caused to be played, gradually strayed further from safety towards a dark wood. Strange naturally accompanied him, and both Englishmen were almost lured into Lost-hope and enchanted when suddenly Strange, whose senses were more attuned to magical dangers, remembered and recited the spell; and when he recited it, it took effect, shaking off the enchantment that was cast by the gentleman with the thistle-down hair
The gentleman later describes the spell to Stephen Black as "ancient fairy magic of immense power" and is frankly astonished that someone like Strange, whose powers on the whole he rates very poorly, should have been able to use it against him.
The whole incident affects Strange in two ways: it greatly increases his respect for fairies and the potency of their magic, and also makes him realize that it is much simpler to see a fairy when one is in a state akin to madness.