404 Miscellanies. 



ing is indeed forcibly felt, but the effect is chiefly confined to the • 

 epidermis. 



If gases have little effect in the production of cold, it is not so 

 with vapors, whose conductibility and capacity for heat are much 

 greater. I have therefore thought that if a permanent hquid, — 

 ether, for example — could be placed under the same condition of 

 expansibility as hquefied gases, we might obtain a frigorific effect 

 much greater than that procured by liquefied carbonic acid. To ac- 

 complish this, ether must be rendered explosible, and this I have 

 easily effected by mixing it with liquid carbonic acid. In this inti- 

 mate combination of the two liquids, which dissolve each other in 

 all proportions, ether ceases to be a permanent liquid under atmos- 

 pheric pressure ; it becomes expansible hke a liquefied gas, still pre- 

 serving its properties as a vapor-— viz. its conductibility and capacity 

 for caloric. 



The effects produced by a blowpipe fed by explosible ether are 

 remarkable : a few seconds are sufficient to congeal fifty grammes of 

 mercury in a glass capsule. If we expose a finger to the jet which 

 escapes from this veritable bloivpipe of frost, the sensation is quite 

 intolerable, and seems to extend much farther from the point of con- 

 tact than wi\h the liquid jet. 



I propose to replace ether by carburet of sulphur, which will in 

 all probability produce still more striking effects. — (Annales de 

 Chim. Decem.) 



5. Solidification of Carbonic Acid,* by M. Thilorier. — I had 

 the honor, at the last session, to state to the Academy the phenome- 

 na which accompany the liquefaction of carbonic acid gas : I now 

 announce the fact, important to science, of the solidification of this 

 gas. This first instance of a gas becoming solid and concrete, is so 

 much the more remarkable, as it relates to a gas which requires the 

 most powerful mechanical action to attain liquefaction, and which 

 resumes with greater rapidity its first form when the compression is 

 removed. 



Gaseous under the common temperature and pressure, and liquid 

 at zero, under a pressure of 36 atmospheres, carbonic acid becomes 

 solid at a temperature about the hundredth degree (Cent.) below 

 melting ice, and retains this new condition for several minutes in the 

 open air, and without the necessity of any compression. 



* Mentioned in the last No. of this Journal, p. 163, but the details are now given. 



