on the Newry pitch-stone, &c. 323 
nitric acid. When dry, the soluble part was taken up by 
water and replaced by fresh acid. This process was repeated 
until the acid seemed to have no farther effect. The aqueous 
solutions were then thrown together and evaporated to dry- 
ness. Alcohol removed the nitrate of lime ; and the iron 
being peroxidated by the nitric acid, nothing remained when 
the mass was re-dissolved in water but nitrate of soda, which 
crystallized in cubes, and had every other property of nitre. 
This being evaporated again to dryness, and weighed, was 
found to be 7,75 grains of nitrate of soda, which gives 2,857 
for soda. I consider this to be the real proportion of the 
alkali. It differs but little from the following result by 
Muriatic acid. 
100 grains were treated in the same way with muriatic 
acid, the iron being peroxidised when the aqueous solution 
was evaporated to dryness. The chloride of sodium weighed 
5 grains. Now, 5 grains of chloride of sodium make of dry 
soda, or oxide of sodium, 1,98198, being in the proportion 
55,5 t0 22 ; but 1,98198 of dry soda produce 2,87044 of 
hydrate of soda, the state in which it is probable the alkali 
exists in the stone. 
In the process with the muriatic acid two new and decisive 
phenomena presented themselves. 
When evaporating off the excess of muriatic acid from the 
solution in a platina crucible with a silver cover, I observed 
the inside of the cover, which I had laid lightly on and re- 
moved from time to time, to be coated with a yellow substance, 
which had a bituminous smell. I placed the cover with the 
