oxygen with other bodies, is that of acrps. These are di ng 
by their sour, styptic taste; by their greater or less causticity : by 
their changing the vegetable colors to a red ; and by their combin- ae 
ing with the alkalies, earths, and metals, forming peculiar compounds ~ 
in. which the acid properties are totally lost. They are compounds 
of inflammable substances with oxygen, and this element derives its 
name from being the principle of acidity. CO 
Wath the same substance-oxygen is capable of combining in dif 
it proportions, so as to form different acids, the more powerful 
being generally formed by the larger proportion of oxygen. 
. Elecasaaclatare of the ie is Sense to express th facts. 
The name of each acid is derived from the substance of which, com- 
bined with oxygen, it is formed; and by a variation in termination, 
the different acids resulting from the different degrees of oxygena= 
tion of this base are denoted ; the name. of the more perfect acid 
terminating in the syllable ic, that of the one with the less proportion — 
of oxygen in ous. ‘Thus sulphur, with two proportions of oxygen, 
forms sulphureous and sulphuric acids, wtF 5 
__ Acids have a great tendency to combination. From this, and 
from the faeility with which they are in general decomposed and part 
With oxygen, they are most active of any of the compound chemical 
agents, and are used in many pharmaceutic operations. Po 
Lastly, oxygen unites with many bodies without rendering them 
acid ; it then. forms an order of bodies termed oxyps, It in geveral 
communicates to them a greater tendency to combination. To this 
order belong almost all the compounds it forms with the metals, and 
the greater number of vegetable and animal products. ie 
# 
- The second of the simple gases is azor. Like oxygen, when 
“pure, it exists always in the gaseous form, forming azotic gas. Thi 
gas, with less than one-fourth part of oxygen, constitutes the commoD 
atmospheric air. It possesses noremarkable property by which it may — 
be characterized, and thérefore it is rather distinguished by its negar 
tive qualities. It is lighter than atmospheric air, its specific gravity, — 
compared with it, being as 985 to 1000; it is unable to support com- 
istion Or respiration ; it is not absorbed by water, at least in any 
considerable quantity ; and it is not inflammable in the strict sense 
of the term, for although it combines with oxygen, yet the combi- 
nation is not sudden, nor is it attended with the emission: of fight, 
and with scarcely en of caloric. | wd e 
Azor combined with oxygen, in proportions in which these tv 
elements are mutually pee Ae forms a powerful acid, the Nitric. 
with a smaller propertion of oxygen it forms the nitrous acid. 
