176 PROPERTIES OF THE RADIATIONS [cH. 
panied by the emanation, but no new lines were observed in its 
spectrum. Giesel’ has observed a similar evolution of gas from 
solutions of radium bromide. Giesel forwarded some active material 
to Runge and Bodlander, in order that they might test the gas 
spectroscopically. From 1 gram of a 5 per cent. radium prepara- 
tion they obtained 3°5 cc. of gas in 16 days. This gas was found, 
however, to be mainly hydrogen, with 12 per cent. of oxygen. In 
later experiments Ramsay and Soddy? found that 50 milligrams of 
radium bromide evolved gases at the rate of about 0°5 cc. per day. 
This is a rate of evolution about twice that observed by Runge and 
Bodlander. On analysing the gases about 28°9 per cent. was found 
to consist of oxygen, and the rest was hydrogen. The slight excess 
ot hydrogen over that attained in the decomposition of water, they 
consider to be due to the action of oxygen on the grease of the 
stop-cocks. The radio-active emanation from radium has a strong 
oxidizing action and rapidly produces carbon dioxide, if carbonaceous 
matter is present. The production of gas is probably due to the 
action of the radiations in decomposing water. The amount of 
energy required to produce the rate of decomposition observed by 
Ramsay and Soddy—about 10 cc. per day for 1 gram of radium 
bromide—corresponds to about 30 gram-calories per day. This 
amount of energy is about two per cent. of the total energy emitted 
in the form of heat. 
Ramsay and Soddy (doc. cit.) have also observed the presence of 
helium in the gases evolved by solution of radium bromide. This 
important result is considered in detail in section 201. 
Physiological actions. 
117. Walkhotf first observed that radium rays produce burns 
of much the same character as those caused by Rontgen rays. 
Experiments in this direction have been made by Giesel, Curie and 
Becquerel, and others, with very similar results. There is at first 
a painful irritation, then inflammation sets in, which lasts from 10 
to 20 days. This effect is produced by all preparations of radium, 
and appears to be due mainly to the @ and 8 rays. 
1 Ber. d. d. Chem. Ges. 35, p. 3605, 1902. 
* Proc. Roy. Soc. 72, p. 204, 1903. 
