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A NEW PROCESS IN ETJDIOMETRV. 
ART. LXXXII — A NEW PROCESS IN EUDIOMETRY FOR 
CALCULATING THE VOLUME OF THE ELEMENTS OF 
ATMOSPHERIC AIR IN RELATION TO EACH OTHER. 
By M. Lassaigne. 
Since the discovery of the component parts of the air, 
many methods have been employed by chemists to discover 
the relative volume of the constituent parts of this elastic 
fluid. The processes generally resorted to in laboratories, are 
all founded on the absorption of oxygen by various simple 
and compound bodies, whether at the ordinary temperature 
of the air, or by exciting the action, by caloric or electri- 
city. In this manner the solution of sulphuret of potassium 
was formerly used, and afterwards phosphorus, hydrogen, 
and the binoxide of nitrogen have been employed, and of 
late years the proto-sulphate of iron, decomposed by potas- 
sium, has been recommended. 
Dumas and Boussingault, by submitting air to the action 
of copper in a state of division, and heated to a dull red 
heat,'has latterly produced an important modification which 
enables us to estimate, by weight, the oxygen and nitrogen 
which exist in the air, instead of calculating the volume of 
each of these gases, as was the case in old eudiometrical ex- 
periments. 
In performing experiments, latterly, with protosulphate 
of iron, according to the directions of M. Dupasquier, and 
repeating the process he pointed out and published, we 
were led to adopt a test well known to chemists, but which, 
so far as we know, has never been applied to the analysis 
of air. 
This method is founded on the readiness with which 
copper divided into thin tables becomes oxidised in con- 
tact with air, in the presence of liquid ammonia, and on 
the formation of a blue ammoniuretof deutoxide of copper. 
