Radium forms a series of salts analogous in appearance and chemical action to those of barium. In the course of time they become colored, especially if mixed barium salts. The radiations from radium produce marked chemical effects in a number of substances. Carbon dioxide is changed into carbon, oxygen, and carbon monoxide, and the latter is changed into carbon and oxygen. Ammonia is dissociated into nitrogen and hydrogen; hydrochloric acid into chlorine and hydrogen. Oxygen is condensed into ozone. In general, the action upon gases appears to be similar to that of the silent electric discharge. Water is decomposed into hydrogen and oxygen. If moist radium chloride or a salt of radium containing water of crystallization is sealed in a glass tube, the gradual accumulation of hydrogen and oxygen will burst the tube. The radiations rapidly decompose organic matter with the evolution of gases. Thus grease from stopcocks of apparatus used with radium or paraffin will give off carbon dioxide. Under an intense alpha radiation paraffin or vaseline become hard and infusible. White phosphorus is changed into red. The action upon living tissue is most noteworthy, as its possible use as a remedial agent is dependent upon this. A small amount of a radium salt enclosed in a glass tube will cause a serious burn on flesh exposed to it. It therefore has to be handled with care and undue exposure to the radiations must be avoided. Cancer sacs shrivel up and practically disappear under its action. Whether the destruction of whatever causes the cancer is complete is at least open to serious doubt. The coagulating effect upon globulin is interesting. When two solutions of globulin from ox serum are taken and acetic acid added to one while ammonia is added to the other, the opalescence in drops of the former is rapidly diminished on exposure to radium, showing a more complete solution, whereas the latter solution rapidly turns to a jelly and becomes opaque, indicating a greatly decreased solubility. Energy Evolved by Radium