366 On the Oxidation of Metals, particularly of Lead. 



upon the oxidation of metals, and particularly that of lead ; 

 and as the results I obtained were of a nature sufficiently en- 

 couraging to induce me to proceed in my researches, I re- 

 quest that, if you are of the same opinion, you will give that 

 decree of publicity to them you may think proper. 



We know that upon rinsing a glass bottle with a little 

 water and lead (small shot), the friction soon detaches small 

 portions of the lead, which, being suspended in the water, 

 give it at first a slate colour ; if the agitation is a little longer 

 continued, the water becomes grayish, and a little longer still, 

 it becomes whitish, until at last it is of a very fine white. 



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

 bonic acid, that when exposed to the open air, upon being 

 taken out of the water, it becomes almost immediately co- 

 vered with a pellicle of a brilliant whiteness, which seems to 

 be nothing else than carbonate of lead. 



This oxide of lead remains always under water without 

 experiencing any sensible alteration, either in the shade or 

 in the light ; but if, when it is inclosed in a crystal bottle 

 full of atmospheric air, and containing a small quantity of 

 water, there is any of it sticking to the inside of the bottle 

 above the level of the water, and if the bottle is exposed to 

 the rays of the sun, in this case the portion of oxide exposed 

 to the light will be seen to pass successively to the yellow, 

 and from the vellow to the red, and thus furnish masticot 

 and minium. 



This white oxide exposed in a glass capsule to the heat of 

 a fire, soon passes from the white to the yellow, and from the 

 yellow to the red, in the same manner as that which was ex- 

 posed to the light. 



This oxide may be made in great quantity, and at a small 

 expense, and on this account render some preparations less 

 costly in which it may be employed j it may be also made 

 use of in painting. 



The following is the method I had recourse to in order to 

 obtain this oxide : I inclosed a quantity of lead (small shot) 

 in a leaden barrel, into which I poured about one fifth of 

 water ; I allowed the rest of the capacity of the barrel to be 

 filled with atmospheric air, and I turned the barrel round by 



means 

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