RECENT ADVANCES IN RADIOLOGY 193 



it exists in some beryls from which radium is absent. More recently 

 Mr. A. Piutti*'^ has examined 26 glucinum minerals which were not radio- 

 active, though they contained helium. The amount of this gas varied in 

 the same locality and appeared to bear no relation to the age of the 

 crystals. Helium also occurs in large quantities in mineral springs. 

 Messrs. Charles Moureu and A. Lepape found that the Carnot spring at 

 Santenay (Cote-d^Or) gives out no less than 17,845 liters of helium an- 

 nually.'^'' Now, according to Eutherford,^® 1 gram of radium in radio- 

 active equilibrium yields 158 cubic millimeters of helium annually. It 

 follows that if the helium of this spring is set free by radium there must 

 be present no less than 113,000 kilograms of radium. The Cesar spring 

 at Nevis (Allier) yields far more helium — 33,990 liters a year. The 

 French physicists conclude with ample reason that this helium is "fossil," 

 or that it has been stored up for an indefinite time and is not a nascent 

 product of radioactivity. 



All attempts to determine age by radiological methods assume that the 

 radioactive constant. A, is truly constant and finite; but, although no one 

 has yet succeeded in proving its variability, there are very serious doubts 

 about the matter. From the dawn of science philosophical investigators 

 have had in mind something corresponding to Eoger Bacon's protyl or 

 Kant's Urstofi:. Lavoisier was well aware of the existence of organic 

 radicles, gi-oups of atoms known to be composite, but behaving like ele- 

 ments. Ammonium and cyanogen are familiar inorganic examples of 

 complex bodies which take the place of supposedly elemental substances,- 

 while if complex substances may behave as elements, substances sup- 

 posedly elemental may be complex. The protylic idea underlay Front's 

 hypothesis and Mendeleef's periodic table; Dmnas also boldly asserted 

 his belief in the transmutability of the so-called elements. Astronomical 

 "observations indicate an increasing complexity in composition during the 

 evolution of stars. John Herschel thought that atoms bore the unmis- 

 takable stamp of a "manufactured article." In 1873 Mr, F. W. Clarke 

 suggested the evolution of one element from another. In 1904 Sir J. J. 

 Thomson asserted that as the universe gets older elements of higher and 

 higher atomic weight may be expected to appear. Finally, by showing 

 that many elements may be made to evolve helium and all elements 

 identical coi'puscles or electrons, the radiologists have prepared the way 

 for a greatly simplified conception of matter. 



Now, if there are any circumstances in which a radioactive substance 

 is stable, A must become zero; and if we could reproduce sueli circum- 



<»Attl. Accad. LIncel. vol. 22, part 1, 1913, p. 140. 



•"C'omptes Keudus, Purls, vol. 155, 1912, p. 107. 



"^ Had. substances and tbelr radiations, 1913, p. 5GU. 



