“(70 ) 
ON THE 
REFRACTIVE POWERS 
MURIATIC ACID AND WATER, 
separate, and in a state of mixture. 
MR. HENRY CREIGHTON. 
Communicated by Mr. Ewart. 
(Read Feb. 18, 1814.) 
Iw the years 1808 and 9, being engaged with 
some experiments upon the application of 
different fluids to the formation of compound 
lenses, for correcting the aberration arising 
from the refrangible properties, of the rays 
of light, and being led by Dr. Blair’s enqui- 
ries on that subject (detailed in the Edin- 
burgh Transactions), to notice particularly the 
effects of muriatic acid and its compounds, 
some rather unexpected results occurred, not 
altogether connected with the above subject. 
These I take the present opportunity of de- 
tailing, and their tendency. is to shew, that 
rays of light passing through lenses of muriatic’ 
acid, are so refracted that the focal distan- 
ces of the lenses are proportional to the spe- 
cific gravity of the acid, &c. forming the lens. 
