142 
“ On the action of Water and dilute Saline solutions upon 
Lead ” Part iii. By M. M. Pattison Muie, F.KS.E., 
Assistant Lecturer on Chemistry, the Owens College. 
1. In the second part of these researches (Proc. Manch. Lit. 
and Phil. Soc., xvi. 1) I shewed that there is generally an 
increase in the solvent action of water and dilute saline 
solutions upon lead when the experiments are carried out 
in beakers covered with porous paper ; also that exposure 
of large surfaces of liquid to the surrounding atmosphere 
generally tends to increase solvent action. Further my 
experiments led me to conclude that the solvent action 
tends to attain a maximum when the volume of liquid is 
large in proportion to the surface of lead exposed. I also 
concluded that under favourable conditions the quantity of 
lead dissolved increases in an increasing ratio with the time 
during which the action is allowed to proceed. (Compare 
Par. G). Finally, I expressed my belief that the purity of the 
lead upon which the various liquids are allowed to act, very 
materially conditions the solvent action of those liquids. 
In the present communication I propose to bring forward 
further experimental evidence as regards some of these 
points, and also to touch upon certain circumstances condi- 
tioniug the solvent action of dilute saline solutions upon 
lead which have not as yet been studied. 
2. And the first point which demands attention is one 
which I merely mentioned in my second paper, viz.. Does the 
relation between surface of lead exposed and total quantity 
of liquid influence the solvent action ? In the following 
experiments the surface of lead exposed was maintained 
constant, the strength of the saline solution was also un- 
changed, but the total quantity of liquid was increased. 
Otherwise the experiments were carried out under exactly 
similar conditions. 
