19 
This experiment was often made in different ways, 
but without obtaining any combination with sulphuric 
acid. 
To another poi'tion of this resin fuming nitric acid 
was added, and heated carefully in the water bath. 
Soon a violent reaction took place, red fumes of nitrous 
acid were given out in large quantity. After the action 
of the nitric acid was finished, the whole was eva¬ 
porated to one third its volume, and water added, 
causing a white precipitate. This was thrown on to a 
filter, washed out, and dissolved in alcohol and ether. 
The reddish solution was boiled with animal carbon to 
decolorise it, and then exposed to a temperature several 
degrees below 0 0 C. But instead of crystals being formed, 
an oily substance, which probably holds nitrous acid, 
was sent down as the ether evaporated. 
The filtrate of the precipitate caused by the action 
of water on the nitric acid solution, was evaporated to 
dryness over the water bath, and the residue dissolved 
in a little water. 
To one portion of this ammonia and chloride of 
calcium were added, giving a precipitate of oxalate of 
lime. 
To another portion ammonia and chloride of ba¬ 
rium were added, giving a precipitate of oxalate of 
baryta. 
With another part ammonia and a solution of sul¬ 
phate of lime gave also a precipitate of oxalate of lime. 
Showing that oxalic acid is one of the products formed 
by the action of nitric acid on this resin. 
