186 Intelligence and Miscellames. 
air, exhibiting a voluminous yellow ame. ‘The reason why, 
in common cases, it appears nearly uninflammable, is, that 
itis used in very small quantities, and in narrow vessels, in- 
to which the common air can,at the moment,scarcely enter, 
and the gas is not sufficiently inflammable to burn (like 
pure hydrogen,) merely at the surface of contact, at the 
mouth of the vessel. But if it rise through the air suddenly, 
in large volumes, and in its ascent, strike the flame of a 
candle, it is then sufficiently inflammable to be seen through 
a large room, and forms a handsome experiment.—Editor. 
9. Crystalization of Sulphuric Acid. 
It is very well known to every chemist, that sulphuric 
acid, diluted to about 1780. water being 1000. readily con- 
eals and crystalizes with a moderate cold. It is also well 
known that this crystalization, when the acid is not fully 
concentrated, often happens spontaneously, and it is aie 
that even carboys of sulphuric acid have been broken by 
the expansion, resulting from the crystalization. 
- Having occasion, recently, to clean out a neglected car- 
boy, which had been nearly emptied of its sulphuric acid, 
we found a few cubic inches of liquid in the bottom of the 
eucbodiand on shaking it,to wash out the adhering sulphat of 
‘ie eee eee * y we 
Me _ taped wes dil sur- 
prised by the rattling, produced by thirty or forty distinct crys- 
tals of great size and firmness. On being withdrawn from t 
vessel, they proved to be isolated crystals of sulphuric acid; 
some of them were two inches in the greatest diameter; 
they appeared as firm as crystals of alum—were white an 
transparent, and their form,which, on account of their cor- 
rosiveness and their rapid deliquescence, it was difficult te 
examine, appeared to be that of very obtuse and flat rhom- 
boids, like the lenticular crystals of calc spar—the téte de 
clou of the French. 
It is evident, in this case, that the little acid remaining in 
the open carboy, had attracted water enough from the air, 
to bring it to the degree of dilution, which makes it crystal- 
ize most readily, and that the moderate cold which it ex- 
perienced in a garret, ina mild night in November, ha 
been sufficient to produce that result in the manner above 
stated. —Lditor. 
