"Rather!" Kelson said. "That is why I came. I seemed to hear your voice say 'To Hyde Park--to Hyde Park--the Serpentine--the Serpentine.'" Then sinking his voice he whispered, "What's up with the policeman, he looks deuced queer?" "He's in a trance. We found him like this," Hamar said. "He is undoubtedly under the control of the Unknown. I expect it to speak through him every moment. Get ready to take down all he says. I've come prepared," and he handed Kelson and Curtis, each, a pencil and a reporter's notebook. He had hardly done so, when the policeman--a burly man well over six feet in height, who was standing bolt upright as if at "attention," his limbs absolutely rigid, his eyes wide open and expressionless--began to speak in a soft, lisping voice that the trio at once identified with the voice of the Unknown--the voice of the tree on that eventful night in San Francisco. "The great secret of medicine--the secret of healing--will now be revealed to you," the voice said. "Pay heed. In cases of tumours and ulcers take a young seringa, lay it for half an hour over the stomach of the afflicted person, then plant it with the mumia, _i.e._ either the hair, blood, or spittle of the sick person, at midnight. As soon as the seringa begins to rot, the ulcer will heal. "In phthisis pulmonalis, the mumia of the sick person should be planted with a cutting of the catalpa, after the latter has been subjected for some minutes to the breath of the diseased person. As soon as the cutting shows signs of decay, the sick person will be cured. "In diabetes, plant the mumia of the patient with a bignonia, and as soon as the latter begins to rot, the diabetes will go. "In appendicitis, cover the stomach of the sick person with a piece of raw beef, until the sweat enters it. Then give the meat to a cat, and as soon as the latter has eaten it, the patient will recover." "What becomes of the cat?" Kelson asked. "The appendicitis is transferred to it," the voice explained. "It should be killed at once. "In cancer take the sea wrack Torrek Mendrek--a weed of deep mauve colour streaked with white. It must be boiled for three hours in clear spring water (3 ozs. of wrack to half a pint of water), and then let to cool. When quite cold, a dessert-spoon of it should be taken by the sufferer every four hours--and at the end of two days the disease will have completely disappeared. The wrack is to be found at the twenty fathom level, six miles west-south-west of the Scilly Isles. "In Bright's disease, the mumia of the afflicted should be planted at 1 a.m., with a cutting of sassafras, after the latter has been slept on, for one whole night, by the sufferer. As soon as the sassafras begins to rot, the patient will be cured.