"Study of the cathode rays showed that they consisted of a stream of material particles, projected with great velocity, and possessing an apparent mass small compared with that of the hydrogen atom. The connection between the cathode [rays] and Röntgen rays [i.e., X rays] and the nature of the latter were also elucidated. Much of this admirable experimental work on the nature of the electric discharge has been done by Professor J.J. Thomson and his students in the Cavendish Laboratory Cambridge."
Radio-Activity is the fifth studio album by German electronic music band Kraftwerk, released in November 1975. The band's first entirely electronic album is also a concept album organized around the themes of radioactive decay and radio communication. Although the sleeves vary in language, sometimes with English song titles, and sometimes German, the music is always the same, with some lyrics in E
"Radium is extracted from pitchblende by the same process necessary to separate barium, to which it is very closely allied in chemical properties. ...The chloride of radium is less soluble than that of barium and can be separated from it by the method of fractional crystallization."
"Mme Curie has utilized the coloration of the crystals of radiferous barium as a means of controlling the final process of purification. The crystals of salts of radium and barium deposited from acid solutions are indistinguishable. The crystals of radiferous barium are at first colorless, but in the course of a few hours, become yellow, passing to orange and sometimes to a beautiful rose color. The rapidity of this coloration depends on the amount of barium present. Pure radium crystals do not color, or at any rate not as rapidly as those containing barium. The coloration is a maximum for a definite proportion of radium, and this fact can be utilized as a means of testing the amount of barium present. When the crystals are dissolved in water the coloration disappears."
"Both polonium and radium exist in infinitesimal quantities in pitchblende. In order to obtain a few decigrammes of very active radium, it is necessary to use several tons of pitchblende, or the residues obtained from the treatment of uranium minerals. ...M. and Mme Curie were indebted for their first working material to the Austrian government, who generously presented them with a ton of the treated residue of uranium materials, from the State manufactory."
"Since the preliminary announcement of the discovery of radium, Giese has devoted a great deal of attention to the separation of radium, polonium, and other active bodies from pitchblende. ...Using the method of fractional crystallization of the bromide instead of the chloride he has been able to prepare considerable quantities of pure radium. By this means the labor of final purification of radium has been much reduced. He states that six or eight crystallizations with the bromide are sufficient to almost completely free the radium from the barium."
"The polonium prepared by Mme Curie differs from the other radio-active bodies in several particulars. In the first place the radiations include only very easily absorbable rays. The two penetrating types of radiation given out by uranium, thorium, and radium are absent. In the second place the activity does not remain constant, but diminishes continuously with the time. Mme Curie found that the polonium lost half its original activity in the course of eleven months."
"I have found the theory that the atoms of the radio-active bodies are undergoing spontaneous disintegration extremely serviceable not only in correlating the known phenomena but also in suggesting new lines of research."