text:  Again the two cases that I had witnessed coincided in characteristics; but could this coincidence be accidental? It might still be asked 'Were the phenomena displayed uncertain mutable such as might never occur again; or were they orderly invariable the growth of fixed causes which being present implied their presence also?' In fine was mesmeric sleep-waking not only a state but entitled to rank as a distinct state clearly and permanently characterized; and as such set apart from all other abnormal conditions of men? On its pretensions to be so considered rested I conceived its claims to notice and peculiar investigation: to decide this point was therefore one of my chief objects; and respecting it I was determined to seek that certainty which can only be attained by a careful comparison of facts occurring under the same circumstances