356 Electro-Magyieiic and Magneto- Electric Formula. 



when the acid is suffered to fly off. Nothing remains but the 

 brown lac-stained Hquid. 



Liquid carbonic acid did not appear to act on any of the metals 

 or oxides, but the experiments on this point demand a further 

 examination. Its inaction is probably owing to the want of the 

 force of ' presence/ or of ' disposing affinity.' 



When the liquid has been frozen in a tube of glass, the tube 

 may be melted off by the blow pipe, and hermetically sealed. 

 Such a tube will always retain the liquid, or gas, the former, if 

 in suflicient quantity, at all temperatures, if not, the latter alone 

 will be found in it at high temperatures. I have one such tube, 

 which begins to show moisture at 56°, and exhibits a constantly 

 elongated cylinder of liquid, as the coldness is increased. At 32° 

 the cylinder is about half an inch in length. 



Carbonic acid mechanically powerful as it is, is not applicable, 

 perhaps, either to locomotion or projection ; but though the rea- 

 sons for this are most of them obvious, the Franklin Institute has 

 appointed a committee to investigate and report on the subject, 

 that the exact truth may be known, and the waste of time and 

 talent likely otherwise to be experienced, be saved to the country. 



Art. XYII. — On a general Electro-Magnetic and Magneto- 

 Electric Formula. 



Extracted from the Journal of Chemistry, by Erdmann and Schvveigger Seidel, and 

 forwarded for insertion in this Journal. 



Mr. Schweigger repeated on the 26th of July, 1834, before 

 the Society of Physiciens of Halle, several of the experiments 

 which he had already performed in his public lectures in the 

 University. He demonstrated by those experiments that a mag- 

 net turning around its axis, produces a greater accumulation of 

 electricity than a couple of small disks of zinc and copper, of 

 about the size of a half crown, (or half dollar,) and are wetted 

 in a solution of muriate of soda. For whilst the current of this 

 hydro-electric combination produced a constant deviation of the 

 needle of 30° to 40°, they observed in turning the magnet, in- 

 stantaneous deviations of 160° to 170°, and the magnet being con- 

 tinually turned, the needle finally stopped between 60° and 70°. 



