390 G. F. Barker on normal and derived Acids. 
sodic mono-meta-sulphite, ea (4 i O, rubidic trismeta-per- 
chlorate, ete. 
With the knowledge of. the constitution of the acids above 
given, it may be interesting to examine the various groups 0: 
acid-forming or negative radicals, to see how far they conform 
meta acids of chlorine are given in the table, page 388. Of these, 
those in italics, all of which are monobasic, are known with cer- 
tainty, though polybasic acids of chlorine have been supposed, 
on experimental grounds, to exist.* In the case of iodine, how- 
} O,, and di-meta- 
3 
iodic acid HIO, or 10.) O are known; so also are mono- 
ever, mono-meta-iodic acid H,I0,, or ae 
groups. It may form 
: Hezad. 
Dyad. Tetrad. 
Ortho-hyposulphurous H,SO,. sulphurous H,SO,. sulphuric Hose 
meta H,S0, HAS" s 
cheese a” 
We ek eee H,SO, 
| The three dibasic acids above given are the ordinary 00 ‘i 
But the two hydrates of sulphuric acid, so called, correspon 
we , H,SO,; and from these are obtained similar 
tron group are similar to those of “hexad sulphur, the ees 
form being the more common; as in H Cro, ,H,Mn0,, a0 
chromate Pb’. ¢ 
