ACCOUNT OF A tf£W EUDIOMETER. £3 



•f silver, and acetite of lead, of a dark. brown colour, and 

 would be useful as chemical reagents. 



Carbonic acid gas, as 1 have before stated, decomposes so- 

 lutions of the acetite of lead, hot or cold, forming a precipi- 

 tate of carbonate of lead. 



Carbonic acid gas is absorbed by the solution of the green Carbonic acid 

 sulphate of iron, under the temperature of 100° Fahren- S a = absorbed 

 ■ • i i • it • f i /> i on 'y hy the 



heit: but this is only the action or the water or solution. water in solu _ 



If the temperature be near boiling, or above 180° Fahren- tion of sul- 



heit, the solution increases the volume of the gas without 



the slightest absorption ; after carbonic acid gas has in this 



way been treated with the hot solutions, it is still soluble in 



water at the common temperature, or in aqueous solutions 



of lime, or alkali. 



Nitrous gas is absorbed by solution of sulphuret of pot- Ni trous ga S . 

 ash, with a separation or formation of sulphur. Upon inject- 

 ing the solution the sides of the measure take a milky ap- 

 pearance, which on the second injection is washed down, in- 

 soluble in the liquor. About 80 parts from 100 of gas are 

 absorbed. 



Nitrous 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- Forceps used 



crease the temperature of the gas by the hand. To prevent to P revent to- 



i-r c n-i ito -.•! crease ©f tem- 



tlus 1 use a pair or small circular-mouthed forceps, lined pw - a ture from 



with cloth, which firmly grasp the measure, fig. 5 ; and if the hand, 

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

 ing manometer will always be. sufficient to correct the errour 

 occasioned by change of atmospheric temperature and pres- 

 sure. 



To ascertain the quantity of carbonic acid gas, contained Examination 

 in oxigen gas (of a known purity,) after combustion, or de- of oxi S en *° r 

 composition of carbonaceous substances, lime water will be a f ter C ombu*. 

 found sufficient. tion, 



If it is required to know the purity of the oxigen gas, af- an( j f or ot j ier 

 ter the carbonic acid gas has been absorbed, the best method, gasse*. 

 and the least liable to errour, is to withdraw the residual oxi- 

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

 scribed. 



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



mercury : 



