92 Sir H. Davy on a new Substance 
represent the combination of chlorine, as argentana the proto- 
chloride of silver; and I'm this system may represent fluorine. 
Thus calcala would be fluor spar, or one proportion of fluo- 
rine, and one of calcium, and the different combinations of 
calcium with the supporters of combustion with oxygen, 
fluorine, chlorine, and iodine in one proportion, would be thus 
expressed calca^ calcala, calcana, and calcama. 
I throw out these hints for discussion, rather than with any 
wish for their adoption, and for the purpose of directing the 
attention of chemists towards the subject of nomenclature, 
which ought to be settled on some fixed principles ; and in 
naming a new class of compounds, great caution should be 
used to prevent the necessity of alteration. 
In my last paper, presented to the Society two months ago, 
I ventured to suggest that it was probable, that new species 
of matter, which act with respect to inflammable bodies, like 
oxygen, chlorine, and fluorine, would be discovered. I had 
not hoped, at that time, to be able so soon to describe the pro- 
perties of a body of this kind, which forms an acid with h}^- 
drogen, like chlorine and fluorine, and which in some of its 
combinations resembles oxygen. 
This new fact wall, I hope, do something towards settling 
the opinion of chemists respecting the nature of acidity, which 
seems to depend upon peculiar combinations of matter, and 
not on any peculiar elementary principle. 
It is probable that iodine wall be found in many combinations 
in nature. We may expect that it wall be discovered in vari- 
ous marine vegetables, and in sea water, and probably the loss 
of weight indicated in the analysis of certain fossil substances 
may depend upon its expulsion. 
