"We have already spoken of the action which the sun's light had upon her in producing physical effects. Among others it was observed that the different colored rays produced each a specific effect. The light of the moon, also, when she looked at it, produced coldness and shivering, with melancholy." The effects of these agents on the human organism are clearly explained, in the numbers of an astronomical paper, by Mr. Chapman, of Philadelphia.
"On touching Frederica with a finger, during an electrical state of the atmosphere, she saw small flashes, which ascended to the ceiling; from men these were colorless, from women blue; and she perceived emanations of the same kind, and of the same variation of color, from people's eyes."
Concerning the power possessed in the nerve centres of this woman, to produce sounds at a distance, Dr. Kerner remarks as follows: "As I had been told by her parents, before her father's death, that, at the period of her early magnetic state, she was able to make herself heard by her friends, as they lay in bed at night, in the same village, in other houses, by a knocking,--as is said of the dead,--I asked her, in her sleep, whether she was able to do so now, and at what distance. She answered that she could sometimes do it. Soon after this, as we were going to bed, (my children and servants being already asleep,) we heard a knocking, as if in the air over our heads; There were six knocks, at intervals of half a minute. It was a hollow, yet clear sound, soft, but distinct. We were certain there was no one near us, nor over us, from whom it could proceed; and our house stands by itself. On the following evening, when she was asleep, (we had mentioned the knocking to nobody whatever,) she asked me whether she should soon knock to us again; which, as she said it was hurtful to her, I declined." And yet, not long after this, Kerner relates the following, as having taken place at his house: "On the morning of the 23d of March, 1837, at one o'clock, I suddenly awoke, and heard seven knocks, one after another, at short intervals, seeming to proceed from the middle of my chamber: my wife was awakened also; and we could not compare this knocking to any ordinary sound. Mrs. Hauffe lived several houses distant from us."