10 



THE NEW YORK JOURNAL OF PHARMACY 



Radium compounds bring about chem- 

 ical decomposition and physiologically 

 affect vegetable and animal organisms. 

 Because of its decomposition thrcxigh 

 the constant giving off of the so-called 

 Alpha, Beta and Gamma rays, radium 

 salts spontaneously develop heat and in 

 consequence always show a slightly 

 higher temperature than the surround- 

 ing objects. 



It has been shown (by Ramsay & 

 Soddy) that the emanations from radium 

 bromide when collected, change, in a 

 few days, into the element helium. The 

 alpha rays are positively charged helium 

 atoms, shot out with about 1/15 tlie 

 velocity of light. The beta rays are 

 al)out one hundred times more penetrat- 

 ing than the alpha and consist of nega- 

 tively charged corpuscles, moving with 

 a velocity of the same order as that of 

 light. The gamma rays are from ten to 

 one hundred times more penetrating than 

 the beta. 



The emanations are given oft' very 

 slowly from the solid radium salts, but 

 when strongly heated or dissolved, the 

 emanations are given oft' quite freely. 



The period of radium emanation is 

 from three to four days and radium, 

 free from its emanations, will again 

 produce the equilibrium amount of 

 emanation, if sealed for about thirty 

 days. 



Pure radium free from its disinegra- 

 tion products, gives out only alpha rays, 

 but owing to the presence of these 

 products, radium salts ordinarily emit 

 all three types of radiation. 



The rate of disintegration of radium 

 corresponds to the transformation of 

 about thirty-five one-hundred-thou- 

 sandths of its mass per year and the time 



re(|uired for exactly half of any given 

 c|uantity to completely disintegrate into 

 other elements is about 2000 years. It 

 has been supposed that the final stable 

 form of matter ultimately attained after 

 the series of radio-active changes, is 

 ordinary lead. 



Radium emanation is a chemically 

 inert gas of the Argon type. It shows a 

 characteristic spectrum like radium and 

 when strongly cooled condenses at 

 150° C. In 191 1. R. W. Gray and Sir 

 W. Ramsay determined the atomic 

 weight of radium emanation by weigh- 

 ing a known volume of pure emanat'on ; 

 from their results, the atomic weight 

 was found to be 223. that of radium 

 being 226.4. They have suggested the 

 name ''Niton" (Greek for "the shining 

 one") for radium emanation. 



One of the properties of radium 

 emanation is to cause bodies which are 

 exposed to it. to become temporarily 

 radio-active. This effect is now known 

 to be the result of a deposit of radio- 

 active matter on inactive bodies ; this 

 matter being called the ''active deposit." 

 The source of this "active deposit" is 

 the gaseous radio-active emanations that 

 radium produces. The period of this 

 active deposit is 26.8 minutes. 



By means of a kinetic method, it was 

 established that radium emanations are 

 about three to four times as soluble in 

 the blood as in water under the same 

 temperature and pressure. 



The sources of radium are carnotite 

 ores and pitchblend. Carnotite was dis- 

 covered as early as 1887 by Charles 

 Poulot in Rock Creek district of Mont- 

 rose County, Colorado; it is composed 

 chieflv of uranium and vanadiiun min- 



