When this inequality of irrigation once occurs, it is likely to increase from the consequent derangement of the feeders and drains.
The damage to the cerebellum must, it would seem, occur abruptly or quickly in order to occasion marked derangement of function, and then the derangement falls on the execution of movements.
The particulars of his case have been investigated by Dr Bucknill and Sir William Wilde, who have proved that he suffered from nothing that could be called mental derangement until the "labyrinthine vertigo" from which he had suffered all his life, and which he erroneously attributed to a surfeit of fruit, produced paralysis, "a symptom of which was the not uncommon one of aphasia, or the automatic utterance of words ungoverned by intention.
Pipes, when accurately fitted in, are much less liable to derangement than when laid in the bottom of a trench several times their width, into which a mass of loose earth must necessarily be returned.
Considering the primitive arrangement of the columns as positive, then an arrangement obtained therefrom by a single interchange (inversion, or derangement) of two columns is regarded as negative; and so in general an arrangement is positive or negative according as it is derived from the primitive arrangement by an even or an odd number of interchanges.