We submit this preliminary report on the treatment of arthritis deformans with the Roentgen rays, and hope at a later date to make a more complete report on these and similar cases and then to be able to draw more definite conclusions. Case 1. —Mr. T. J., aged 47, a miner, was admitted to the wards of the Medico-Chirurgical Hospital under the care of Dr. Anders Oct. 26, 1905. The man's father died of miner's asthma, otherwise the family history is negative. His previous medical and social history have no bearing on the disease. Present Illness. —This dates from July, 1902, when his feet, especially the joints of the toes, became swollen, tender and painful. This kept him from work one year; he then improved and was able to work four months. Since that time, which was fifteen months before admission to the hospital, he has not worked on account