of the 1th of January, 1831. 265 



I regret much that I had not a magnetic needle so adjusted, 

 that I might have observed whether the aurora had any mag- 

 netic influence. As it is not improbable that we may have a re- 

 petition of the phenomenon, I shall take care to be prepared in 

 this way. I am not aware that, before this, any luminous 

 arch has been observed towards the south, in this part of the 

 globe, and I am very anxious to hear what observations have 

 been made on this arch farther to the south. Dr. Gregory is 

 at present at Hastings, and I intend inquiring of him, whether 

 an arch was observed to the south of that place ; if so, at what 

 elevation at 5h. 30m. ; and if not, whether the arch appeared 

 to the north at that time : its elevation at these two places 

 would pretty nearly determine its absolute height above the 

 earth's surface. As I saw them, the phenomena between five 

 and six o'clock, and between ten and eleven, were repeated 

 nearly in the same order: the strongest red light appearing 

 first in the N.E., and the coruscations succeeding the dis- 

 appearance of the luminous arch in both cases. The tem- 

 perature was rather low, but steady, about 24 F. during the 

 whole time ; the barometer high and steady (last night at 

 12h. 45m. 30-64 ; now 2h. P.M. 30-59). 



ON THE MECHANISM OF THE ACT OF VOMITING. 

 BY MARSHALL HALL, M.D., F.R.S.E., &c. &c. 



T WAS greatly interested by the following extract from the 

 valuable Report of cases in the Meath Hospital, just pub- 

 lished by Drs. Graves and Stokes, in the fifth volume of the 

 * Dublin Hospital Reports and Communications.' 



* A man about forty years of age died of tubercular phthisis. 



* The oesophagus, after passing through the usual opening 

 in the diaphragm, was found to re-enter the thorax by another 

 very large opening in the tendinous portion towards the left 

 side. The stomach occupied the inferior portion of the left 

 thoracic cavity, its cardiac and pyloric extremities both lying 

 in the opening. 



' The man vomited frequently while under observation in 

 the hospital, Now, as the stomach was placed entirely out of 



