I shall refer to these men and women as the sitters. We generally select an equal number so far as sex is concerned; and, in addition, we endeavor to obtain an equal number of persons possessing either positive or negative temperaments. In this way we form the sitters into a powerful human battery, the combined force given off by them (if the battery is properly arranged, and the individual members of that battery are in good health) proving of enormous assistance during our experiments. If in ill-health, we find that a man or woman is useless to us, for we can no more expect to obtain the necessary power from such an individual than we can expect to produce an electric spark from a discharged accumulator, or pick up needles with a demagnetized piece of steel. We are told to remember always that "all manifestations of natural laws are the results of natural conditions." * * * * * Minor details too, we find, must be thought out most carefully if we are to provide what we may term ideal conditions. The chairs should be made of wood throughout, those known as Austrian bentwood chairs, having perforated seats, being proved to be the best for the purpose. The sitters should bathe and then change their clothing--the ladies into white dresses, and the men into dark suits--two hours before the time fixed for the experiment, and should then at once partake of a light meal--meat and alcohol being strictly forbidden--so that the strain upon their constitutions during the experiment may not interfere with their health. Trivial as such matters must appear to the man in the street, we are told they must all be carried out most carefully, in order that the finest conditions possible may be obtained, the one great object of the sitters being to give off all the power--and the best kind of power--that they are capable of producing, in order that sufficient suitable material may be gathered together from the sensitive and themselves, with which a temporary body may be formed for the use of any entity wishing to materialize in their presence. PRECAUTIONS AGAINST FRAUD We are now ready to see what happens at a typical experimental meeting for these materializations, at hundreds of which I have assisted, having the services of no less than six sensitives placed at my disposal for this purpose. I will endeavor to describe what I should consider to be an ideal one, held under ideal (test) conditions. Our imaginary test meeting is to be carried out--as it was on one occasion in London--in an entirely empty house, which none of us has ever entered before, a house which we will hire for this special event. By doing this we may feel sure that all possibility of fraud, so far as the use of secret trap-doors, large mirrors, and other undesirable things of that description are concerned, can be successfully thwarted.