348 Liquefaction mid Solidification of Carbonic Acid. 



The force of its gasefaction is alleged to be equal to, but not 

 so sudden as, that of gunpowder. 



Th6 temperature at which the solidification took place was 

 presumed to be about — 148° F. ; although the experiments be- 

 fore the committee of the Academy shewed — 124°. 



Such is, in substance, the account by M. Thilorier of his novel 

 and curious discovery, reported in the Annates de Chimie. No 

 description of the method of procedure, or of the apparatus used, 

 is annexed ; and we are left to conjecture, and to the imperfect 

 description of travellers, for any farther knowledge of either. 



Having repeated the experiments of Thilorier, I deem it not 

 useless to subjoin a draught of the instrument with which, aided 

 by the suggestions of an intelligent pupil in France, and the as- 

 sistance of friends here, I was enabled successfully to repeat most 

 of the experiments of Thilorier, and to verify some, and correct 

 other, of his results. 



The apparatus consists of a generator of cast iron. A, supported 

 by a wooden stand, B, a receiver, F, also of cast iron, connected 

 to the generator by a brass tube, and fastened firmly to it by the 

 stirrup screw, K ; H, I, J, are stop-cocks, G, the nozzle of a pipe, 

 L, a glass level-gauge, and S, M, R, a pressure-gauge. 



The generator is 20 inches long and 6 inches in diameter ex- 

 teriorly. Its cavity is 16 inches deep, and 3 inches, nearly, in 

 diameter, so that it will hold about 4 pints. The walls are, of 

 course, about 1^ inches in thickness. At the top, an aperture of 

 two inches in diameter is closed by a strong wrought iron screw, 

 the shoulder of which is let in about a quarter of an inch. The 

 collar is of block tin, turned to the size of the shoulder of the 

 screw. There is a hole in the head of the screw E for the re- 

 ception of a long, strong iron bar. 



The copper cup, N, If inches wide, and 9 inches long, holds 

 about 12 fluid ounces. There is a little handle at the top, and a 

 copper wire at the bottom, which makes the whole length a little 

 less than that of the cavity of the generator. This cup is used 

 to introduce the sulphuric acid. 



The brass tube between the generator and receiver is divided 

 into two parts of equal length, which admit of being united by 

 means of a conical juncture, kept tight by the stirrup and screw, 

 K, K. Each of these portions of the tube may be closed or 

 opened at pleasure by a stop cock. One is placed at I, another 



