i 24 Account of a new Eudiometer. 



nppearance, which oa the second in']ection is washed dmvu 

 insoluble in the hquor. ' About SO parts from 100 of ga5 

 ire absorbed. 



Nitrons gas is also absorbed by nitrate of copper in solu- 

 tion, without any peculiar alteration. 



In these experiments great care must be taken not to in- 

 crease the temperature of the gas by the hand. To prevent 

 this, I use a j^air of small oircular-mouihed forceps, lined 

 with cloth, which lirriilv grasp the measure, fio;. 3 ; and if 

 the experiments should in any way be delayed, a corre- 

 sponding manometer will always be sufficient to correct the 

 error occasioned by change of atmospheric temperature and 

 pressure. 



To ascertuiin the quantity of carbonic acid gas contained 

 in oxygen gas (of a known purity) after combustion or de- 

 composition of carbonaceous substances, lime water will be 

 found sufficient. 



If it is required to know the puritv of the oxvgen gas after 

 the carbonic acid gas has been absorbed, the best method 

 and the least liable to error, is to withdraw the residual oxy- 

 gen gas by means of the small graduated tube before de- 

 scribed. 



To do this, remove the measure into the small cistcirn of 

 mercury; press the quicksilver out of the small bottle by 

 the fingers and thumb, and let the tube rise a sufficient 

 height within the measure, that the bottle, extending itself^ 

 shall withdraw the whole of the gas from the measure, 

 taking care that the cock be stopped as soon as it has com- 

 pleted it, and also to prevent the solution from entering the 

 lube. 



If tlie opening of the tube is small, it may then be drawn 

 down into the mercury, without the possibility of any por- 

 tion of the gas escaping, while the measure is dried or 

 cleaned, or a fresh one lilled with mercury supplied to re- 

 ceive it. 



This way of transferring will be found very advantageous, 

 particularly in ihe separation of gases, liable to be absorbed 

 under certain temperaiures, and also where a new series of 



rc-nsents 



