NEW MODE OF CHEMICAL ANALYSIS. 
39 
ART. VIII. — DESCRIPTION OF A NEW MODE OF CHEMI- 
CAL ANALYSIS. By M. Ebelman. 
No one has as yet endeavored to ascertain directly, in analy- 
sis, the quantity of oxygen which many metallic compounds 
absorb, while dissolving in the oxidating acid usually em- 
ployed, such as the nitric or nitromuriatic acids. This is owing 
to the difficulty experienced in estimating exactly, the oxi- 
dating value of the acid used, and likewise the variable 
composition of the gas which is disengaged during the reac- 
tion. If it is known beforehand, what quantity of oxygen 
the solvent used will yield, and if we ascertain the quantity 
disengaged, it is evident, that the difference will be the exact 
proportion which has been absorbed by the metallic com- 
pound during solution. The process which I am about to 
describe, appears to me to fulfil these two conditions. 
It is known that the hydrochloric acid in dissolving the 
oxide of manganese disengages one equivalent of chlorine for 
every equivalent of oxygen which the oxide will yield in 
passing to the state of protoxide. It is also known that this 
mixture will act upon the same metallic compounds, as the 
aqua regia with an excess of hydrochloric acid. If, then, we 
mix the body to be analysed with a determinate weight of 
oxide of manganese, of which the composition is previously 
known, treat the mixture with pure hydrochloric acid, ascer- 
tain the quantity of chlorine disengaged, and deduct it from 
that which the oxide of manganese should itself yield, the 
difference will be the quantity absorbed, and consequently its 
equivalent in oxygen. 
The estimation of the quantity of chlorine disengaged, may 
be made by the different methods already employed in lire 
analysis of manganesian minerals. Thus the chlorine gas 
may be collected, or, what is better, may be caused to react 
upon an aqueous solution of ammonia, and the resulting nitro- 
gen gas measured, which will be one-third of the volume of the 
chlorine produced. But the use of pneumatic methods are 
