Pneumatic Provision-Safe, — Artificial Co?igelatio?i. 389 



but after being some days exposed to tbe air, became entirely 

 free from it. The expense of water thus distilled is about the same 

 as that of water embarked ; but were it even greater, the many 

 obvious advantages attending a constant command of fresh water 

 at sea, are such as must supersede any consideration of this kind. 



PNEUMATIC PROVISION-SAFE. 



It is a well established principle, that three united agents con- 

 cur in the destruction of alimentary substances — air, heat, and 

 water; and that Isy neutralizing one of these agents the action 

 of the other two is paralysed. M. Foucque jun. of Paris is 

 said to have succeeded in effecting this, by producing a vacuum 

 in an apparatus simple, easily used, and not expensive. He has 

 made his apparatus of two sizes. One, which is intended to be 

 kept in the kitchen to receive the dishes to be preserved, is made 

 of a square piece of hard stone thirteen inches in diameter, in 

 this stone a circular groove is cut, and furnished with mastic 

 (or lute); a cast-metal bell is fitted into the groove, and a hole 

 is pierced in the top of the bell of one line in diameter. The 

 other safe consists of a large earthen pot of a thin consistence, 

 around the mouth of which a luted groove is cut, and a cast- 

 metal bell with a hole in the top fitted into it, in the same 

 iqanner as in the other safe. 



Wlien tlie substances which it is desired to preserve have been 

 placed in either of these safes, a little spunge is dipped into spirit 

 of wine of 33 degrees, then placed in a saucer upon the eataljles, 

 and afterwards set fire to by means of a match. A considerable 

 dilatation immediately takes place,\vhich expels the atmospheric 

 air ; and in order to prevent its return into the apparatus, the 

 hole in the top of the bell is quicklv stopped with common wax. 

 A small (piantity of atmospheric air may perhaps get again into 

 the bell ; but not more, it is probable, than the combustion of 

 the spirit of wine, not yet finished, will sulfice to decompose, and 

 convert into carbonic acid gas, the prebcrvative property of which 

 is well known. — Paris Journal. 



ARTrFiriAL CONGlCr.ATION. 



The interesting experiment, l)y Professor Leslie, which we 

 announced in our last number, has been successfully repeated 

 by Mr. Slodart. The stone from which he made his al)sorbent 

 powder was taken from Salisbury Craigs, near Edinburgh : this 

 was pounded and dried; and with it, under an exhausted receiver, 

 n small bofly of water was soon frozen. On procuring a very low 

 receiver, and preparing a larger surface of earth, the process was 

 accelerated, a larger body of water being soon converted into a 

 Vakc of ice. Ex])criments were made with various other absorb- 

 13 b 3 ents, 



