Materia Medica of the Nosodes with Provings of X-Ray, by Henry C Allen, was first published in 1910, This book covers 42 remedies and includes Bernard Fincke's 1897 provings of X-Ray. Allen regarded these remedies as homeopathic and not isopathic remedies. They were to be proved as homeopathic remedies and prescribed according to the totality of symptoms. The preliminary remarks for each remedy provides about the source of the proving. Characterstic symptoms are listed with remedy differential. Systems affected is given with the identifying symptoms. The number of marks precediing the symptoms indicate the relative value of each symptoms. This work is done of the greatest contribution of Dr H C Allen to the homeopathic science.