34 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 65 



forces set up by the extraction of different numbers of magnetons 

 from the parent atom : I hope to discuss this in a somewhat quanti- 

 tative way, when dealing with the " retaining powers " of atoms for 

 magnetons (see §16). 



In this section the relations between analogous atoms in any group 

 of the Periodic Scheme have not been discussed : this also must be 

 postponed. 



§10. Molecules Containing the Negative Bond 



The more typical compounds of the elements have been briefly 

 classified in the last section : many compounds of less ordinary types 

 may be brought into the general scheme by means of the nega- 

 tive bond. As in the case of (cilfcl ), this is formed between those 

 atoms and groups only that are capable of negative action. Some 

 such are : ~xC\) , -f O7-H, -tN5 (which is for the most of the time 



in the other phase: see §9), t04- SO-foVrl ; and among their 

 binary compounds we have : 



(Cl+Cy, chlorine molecule ; 



(Cl+O-j-H , hypochlorous acid ; 



(CItNI , chloramide; 

 H -f Oy: Oy- H , hydrogen peroxide ; 

 H-^CHrN \ , hydroxylamine ; 



H \Ox5v~ ^®- i\P/ ^"' mono P ersu lp nur i c acid ; 



H-KH- SO,\Oj^Oj- SO.jK>rH, persulphuric acid. 



Molecules like these are liable to the same kind of tautomerism as 

 HC1, H 2 0, H 3 N molecules (§9), but it will be more complicated, for 



