78 The Law of the Rhythmic Breath 



particles of negative electricity. It is paradoxi- 

 cal, yet true, that the physicist knows more about 

 these ultra-atomic corpuscles and can more easily 

 count them than is the case with the atom of 

 which they form the parts." 



Some of these corpuscles move at a speed of 

 200,000 miles a second, and the unscientific reader 

 will get a clearer idea of their minuteness if told 

 that the molecule, of which they are parts, is so 

 small as to be invisible even under the most power- 

 ful microscope. Sir William Thompson made 

 this graphic comparison : " If a drop of water as 

 large as a pea were magnified to the size of the 

 earth, the molecule would appear scarcely larger 

 than the original drop." 



Radium gives off three kinds of rays which have 

 been named respectively alpha, beta, and gamma. 

 The alpha rays are compared to the " ions," or 

 tiny particles, which fly from red-hot metals. 

 They are positively electrified, and the particles 

 are about twice the mass of the hydrogen atom. 

 These rays have a velocity of 20,000 miles a sec- 

 ond, and are constantly emitted from radium in 

 its natural state without perceptible loss to its sub- 

 stance any more than the exhalation of its odor 

 changes a flower. The beta rays are negatively 

 charged corpuscles, about one two-thousandth the 

 size of those making up the alpha rays; and, save 

 for their greater velocity circa 100,000 miles 



