The reader is asked to refer to the general conditions of the case of Mr. C. testified to by Professor Barrett in the previous chapter. He says:-- "They (the sounds) came more readily and more loudly when music was played, or a merry song struck up. Usually they kept time with the music, and altogether displayed a singular degree of intelligence. Sometimes a loud rhythmic scraping, as of a violoncello bow on a piece of wood, would accompany the music. Again and again I placed my ear on the very spot on the table whence this rough fiddling appeared to proceed, and felt distinctly the rhythmic vibration of the table, but no tangible cause was visible either above or below the table.... On one occasion, when no one else was in the room, ... I asked my young friend the medium to put her hands against the wall, and see how far she could stretch her feet back from the wall without tumbling down. This she did, and whilst in this constrained position--with the muscles of arms and legs all in tension--I asked for the knocks to come. Immediately a brisk pattering of raps followed my request. All the while the child remained quite motionless. My reason in making this experiment, was to test the late Dr. Carpenter's muscular theory of the cause of the sounds. Had Dr. Carpenter been present, I feel sure he would have admitted that here at any rate that theory fell through."[13] Professor Barrett sums up his conclusions on this case thus:-- "A long and careful examination convinced me that trickery on the part of the child was a more improbable hypothesis than that the sounds proceeded from some unknown agency. Nor could the sounds be accounted for by trickery on the part of the servants in the house, for in addition to my careful inquiries on this point, Mr. C. informed me that he had obtained the raps on the handle of his umbrella out of doors, when the child was by his side; and that the music-master complained of raps proceeding from inside the piano whenever the child was listless or inattentive at her music lesson. Mrs. C. told me that almost every night she heard the raps by the bedside of the child when she went to bid her good-night; and that after she had left the room and partially closed the door, she would hear quite an animated conversation going on between her daughter and her invisible companion, the child rapidly spelling over the alphabet, and the raps occurring at the right letters, and the child thus obtaining with surprising rapidity a clue to the words spelt out. "Still more violently improbable is the supposition that the parents of the child were at the bottom of the mystery, stimulated by a desire to impress their friends with the wonderful but imaginary gifts their child possessed. The presence of the parents was not necessary for the occurrence of the sounds, which, as I have said, often took place when I was the only person in the room besides the child.