147 
sample, No. 1, contained small quantities of Antimony and 
Tin, very little Iron, no Manganese, Copper, or Bismuth, but 
traces of Aluminium : the impurities in No. 2 sample were 
the same as in No. 1, small quantities of copper being also 
present. The results are very startling. With No. 1 sample 
of commercial lead, less lead was dissolved in almost every 
case than with “pure” lead; with No. 2 sample, whose 
chemical composition appears almost the same as that of 
No. 1, very much larger quantities were dissolved. I at 
once supposed 'that the fact noticed by some previous ex- 
perimenters, viz., that mechanical treatment of lead alters 
its power of withstanding the action of solvents, must have 
materially influenced the results. That mechanical treat- 
ment does alter lead to an astonishing degree, so far as the 
action upon it of saline solution is concerned, will be made 
apparent from the experiments detailed in par. 12. 
Table VI. 
Experiments in Cork Flasks, nearly filled with liquid (SOOcb.c.) 
Salt. Grams ' 
Surface 
“Pure” Lead. 
Total Lead, 
in Mgms., 
dissolved 
Commercial 
Lead No. 1. 
Total Lead, 
in Mgms., 
dissolved 
Commercial 
Lead No. 2. 
Total Lead, 
in Mgms., 
dissolved 
per litre. 
of Lead. 
after 
after 
after 
sq. cm. 
6 days. 
14 days. 
6 days. 
14 days. 
6 days. 
Distilled Water ... — . 
.. 25 .. 
. — 
.. 1-2 . 
..trace 
..trace. 
.. 12-0 
Potassium Nitrate. 0 20 . 
.. 25 .. 
. 09 
.. 1-2 . 
.. 0-3 
.. 0-4 . 
5-0 
Ammonium „ O' 20 . 
.. 25 .. 
1-3 
.= 1-8 . 
.. T5 
.. 1-0 . 
.. 120 
Distilled Water ... — . 
.. 50 .. 
. 0-7 
.. 0-9 . 
.. 0-5 
.. 0*5 . 
.. 16-0 
Potassium Nitrate. 0'20 . 
.. 50 .. 
11 . 
.. 1-2 . 
.. 1-7 
.. 0-5 . 
.. 12-0 
Ammonium „ 0‘20 . 
. 50 .. 
1-4 . 
.. 1-5 . 
.. 7-0 
.. 7-0 
.. 7-0 
Experiments in 
Beakers, 500cb.c. liquid 
IN EACH, 
Distilled Water ... — 
.. 25 .. 
. 0-4 
.. 0-5 
.. 0.3 
.. 0-3 
.. 0* 5 
Potassium Nitrate. 0*20 
.. 25 .. 
. 0-4 
.. 0-4 
.. 0*3 
... 0*3 
. . trace 
Ammonium „ 0‘20 
.. 25 .. 
. 1*2 
.. 2-0 . 
.. 1-0 
... 1*0 
. . trace 
Distilled Water ... — 
.. 50 .. 
. 0-7 
... 1-2 
.. 0-3 
... 0-3 
. . trace 
Potassium Nitrate. 0 20 
.. 50 .. 
. 1*4 
... 2-2 
.. 0*3 
... 04 
. . trace 
Ammonium „ 0‘20 
.. 50 .. 
. 2-3 
... 3-5 
.. 0-3 
... 0-5 
. . trace 
10. These experiments appear to show that it is not so 
much the chemical purity of the lead, as the mechanical 
