MIRACLES OF SCIENCE 



Parthenogenesis, natural and ar- 

 tificial, 145. 



Patton, Professor William, his 

 theory of the arachnid origin of 

 the vertebrate, 170. 



Patterson, Professor H., observes 

 the seeming formation of he- 

 lium and neon in the laboratory, 

 122. 



Pearson, Prof. Karl, his work* in 

 heredity, 199. 



Pendulum, used to test the mass 

 of the earth, 61. 



Perrine, Prof. C. D., discovers 

 two new moons of Jupiter, 13. 



Perseus, the new star in, and what 

 it revealed, 25. 



Pfeiffer, Prof. R., gave clue to 

 the vaccine method, 209. 



Pfund, Professor A. H., invents 

 a thermal couple more than 10 

 times as sensitive as the radiom- 

 eter, ill. 



Phoebe, the anomalous satellite of 

 Saturn, 10; revolves in reverse 

 direction; influence of this fact 

 on theory of world origins, 11. 



Photography, its great aid to the 

 astronomer, 37. 



Pickering, Professor W. H., dis- 

 covers Phoebe, a new satellite 

 of Saturn, 10. 



Pictures sent by wire and by wire- 

 less, 314. 



Plague, cattle, transmitted by 

 ticks, 245. 



Plague, the Asiatic, disseminated 

 by the house rat, 249. 



Plagues, banishing the, Chapter 

 VIII, 222. 



Planarian, the, used in biological 

 experiments to show the re- 

 generation of parts, 151. 



Planetoids, used by Sir David 

 Gill to determine the sun's dis- 

 tance, 77. 



Planetesimal theory, developed by 

 Professors) Chamberlin and 

 Moulton, 8 ; solves many puzzles, 

 14. 



Planets, how they are weighed, 

 81 ; the outer ones, except Mars, 

 far less dense than the earth, 

 no one of them being as dense 

 as the sun, 84; are they in- 

 habited, 85; the great outlying 

 ones are uninhabitable, 86. 



Pleiades, a group showing the pro- 

 cess of star formation, 22. 



Plumb line, used to test the mass 

 of the earth, 62. 



Plummer, Mr. H. C., independ- 

 ently discovered the two gi- 

 gantic star streams, 57. 



Police Court, its debt to the lab- 

 oratory, 159. 



Poynting, Professor J. H., made 

 delicate tests of the earth's mass 

 with the balance, 65. 



Proper motion of stars, how 

 tested, 41. 



Protozoal germs cause sleeping 

 sickness, 230; cause malaria and 

 other diseases, 244. 



Punnett, Prof. R. G., his illustra- 

 tion of Mendelian heredity, 194 ; 

 his Mendelian experiments with 

 the barnyard fowl, 197. 



Rabbits, used to develop test 

 fluids for determining blood 

 relationship, 161. 



Radiation pressure, its influence 

 on the movements of cosmic 

 particles, 51; see also "Light 

 pressure." 



Radiation, a new type of, 113. 



Radioactive substances, the alpha, 

 beta and gamma rays explained, 

 113. 



Radiopes, developed by Mr. Burke 

 in test tube with radium, 239. 



Radiometer, invented by Prof. 

 Crookes and perfected by Prof. 

 E. F. Nichols and G. F. Hull, 

 109; measures the pressure of 

 light, 110. 



Radium, discovered by Professor 

 and Madame Curie, 113; used 

 to count the atoms, 116 ; gives 

 off substance that becomes 



338 



