Gifford’s suggestion (“Braintipped - That is, the scalp tingles with pleasurable excitement”) seems more like inspired guesswork than lexicographically sound. The evidence of contemporary usage points to a more radical transformation brought about by Flotow’s music and Simon Dedalus’ tenor voice:
Woman, Who Said She Was Once
a Boston teacher, Asked for a
Warrant for the Arrest of Presi-
Boston Morning Journal (1901), 28 February
He leaned back in his seat, tearing his eyes from the racing horizon, whose speed set his brain tipping.
Walter Archer Frost, The Man Between (1913), ch. 15 p. 145
"Well, his brain tipped over," said the coroner's official, "that letter was written by a crazy man."
Vance Thompson, Mr. Guelpa: A Novel (1925), p. 205
The word formation echoes an older one: brain-touched.
The sketches — for they are only sketches — of Miss Flite, the little woman, brain- touched — of Guppy, of Richard and Ada, Jobling and others, are all, more or less, graphically hit off.
Southern Quarterly Review (1854), January p. 227
"And Robert Hagburn having to bring a message from camp to the selectmen here, had it in charge to bring the girl, whom his mother has taken to board."
"Then the poor thing is crazy?" asked Septimius.
"A little brain-touched, that is all," replied Rose, "owing to some grief that she has had; but she is quite harmless [...]"
Nathaniel Hawthorne, Septimius Felton: or, The Elixir of Life (1872), p. 77
Bloom’s later musing seem to confirm the meaning of both words: of unsound mind, mentally “touched”, mad - and denoting, in the case of brain-tipped, a state in which the brain has tipped from reality towards delusion or delirium:
Cowley, he stuns himself: kind of drunkenness […] Instance enthusiasts. All ears. Not lose a demisemiquaver. Eyes shut. Head nodding in time. Dotty. (U 11.1191-3)
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