[10] The condition into which Branwell fell at this period is one very well-known to mental physiologists. Thus Carpenter speaks of it: 'In most forms of monomania, there is more or less of disorder in the _ideational_ process, leading to the formation of positive _delusions_ or _hallucinations_, that is to say, of fixed beliefs or dominant ideas which are palpably inconsistent with reality. These delusions, however, are not attributable to original perversions of the reasoning process, but arise out of the perverted _emotional state_. They give rise, in the first place, to _misinterpretation of actual facts_ or _occurrences_, in accordance with the prevalent state of the feelings.'--'Principles of Mental Physiology,' (1874), p. 667. For Branwell's state of mind at this time, and for the circumstances that followed upon it, we have an exact parallel in the case of Lady Byron, after her separation from her husband. This unhappy lady, living in retirement with her friends, had maintained, for more than five years after the poet's death, relations of the most friendly nature with his sister, the Honourable Mrs. Leigh. But, at the end of that period, weakened by misfortunes and by brooding upon particular evils, her mind gave way on one point; and she made, in the full belief of their truth, the most horrible of charges against her dead husband and his sister. These charges were, by some people, believed for a time; but a very little reflection showed that Lady Byron's mind must have been unhinged, for all the acts of her life went to disprove the statements she made. It was not in the nature of things possible that she could remain on affectionate terms with her sister-in-law, had she known--as in her monomania she asserted she did--the utter depth of that sister-in-law's imagined infamy. But it is not to be supposed that the unhappy lady was visibly insane; she was, on the contrary, as all remarked, gifted with a clear and accurate observation, with a lucid and logical method of thought, and with an expression more than ordinarily calm and natural. It was precisely the same with Branwell Brontë; for, when the paroxysm of his grief was over, though he was ordinarily calm and his thoughts always clear and logical, strange impressions and misinterpretations of facts grew upon him, and he made, with all the certainty of belief, statements of circumstances relating to the lady of his dearest affections, redounding to her shame--which, had he been of sound mind, he must not only have known to be false, but would have carried, had they been true, in secrecy to the grave.