midnight
At midnight , when the moon is full , place a mirror , set in a wooden frame , in a tub of water , so that it will float on the surface with its face uppermost . Put in the water fifteen grains of bicarbonate of potash , and sprinkle it with three drops of blood , not necessarily human If the reflection of the moon in the mirror then appear crimson , the test is satisfactorily accomplished . `` No. 2 . At midnight , when the moon is full , take a black cat , place it where the moonbeams are thickest , sprinkle it with three drops of blood , not necessarily human , and rub its coat with the palm of the hand . Sparks will then be given out , and if those sparks appear crimson the test is satisfactorily done . `` No. 3 . Take a human skull -- preferably that of some person who has met with an unnatural end , pour on it a single drop of fresh , human blood -- place it on a couch , and go to sleep with the back part of the head resting on it .