On the Oxidation of Metals, particularly of Lead. 365 

 exhibited a greenish colour, gas being given out from both 

 wires, which also were turned black. 



These two experiments led me strongly to conceive that 

 an alkali must have been formed during the operations, see- 

 ing that alkalis produce precisely the same effects : to prove 

 this, I restored the blue colour of the litmus by a few drops 

 of dilute sulphuric acid, thinking that the acid would com- 

 bine with the alkali formed ; which was the case : it was 

 again submitted to galvanic action, which effected a change 

 of the blue colour, and the production of a green as before. 



Taking a fresh quantity recently made, I changed its co- 

 lour to red with the above acid, and, on galvanizing it in the 

 same manner, had the pleasing satisfaction to find that the 

 red became very soon blue in consequence of a production of 

 alkali which must have saturated the acid. 



Having repeated these experiments several times with the 

 same results, I was fully satisfied as to the formation of an 

 alkali ; but wanting more proof, to a portion of the infusion 

 of litmus, Which had been turned green, I added a few drops 

 of the sulpruUe of iron, a slight precipitation of which in the 

 state of a red oxide took place : this is ahvavs the case when 

 an uncombined alkali is present. Syrup of violets diluted 

 with an equal quantity of distilled water, and galvanized 

 with silver or iron wires, turned as perfectly green as it 

 could have done on the addition of pure ammonia, potash, 

 or soda. If these facts are in the least new or interesting, 

 by their insertion in your valuable magazine you Will much 

 obliee, Yours respectfully, 



CSty Dfapttfal* Di GJM&twi 



Orocer's-Hall Court, Poultry, 

 '20t\\ Sept. i 



LX. Letter from Dr. Dela villi: to M. Vauquelin, 



upon the Oxidation of Metals, and particularly of 

 Lead*. 



1 HAVE beetl sonic time in the habit of pursuing, :h often 



as my other occupations would permit, some experiments 



• From 



upon 



