I have just said that there were three methods employed in our spiritistic experiments. I have given my opinion of the first (writing mediums), basing it on my personal observations, and without desiring to weaken other proofs, if there are any. As to the second (planchette), I became familiar with it more especially by the seances of Mme. de Girardin, at the home of Victor Hugo in the Isle of Jersey. It works more independently than the first method; but it is still only a prolongation, as it were, of the hand and the brain. The third method--table-rapping, or typtology; I mean taps in the table--seems to me still more emphatically an extension of the hand and brain, and some forty-five years ago I often made use of this form of experiment. Rappings made on the floor by one foot of the table, as letters are spelled out, have no special value. The least pressure can produce these see-saw movements. The chief experimenter himself makes the responses, sometimes without suspecting it. Several persons group themselves about a table, place their hands upon it, and wait for something to happen. At the end of five, ten, fifteen, twenty minutes, the time depending on the psychic atmosphere[8] and the faculties of the experimenters, raps are heard in the table, or the sitters help in the movements of the table, which seems possessed. Why choose a table? Because it is the only article of furniture around which folks usually sit. Sometimes the table is lifted on one or more of its feet and is gently rocked to and fro. Sometimes it comes up as if glued to the hands placed on it, remaining suspended in the air two, three, five, ten, twenty seconds. Again, it is nailed to the floor with such force that it seems to have double or triple its usual weight. At other times, and usually on demand, it gives forth the sound of a saw, of a hatchet, of a lead-pencil writing, etc. We have here material results coming under direct observation, and they prove irrefragably the existence of an unknown force.