49'i H. Davyds further Experiments 
afford oxygene and iodine. Individually they may be named 
from their bases. Thus oxy-potassame, or oxy-iode of potas- 
sium, will signify the triple compound of potassium, oxygene, 
and iodine, and oxy-barame, or oxy-iode of barium, will denote 
the triple compound of barium. 
2 . Some observations on Hydroionic Acid, and on the compounds 
procured by means of it. 
1 . I have generally procured the hydroionic acid which I 
have used in my experiments by the process referred to in the 
last section, the action of hydrophosphoric acid on potassame, 
but I have sometimes employed the gas procured from mois- 
tened iodine by phosphorus. 
The hydroionic acid gas is rapidly decomposed by being 
heated in contact with oxygene, and a solution of iodine and 
hydroionic gas in water is formed, and it is slowly decomposed 
by heat alone, affording a deep red-brown easily fusible sub- 
stance, which seems to be a compound of hydroionic gas and 
iodine. 
When condensed in water, it is instantly decomposed by 
solution of nitric acid and iodine precipitated. 
The solution of hydroionic acid rapidly absorbs oxygene 
from the air, and becomes yellow, and at last deep tawny 
orange ; and this absorption is assisted by light and heat, the 
hydrogene is attracted by the oxygene to form water, and the 
iodine formed is dissolved in the remaining acid. 
The concentrated hydroionic acid will probably form a good 
eudiometrical substance; it does not render the vessels in 
