There exists still much difference of opinion as to the part played by cancer in the ætiology of insanity. In the case here related by Jacquin, he believes that the malignant tumour was a strong factor in the causation of the insane attack; but it is important to remember that injections into the body of the tumour were made, and that some septic mischief was set up thereby. A woman, æt. 31 years, was admitted into the Hospital de la Croix-Rousse (Lyon) on July 3rd, 1899, with a swelling on the right side of the neck of the size of a walnut, thought to be lymphadenoma. Three days later iodoform with ether was injected into the tumour after incision. After a few days' suppuration the wound healed. Three months later, the patient returned with the tumour a good deal larger—the size of a small fótal head. There was a good deal of pain, and signs of pressure on the right brachial plexus were present. Every third day arsenical injections were made into the tumour without any result. On November 29th, the patient was admitted into Bron Asylum suffering from delusions of persecution, with hallucinations of hearing and sight. From a fistulous opening in the tumour, very fótid blood-stained matter escaped. There was marked cachexia. The delusions and hallucinations persisted, fever set in, the general condition grew worse, and the patient died on February 12th. There was no autopsy.