SN 
with Alkaline and other Bases. 185 
caused a fragment of phosphorus placed upon the foil to ignite. 
6. Anhydrous baryta, strontia and magnesia gave no reaction 
with the carbonic acid. Their hydrates all produced heat, slightly 
less perhaps than that evolved by hydrate of lime. 
’. It might have been anticipated that the reaction of the al- 
kaline earths with solid carbonic acid, would be more energetic 
than that of the alkalies from their habitudes in solution. But 
the decisive fact of the superior affinity of the alkalies for car- 
bonic acid in the dry state, would lead us to infer that the result 
in solution is due to the “influence of insolubility” in the pre- 
cipitated carbonates of the alkaline earths. 
t seemed desirable to extend the inference that carbonic 
acid does not combine directly with an anhydrous base. Potas- 
sium was therefore cut into thin layers and allowed to oxydate in 
the air. From the great disposition however of solid carbonic 
acid to condense moisture on itself, and the liability of the min- 
gled potash and potassium to ignite spontaneously or by slight 
causes, no accurate result could be obtained. 'There was no evi- 
dence of the production of heat by any reaction with the car- 
onic acid. 
9. The anhydrous protoxyds of lead, zinc and copper were 
subjected to solid carbonic acid placed upon cotton. No eleva- 
tion of temperature could be detected. The hydrates of these 
oxyds, when wrapped in cotton with carbonic acid and compress- 
ed by the fingers, gave a doubtful result to the sensation, the tem- 
n exposed to the gaseous ammonia, it may be remarked, was 
ed to burn more slowly and with a red flame. 
