On the action of radium rays upon the cells of Jensen's rat sarcoma

The experiments of B. H. Wedd and one of us have shown that if freshly excised portions of mouse carcinoma are exposed do X-rays or the β-rays from a few milligrammes of radium for a comparatively brief period (circa 1 hour), the irradiated material will not grow on subsequent transplantation. This line of experimental work has here been extended to Jensen's rat sarcoma, the initial material for which was kindly provided by the Imperial Cancer Research Fund. From several points of view this tumour provides excellent material for the investigations in question. Inoculatious are successful in practically 100 per cent., for out of 125 inoculations into normal rats, 124 gave growing tumours; the rate of growth is rapid, tumours measuring 2 x 2 cm. frequently being obtained in 15 days after the inoculation of 01 c. c. of tumour emulsion. spontaneous absorption of the tumours however, is not uncommon; live disappearances have occurred in 53 rats, all of which were under observation for a minimum period of 20 days.