g© G alv an tftn.— ^Natural H'yhry. — Comets. 



Mr. Cruickflrank gives the following as an entertaining 

 experiment: — Fill a velfel, of about the capacity of three 

 pints, with oxymuriatic gas; fee that it is drained from the 

 water in it ; then throw into it about a dram of good ether, 

 and cover the velfel with a piece of paper. In a few feconds 

 a while vapour will be obfervcd moving circularly : this will 

 be followed by an explofion and flame, and a large quantity 

 of carbon will be depofitcd. 



GALVANISM. 



Mercier has quoted a work, publifhed 27, years ago, which 

 contains the principle of galvanifm. Twelve years before, 

 the celebrated Sulzer difcovered this principle, and obtained 

 the fame refult. '•' If you join," fays he, " two pieces of 

 metal, one of lead and the other of filver, in fuch a manner 

 that their edges form one plane, and if they be placed upon 

 the tongue, a tafte of the vitriol of iron will be felt, while 

 each piece feparately leaves no trace of tafte." — Smith's Pojl- 

 bumous /f'orhf part ii. p. 308. 



NATURAL HISTORY. 



A very ftrong leaden pipe, which conveyed water into a 

 bafon in the garden of the palace of the Confervative Senate, 

 the ci-dcvant Luxembourg, and which has wol been in ex- 

 iflence for 30 or 40 years paft, has lately been difcovered. 

 This pipe contained a fediment depofited by the water, 

 vv hich, hardened by time, had become ftone, or rather free- 

 flone, fufficiently clofe to ftrike fire with fteel without the 

 lead which contained it being in any manner altered. Had 

 the workmen taken the precaution to remove the lead with- 

 out touching the matter, they would have preferved a curiofity 

 unique in its kind ; a natural pipe from 3500 to 3000 feet 

 long, of the mod compacft freeftone, and an inch and a half 

 in thicknefs. In its whole diameter there were counted about 

 fifty concentric ftrata or coats. 



COMETS. 



*' In the Journal de Paris of May 28, Caigne the notary 

 announced, that he would give 600 francs to the perfon who 

 fhould difcover a comet. On the morning of July ] 3, C. Pons, 

 keeper of the obfervatory of Marfeilles, difcovered one, and 

 in the evening it was obferved alfo by three able aftronomers' 

 at Paris. The Board of Longitude being requefted to adjudge, 

 the prize, thought that C. Pons had a kuid of priority, though 

 he did not make his obfervations known till the evening : be- 

 fides. the three aftronomers of Paris coufented, and C. Pon* 



had 



