A NEW PROCESS IN EUDIOMETRY. 
295 
Many success! ve experiments having shown us that this test, 
acting in a limited volume of air, in a very short time com- 
pletes the total absorption of the oxygen contained in it, 
leaving the nitrogen free, we were induced to think of the 
application of this property to the analysis of the air; and 
the result has been what we expected. 
The application of this new method is extremely simple, 
and it requires the employment of no peculiar apparatus. 
A common graduated tube 14 to 15 centimetres in length, 
and 12 millimetres in diameter, and a small phial with a 
ground glass stopper, containing 30 to 35 cubic centimetres, 
are the only vessels necessary. 
The process consists in introducing into the phial from 3 
to 4 grammes of copper turnings, then pouring in distilled 
water until the phial is half full, and afterwards filling it 
with a concentrated solution of ammonia. The bottle, thus 
completely filled, is closed with its glass stopper, and invert- 
ed in the water trough, taking care that the copper turn- 
ings do not rest on the orifice of the bottle. This first dispo- 
sition being arranged, you measure a volume of air in the 
graduated tube filled with water, and by means of a small 
glass funnel it is passed into the bottle, which has been un- 
corked under water. This being done, the mouth of the 
bottle is immediately closed, and it is taken out of the 
pneumatic trough, and shaken incessantly for eight or ten 
minutes. In less than a minute or two the ammonia is seen 
to assume a bluish tinge, which becomes gradually darker, 
as the ammoniuret of deutoxide of copper is formed. This 
blue tint assumes its maximum of intensity when you 
operate on from 15 to 20 cubic centimetres of air, it then 
becomes gradually fainter, when all the oxygen of the 
volume of air on which you operate has been absorbed ; 
this gradual loss of color, which points out the close of the 
operation, is due to the action of the copper, in excess, on 
the ammoniuret of the deutoxide, which is converted into 
colorless ammoniuret of protoxide. 
