226 An Account of the Pftroht/m IVelh 



mained as iifual ; but, when lie expofcd it to galvauifm, the 

 wire a began to be oxydated, while the wire at b preeipitntcd 

 the copper from its folution. The wires a and h being of 

 filver, and the tube filled with a folution of filver in nitrous 

 acid, the efieol was the fame. The fame thing took place in 

 a folution of zinc in the nuiriatic acid when the wires a 

 aud b were of zinc. 



Exp. XVI, The fame eRcct is produced if the aflinity of 

 the bodies diflTolved is greater for the acid than that of the 

 wire immerfed in it. 



The wires a and h were of copper, and the tube contained 

 a folution of zinc; a and h were of lilver, put into a folution ot 

 copper or zinc ; a and h were of gold, put into a folution of zinc. 



In all thefe cafes there was a precipitation at />, and an ox- 

 ydation at a. It was not neceffary that the wires fliould be. 

 of different metals- The law was always confiant. 



Such is the feries of pha^nomcna obferved by M. Richter. 

 The celebrity he has fo jufllv acquired gives reafon to think 

 that thefe experiments have been made with exaftnefs. If 

 the commiflion appointed by the Inftitute to purfue this 

 labour examines and confirms them, it is to be expelled that 

 they will produce changes in the laws of affinity. 



XXVIil. An ylc count of the Petroleum ] Veils in the Bunnha 

 Doininiom : extracted from the Journal of a Voyage from 

 Uanghong up the River Erai-lVuddej to Amarapoorahy 

 the prefent Capital of the Burmha Empire. Bj Captai/i 

 ll I R A M Cox, Befident at Banghong * . 

 Saturdaj^ Jan. 7, ^791' 



VV IND eaflerly, (liarp and cold, thick fog on the river 



until after fun-rife, when it evaporated as ufual, but foon 



after collected again, and dfcntinued fo dcirfe till -half paft 



eight A. M. that we could barely fee the length of the boat. 



Thermometer at fun-rife 52'', at noon 74% in the evening 



69"; general courfe of the river north 20'^ well, main breadth 



from one mile to a mile and a half, current about two miles 



and 4 half per hour. 



■•' From the Afiatlc Rfcurcbe^f Vul. VI. 



Kafl 



