midnight
Put it in a tin vessel , mix with it three ounces of assafoetida and one drachm of quassia chips , to which add a death 's - head moth -LRB- _ Acherontia atropos _ -RRB- . Heat the vessel over a wood fire for three hours . Then remove it and place it on the hearth , rake out the fire and make the room absolutely dark . Keep watch beside the vessel , and if , at the second hour after midnight , any strange phenomena occur , the test will be known to have been satisfactorily executed . '' -LRB- _ Addendum _ -RRB- If any of these tests fail the candidate must wait for six months before giving them a further trial , and he must occupy the interim by training his thoughts in the manner already prescribed . But if , on the other hand , the tests have been successfully performed , he can proceed with the rites appertaining to the Black Art . '' Hamar had read so far when , with a gesture of impatience , he closed the book .