the oxygenated muriatic Acid. 207 
of errors which might have taken place through a double 
affinity. I therefore made the following. experiments, in 
which I employed a decoction of cochineal in water, inftead 
of the acetite of indigo. 
Experiment VU. To half an ounce of the nivalis: 
miuriatic acid, a decoction of cochineal was added till the 
acid ceafed to act on its colour. It deftroyed the colour.of 
390 grains of the decoction. 
Experiment 1X. A repetition of Experiment vi1r1. The 
colour of 385 grains of the decoétion was deftroyed in this 
experiment. 
Experiment X. To half an ounce of the acid, 6 drops of 
the liquid alkali were added. This mixture deftroyed the 
colour of 315 grains of the decoétion. 
Experiment XI. Eight drops of the alkali were mixed 
with half an ounce of the acid. This mixture deftroyed the 
colour of 305 grains of the decoétion. . 
On a comparative view of the refults of thefe experiments, 
it will appear, that an addition of potafh to the bleaching 
liquor impairs its ftrength confiderably. This diminution of 
power, and the expence of potafh, are a ferious lofs in an 
extenfive manufacture. It would, therefore, be defirable to 
have an apparatus for the ufe of the pure oxygenated mu- 
riatic acid fimply diffolved in water, which is at once the 
cheapeft and beft vehicle for it. This apparatus muft be 
fimple in its conftruction, and obtainable at a moderate 
expence ; it muft confine the liquor in fuch a manner as to . 
prevent the efcape of the oxygenated muriatic acid gas, which 
is not only a lofs of power, but alfo an inconyenience to the 
workmen and dangerous to their health; and it muft, at 
the fame time, be fo contrived, that every part of the ftuff 
which is confined in it, fhall certainly and neceffarily be ex- 
pofed to the action of the liquor in regular fucceffion. Hay- 
ing invented an apparatus capable of fulfilling all thefe con- 
ditions, I have the pleafure of fubmitting a defcription of it 
to the Society, by means of the annexed drawing. 
DE- 
