Krypton in the Scheme of Elements. 191 



supposing that the unknown formative cause has scattered 

 along its journey the groupings now called hydrogen, lithium, 

 glucinum, boron, carbon, nitrogen, oxygen, fluorine, sodium, 

 magnesium, aluminium, silicon, phosphorus, sulphur and chlor- 

 ine. But the swing of the pendulum is not arrested at the 

 end of the first round. It still proceeds on its journey, and 

 had the conditions remained constant, the next elementary 

 grouping generated would again be lithium, and the original 

 cycle would eternally reappear, producing again and again the 

 same fourteen elements. But the conditions are not quite the 

 same. Those represented by the two mutually rectangular 

 horizontal components of the motion (say chemical and electri- 

 cal energy) are not materially modified ; that to which the 

 vertical component corresponds has lessened, and so, instead 

 of lithium being repeated by lithium, the groupings which 

 form the commencement of the second cycle are not lithium, 

 but its lineal descendant, potassium. 



It is seen that each coil of the lemniscate track crosses the 

 neutral line at lower and lower points. This line is neutral as 

 to electricity, and neutral as to chemical actiou. Electro- 

 positive elements are generated on the northerly or retreating- 

 half of the swing, and electro-negative elements on the south- 

 erly or approaching half. Chemical atomicity is governed by 

 distance from the central point of neutrality; monatomic ele- 

 ments being one remove from it, diatomic elements two 

 removes, and so on. Paramagnetic elements congregate to the 

 left of the neutral line, and diamagnetic elements to the right. 

 With few exceptions, all the most metallic elements lie on the 

 north. 



Till recently chemists knew no element which had not more 

 or less marked chemical properties, but now by the researches 

 of Lord Rayleigh and Professor Ramsay, we are brought face 

 to face with a group of bodies with apparently no chemical 

 properties, forming an exception to the other chemical elements. 

 I venture to suggest that these elements, helium, argon, and 

 krypton in this scheme naturally fall into their places as they 

 stand on the neutral line. Helium, with an atomic weight of 

 1, fits into the neutral position between hydrogen and lithium. 

 Argon, with an atomic weight of about 10, as naturally falls 

 into the neutral position between chlorine and potassium. 

 While krypton with an atomic weight of about SO, will find a 

 place between bromine and rubidium. 



See how well the analogous elements follow one another in 

 order: C, Ti, and Zr; X and V; Gl, Ca, Sr, and Ba ; Li, K, 

 Rb, and Cs ; CI, Br, and I; S, Se, and Te ; Mg, Zn, Cd, and 

 Hg; P, As, Sb, and Bi ; Al, Ga, In, and Tl. ^The symmetry 

 of these series shows that we are on the right track. It also 

 shows how many missing elements are waiting for discovery, 



