ifie Sulphureous Add. 3 1 c 



boiling. Tliis acid freezes at a few degrees belovv zero, or the freezing point of water ; 

 and what may appear alloniniing is, that not the fmallell portion of gas is difengaged, as 

 happens v.hen the other gafes arc diiTolved in water. 



Thefe experiments prove, 1. That the colder the water the more it abforbs of fulphureous 

 acid. 2. That t!ie combination of thefe bodies is accompanied with heat. 3. That fuch a 

 combination cannot preferve at a more elevated temperature all the acid it was charged 

 with at a lower degree of heat. 4. That this combination pailes to the folid flate by cooling, 

 without undergoing decompofition ; a fadt which fhews a great aflinity of water for the 

 fulphureous acid, and a weak attraftion of this lad for caloric. 



V. AcJion of Adds iipcn ihf Sulphiireous /Idd. 



ASion ofibi Stilpbiiric Arid.] We caufed fulphureous acid gas to pafs through tha fulphu- 

 ric acid cooled by a mixture of ice and fait, in proportion as the acid gas was extric.ited, 

 it combined with the fulphuric acid without one fingie bubble arriving at the upper part. 

 tsoon afterwards the whole of the acid became congealed ; notwithftanding which the com- 

 bination continued to be made. 



From time to time^ the tube through which Jie fulphureous acid pafled was obftrufled, 

 and required to be withdrawn out of the fluid. By this treatment the matter flowed, and 

 a quantity of gas was difengaged in the form of bubbles. The folid combination had no very 

 perceptible fmell while it retained the form of ice ; but when a portion was taken out, and 

 laid upon a plate of glafs, it exhibited an elTervefcence like that of marble when an acid ii 

 poured on it, and foon afterwards it became liquid and very odorant. 



When the temperature of the mixture of fait and ice had rifen to the freezing-water point, 

 part of the folid mafs became liquid, and bubbles were formed which rofe up in the empty 

 part of the vafe ; but as this was exadly clofed, they cryftallized on the fides in the form of 

 the leaves of fern. 



Aftkn of the Nitric Acid-Z The fulphureous acid decompofes the nitric acid, particularly 

 ti'hen this laft is in a concentrated ftaie. The fluid immediately becomes red, and foon after- 

 wards hot, with a difengagement of nitrous gas frequently mixed with a fmall quantity of 

 fulphureous acid. The fulphureous acid is changed by this operation into fulphuric acid, for 

 it abundantly precipitates the muriate of barytes. Hence it is proved, that the fulphureous 

 acid has more affinity with oxygene than the nitrous oxide. This truth is confirmed by the 

 converfion of fulpliur into fulphuric acid by means of the nitric acid. 



A^iori of the Oxygf'untal A/iirintic Add.'} If the oxygenated muriatic acid gas and tlie 

 fulphureous acid gas be brought into conta(f!V, white fumes are afl'orded ; the two gafes 

 become immediately liquid, and Jofe their odcur, if they have been employed in fuitable 

 proportions. The f:imc cffccls take place when thefe tft^o acids are mixed together in the 

 liquid ftate, namely, tlie lofs of odour and colour. From the acflion of thefc tvi-o bodies on 

 each other, fulphuric acid and common muriatic acid arc produced. The theory of this 

 operation is nearly tlie fame as that of the preceding experiment. 



VI. Anion of cimhuJiibU Bodies on the Sulphiinoiis Add. 

 Tlie Action of Hydrogene.] Thefc two fublhnces liave no mutual adion In the cold j but 

 if they be palR-d through a tube of glafs or porcclainc well heated, in the proportion of 

 three parts by mcafurc of hydrogcnc gas and one part of fulpliurcous acid gas, the latter is 



S f 2 dccompofed. 



