on the salts usually called hyper-oxy muriates, &c. 219 
gene ) is a strong acid ; and according to the relation above 
stated, it ought not to lose its acid powers by the addition of 
six proportions of oxygene. Till a pure combination of chlo- 
rine and oxygene is obtained, possessed of acid properties, 
we have no right to say that chlorine is capable of being 
acidified by oxygene, and that an acid compound exists in the 
hyper-oxymuriates. We know that chlorine is capable of 
being converted into an acid by hydrogene, and, as l men- 
tioned in my last paper, where this principle exists its energies 
ought not to be overlooked ; and all the new facts confirm an 
opinion which I have more than once before submitted to the 
consideration of the Society, namely, that acidity does not 
depend upon any peculiar elementary substance, but upon 
peculiar combinations of various substances. 
Rome, Feb. 15, 1815. 
Note. 
Since my return to England, I have made some farther investigations on oxyiodine, 
on the oxyiodes, and on the deep yellow gas. The portable apparatus which I 
employed in Italy, enabled me to operate only on very minute quantities of oxyiodine ; 
I have lately made my experiments on a larger scale. 
Thirteen grains of oxyiodine decomposed by heat, afforded 9.25 cubical inches of 
oxygene : and 48 grains of oxypotassame or oxyiode of potassium, yielded when de- 
composed by heat, 31 cubical inches of oxygene gas : and 30 g ains of potassame or 
iode of potassium (a portion of the salt so decomposed,) afforded by treatment with 
nitric acid 17.8 grains of dry nitre. These results give the number 246 as the num- 
ber representing iodine, and prove that oxyiodine consists of one proportion of iodine 
and five of oxygene ; and that the oxyiodes contain six proportions of oxygene 
The deep yellow gas when mixed with chlorine in the proportion of 2 to 3, or even 
of 2 to 2, deprives it of the power of acting upon Dutch foil, though . of chlorine 
when mixed with 2 of common air, still burns this substance. Hence if appears pro- 
bable, that the deep coloured gas and chlorine have a chemical action on each other, 
and that euchlorine is not a simple mixture of them. I hope soon to be able to pre- 
sent to the Society, some new results on this subject. 
London, June 12, 1815. 
£* 
r 1 2 
