Dictionary.net

One who formerly examined the bodies of the dead to report as to the cause of death. In the time of the plague this was done by "the chirurgeons," who were allowed" twelve pence," to be paid out of the goods of the party searched, if able; otherwise, by the parish. Until of late, this office was executed in England by two old women-called 'searchers'; and hence the imperfections of the Bills of Mortality. In plague times, the office was an important one; and, it is stated, that a noted searcher, named Snacks, finding his business increase so much, that he could not transact it alone, offered to any one who would join him in its hazards, half the profits; and they who joined him were said to "go with Snacks." Hence, the saying "to go Snacks," or to divide the spoils.-Wadd.