74 
Transactions of the Royal Society of South Africa. 
have A 421 -f- 0*468 = A 900 : from dioxyxanthhydrol and the fluoresceins 
rather less : the average is A 898. 
The final triumph of the scheme comes when it is found that the wave- 
lengths of the seven singly-linked substances are themselves related to a 
fundamental constant (about 1380) by means of the factors contained in 
themselves : 
Dioxy-phenyl ether, A 1230, divided by the /0\factor 0"891, gives 1382. 
Dioxy-diphenylamine, A 1083, divided by the /NH\ factor 078, gives 
1388. 
Dioxy-diphenylmethane, A 898, divided by the /CH 3 \ factor 065, gives 
1382. 
Dioxy-benzhydi-ol, A 539, divided by the /CHOH\ factor 0 39, gives 
1381. 
Indophenol, A 650, divided by the /NOH\ factor 0 47, gives 1383. 
Dioxy-phenylsulphide, A 1258, divided by the /S\ factor 0*92, gives 1370. 
Dioxy-benzophenone, A about 323, divided by the /CO\ factor 0 234, 
gives 1380. 
This makes it almost certain that the unobserved ones have really the 
absorption-bands in the infra-red calculated in this paper. 
* 
