In the magic properties of this rod he was an ardent believer, and he wrote an elaborate dissertation upon its uses, which has been published. It is entitled “Observations on the Properties of the Virgula Divina,” and contains, from beginning to end, such a series of statements as would do well to go side by side with the tales of spririt-rapping in our day, and which make one wonder at the amount of credulity that a clever man may occasionally exhibit. So ardent a believer was he in the value of this rod, that he did not hesitate to uphold it in the presence of men of high scientific attainments, and to carry on experiments occasionally to prove to them its correctness. As might be expected, on most occasions these experiments failed, but the operator had always some good reason ready to be assigned for the mishap. On one occasion, after having warmly descanted on its properties to Dr. Mudge and Dr. Johnson, he agreed to try in his own garden the experiment as to whether any metal was to be found beneath its surface, affirming that if metal, whether large or small in quantity, and at whatever depth, existed, the rod would immediately indicate its whereabouts. The doctors having previously taken the precaution to have one of Cookworthy’s large iron mortars, used in his laboratory, buried in one corner of the garden, unknown to him, the examination with the rod was gravely made, and resulted in Cookworthy triumphantly affirming that no metal existed on the spot. The learned doctors then, in his presence, dug out the mortar to prove that he was wrong, and had signally failed in his trial. Cookworthy, nothing disconcerted, however, immediately exclaimed, “Ah, that’s an amalgam! my rod has no sympathy with amalgams,” and thus spoiled their joke, and kept his own position at the same time. His journeys into Cornwall, however, were productive of much more important results than the fabulous properties of the divining rod, for it was in these journeys that he succeeded in discovering, after much anxious inquiry and research, the materials for the manufacture of genuine porcelain. The information given him by the “Quaker” in 1745 had never been lost sight of, and he prosecuted inquiries wherever he went. After many searchings and experiments, he at length discovered the two materials, first in Tregonnin Hill, in Germo parish; next in the parish of St. Stephen’s; and again at Boconnoc, the family seat of Thomas Pitt, Lord Camelford. There is a kind of traditionary belief that he first found the stone he was anxious to discover in the tower of St. Columb Church, which is built of stone from St. Stephen’s, and which thus led him to the spot where it was to be procured. At this time he lodged at Carlogges, in St. Stephen’s parish, with a Mr. Yelland, and was in the habit of going about the neighbourhood with his “dowsing rod,” in search of mineral treasures. This discovery would probably be about 1754 or 1755.