OXIDATION OP LEAD. 



a disk would oppose to its separation ; we may be certain," 

 that e is less than e\ if the resistance opposed by a disk 

 be less than the resistance thus calculated. 



XIV. 



Letter from Mr. Delaville, M. D. of Cherbourg, to Mr. 

 Fauquelin, Member of the Institute, on the Oxidation 

 of Metals, and particularly on that of Lead*. 



SIR, 



I m 



AVE undertaken, and pursued as far as my occupa- Experiments on 

 pations would allow me, some experiments on the oxida- oxl ^" tlon of 

 tion of metals, particularly on that of lead; and thovgh the 

 results I have obtained are such as to inspire me with a wish 

 to push my inquiry still farther, as the publication of these 

 results, which I conceive to be not yet known, at least to 

 many, may throw some light on the theory of oxidation in 

 general, and contribute to render more economical the oxi- 

 dation of lead in particular, as well as the preparation of 

 some salts, that have this metal for their base, I shall do 

 myself the honour of sending you a short account of these 

 results, and of the means I adopted to obtain them. If 

 like me you think them new, at least in some respects, I 

 beg you would give them that sort of publicity, that may 

 appear to you most suitable. 



It is known, that, in cleaning bottles, when a small shot oxided in 

 quantity of shot is shaken in water, the friction in a short washing bottles, 

 time separates particles of lead, which, being suspended in 

 the water, render it turbid, and give it a slate gray colour. 

 If the agitation be carried farther, the particles suspended 

 in the water become of a lighter gray ; and by continuing 

 it they grow whitish, and at length of a pretty fine 

 white. 



This oxide of lead has such a tendency to unite with The oxide pow- 

 carbonic acid, that on being exposed to the air, when erfully attracts 

 taken out of the air, it is covered almost immediately with cai 



* Annales de Chimie, Vol. LXVI1L p. 92. 

 Vol. XVIL August, 1807. X a pellicle 



