Multiple Proportions of the Atomic Weights. 75 



multiple of 7. These formulae are given below, with the 

 old and new atomic weights ; the proportion of silicon to 

 oxygen being in the ratio of 7:8 in all the formulae. 



1. SiO =Si 7:0 8:: 7 



2. Si0 2 = SiU:0l6::7 



3. Si0 2 = Si28:032::7 



4. Si0 3 = Si21:024::7 



5. Si 2 O 5 = Si35:O40::7 



6. Si 2 5 = Si70 : 080 : : 7 : 8 



I have shown that the ordinal number of the typical 

 molecule determines the quantivalence of each series of 

 elements under it. When my paper was published in 1878, 

 the only member of the series H7/1 known to be heptavalent 

 was manganese, but I then stated that, the relation of this 

 element to the iron group indicated a much higher quanti- 

 valence for the other members of the series Hyn than had 

 hitherto been accorded to them. MM. Hautefeuille and 

 Chappuis have since formed pernitric acid, which indicates 

 a higher quantivalence for nitrogen than had previously been 

 obtained for this element ;* and more recently, MM. Debray 

 and Joly have shown that ruthenium is heptavalent by the 

 formation of the heptarutheniates of potassium and sodium, 

 which have many points of resemblance to the heptaman- 

 ganates.-f* 



One objection raised against the theory which I have 

 propounded on the origin and nature of the elements I will 

 remark upon, is an alleged want of causal connexion 

 between the series of planetary distances and a series of 

 atomic weights. Now, considering that specific gravities 

 and atomic weights are admittedly correlated properties of 

 the elements, and that specific gravities are fundamentally 

 correlated with the dimensional properties of space, it follows 

 that planetary condensations within interplanetary space,, 



Co?npies Rendus, tome XCIV., pp. nil, 1306, 1882. 

 + Ibid, tome CVL.pp. 1494, 1888. 



