Full text: Vol. II (2)

PROPERTIES OF THESE SALTS. 
449 
of potaſh or of soda. One part of this salt contains all the redundant 
oxygen that is furniſhed by six of oxy-muriatic acid. I may remark 
that the nitroſe acid, in its union with alkali, exhibits phenomena 
pretty similar. We obtain a true nitre, and a nitrous gas. 
The union of the ingredients of this oxy-muriat seems very flight. 
Exposition to the air ſeems to decompose the acid : For in a few days, 
or even hours, the falt changes to the ordinary salt of Sylvius. This 
decomposition happens more speedily in a watery solution of the ſalt; 
and we ſee a continual simmering on its surface, by the escape of mi 
nute bubbles of elastic matter. This is increased by exposure to the rays 
of the sun so as to be like an effervescence. This is vital air, of the purest 
kind. It would ſeem that the cauſtic alkali acts too powerfully on the baſis 
of the ordinary muriatic acid, and thus diminishes its attraction for the 
oxygen ; or the oxygen exists in it, perhaps, in a semi-elastic state. 
Mr. Berthollet also thinks that the vast abundance of water necessary 
for absorbing this gas prevents a closer union of the acid and alkali. 
He found that the combination could not be effected unless the solu 
tion of the alkaline falt be extremely diluted. If this liquor be eva 
porated, preserving it at the same time from the action of light, or the 
naked fire, it undergoes, at a particular period of the evaporation, a sud 
den change, by which the above salt is formed ; and that after this, 
neither the liquor, nor any of the salts which it affords by evapora 
tion, are possessed of the peculiar powers of the oxy-muriats. 
Mr. Scheele discovered in this oxygenated acid another most re 
markable property, namely, a power to deſtroy all vegetable and ani 
mal colours, and even those which are most permanent, prepared for 
the purposes of dying. It whitened or bleached vegetable substances 
in a surprising manner. Mr. Berthollet first thought of applying it to 
this use, and found that bees wax, brown linen yarn, and cloth, are 
bleached by it in a few hours or minutes, as effectually, and with as 
much safety to the staple of the goods, as if they had been exposed to 
the sun and air, with that intention, for as many weeks. 
VOL. II. 
3 L
	        
Waiting...

Note to user

Dear user,

In response to current developments in the web technology used by the Goobi viewer, the software no longer supports your browser.

Please use one of the following browsers to display this page correctly.

Thank you.

powered by Goobi viewer