192 Experiments to determine the [Skpt. 



The acid gas appears, in short, to possess very strong affinities, as 

 it displaces most other acids from their combinations, and is not 

 itself to be separated from alkalies and metallic oxides when once 

 united with them. 



It will be better to present under a tabular form the general 

 results of the action of different re-agents on the mixed, gas, as it 

 will occupy too much space to enumerate the particulars of each 

 experiment. 



Re-agents. 



Atmospheric 

 air 



Chlorine gas.. 



Nitrous gas.. . 

 Water 



Phosphorus . . 

 Potash 



Soda 



Ammonia. . . . 



Lime 



Barytes 



Bl-arboiiutc 

 of potash. . 



Effects. 



i 



{ 



{ 



After long standing, ex- ) 



ploded by electricity..../ 

 Immediate diminution of I 



volume to J 



The residuum contains 26-66 



per cent, that precipitates 



a-etate of lead white. 



White fumes 



Absorbs the whole of the 



arid gas 



White fumes, when heated, 



diminishes to 



Browni-ih black precipitate, I 



insoluble J 



Dito 



Velvety black precipitate, \ 



insoluble J 



Green precipitate, expan- I 



sion of volume to / 



Soluble combination 



Soluble compound 



Displaces carbonic acid,") 



and forms a brownish > 



solution J 



Change of 

 volume of 

 100 mea- 

 sures to 



S4-76 



88-00 

 01 



88-SS 



63-SS 

 6883 

 7575 



121 



6925 

 62-72 



None 



Hydrogen 



in the resi 



duum per 



cent. 



None 



None 

 45 18 



3611 



52-94 

 3S56 



None 



Hydrogen 

 in mixed 



gas em- 

 ployed per 

 cent. 



42-42 



27-55 

 30-9S 



36-44 

 29-21 



In the action of the mixed gas on metallic solutions some curious 

 effects will be observable, such as will sufficiently distinguish it from 

 sulphureted hydrogen. The latter, it is well known, does not preci- 

 pitate iron and nickel from their solutions ; but this acid gas will be 

 found to form insoluble compounds with those metals. The 

 appearance and colours of the precipitates differ in most cases from 

 those produced by sulphureted hydrogen. The amount of apparent 

 absorption will be seen to vary in the' different solutions, but these 

 anomalies will be made to disappear in the sequel. The great 

 distance of time at which many of them were made has in some 

 small degree influenced the results. The gaseous residues of all the 

 different trials were inflammable ; and I have to regret that want of 

 time prevented me from having ascertained the quantity of hydrogen 

 in each. 



