Atoms and Molecules. 895 



that if there is an isotope of mass 10 or 11 its existence is not established 

 by his investigation. A new model for Gl is shown in fig. 1 b, this 



being simply the octagon ring shown at Gl-2, fig. 1 with one of the 

 hydrogen atoms missing. The atomic number is four according to 

 rule and mass 2x4+1-008=9-008. 



The form shown for boron at B-2 fig. 1 gives mass 11 and atomic 

 number 5 according to rule, but it may be rejected because of its 

 unsymmetrical form, and also because boron probably contains hydrogen 

 as recently observed by Rutherford. The preferred form for boron 

 is the octagon ring Gl-2 of fig. 1 in which a single hydrogen atom is 

 inserted at the exact centre. This raises the mass from 10-016 to 

 11-024 and the atomic number from 4 to 5 according to rule. It supplies 

 an atom rich in hydrogen, containing three H-atoms, and is sym- 

 metrical. 



The atomic weight of boron has recently been revised from 11-0 

 down to 10*9 in the latest International Table since the work of Aston 

 on isotopes. It seems possible that the isotope of 10 found by 

 Aston may be the octagon form shown as Gl-2 fig. 1 having mass 

 10-016, which may enter the boron as an impurity. Its atomic number 

 is 4 rather than 5 and should be classed as Gl, though it is very similar 

 to the boron atom. 



Rutherford has recently obtained great range particles from B, N, F, 

 Na, Al, and P. He does not state that all of these particles are 

 hydrogen atoms. In the models of fig. 1 there is no hydrogen in F and 

 Na, but there are particles of mass 2| which must behave much like 

 hydrogen if they exist. If they carry a charge of 2 e when liberated from 

 the atom, the value of e/m would be 2/2^ as compared with that for 

 hydrogen 1/1-008, which would make it more difficult to distinguish 

 them from hydrogen than it would be if they carry but a single charge. 

 It seems important to ascertain experimentally whether or not all these 

 great range particles are hydrogen. 



The atoms of magnesium and aluminium may be added to the list 

 above given. There have been reported isotopes of magnesium havino- 

 masses 24, 25, and 26, the greater number having mass 24. This atom 

 may consist of an inner ring of two alpha-particles and four connectino- 



