JViscellanies. 401 
nant for a time, and the beer in a sour state. The substitution of 
block-tin would remove the apprehension of danger, but its greater 
price offers a strong temptation to the use of lead. It appears tome 
that the lead tube lined with tin, will answer the ends of cheapness, 
safety and durability. I would therefore, invite your attention to the 
following experiments, which if you think them of any importance to 
the public, you may insert in your Journal. 
Experiments.—Various portions of lead tube coated some witn 
pure tin, and others with different alloys of tin, and lead were bent 
into the form of a semi-circle, and filled with vinegar of different de- 
gree of strength.’ After standing, some a month, and others six 
weeks, with occasional disturbance, the clear solutions were tested, 
first with sulphate of soda and afterwards with bi-hydro-sulphuret of 
ammonia. ‘The application of the first of these tests, viz. sal. soda 
produced no alteration in any of the solutions; from which it must 
be inferred that they contained no lead. 
The application of the second test produced, as was anticipated, a 
brown precipitate of sulphuret of tin. In the same manner, two fresh 
pieces of tube were filled with a strong solution of common salt, 
which remained in contact for some time. The solutions, when as- 
sayed with the same tests, shewed that nothing but a little tin was dis- 
solved. 
It appears that in all these cases, which J regard as galvanic effects, 
the tin was the most oxidable metal, although, when not under the 
influence of polar arrangement and in the open air, lead appears to 
oxidate sooner than tin. It is scarcely necessary to remind you, that 
results similar to these were obtained thirty years ago by the celebra- 
ted professor Proust at Madrid, who undertook, for the Spanish 
government, an extensive series of experiments on the different al- 
loys of lead and and tin, with the express view of determining wheth- 
er the popular prejudice against the coating of copper vessels with an 
alloy of tin and lead, which is the common practice, was ill, or well 
founded. Nothing can be more satisfactory than the conclusions he 
drew from his labors, viz. that as in all his numerous experiments nei- 
ther lead nor copper were dissolved, there is little reason to fear the 
solution of lead from the tinning of our kitchen utensils. I may just 
mention here, that I am in the habit of cleaning out my soda fountain 
every spring, with dilute muriatic acid, which uniformly dissolves the 
oxide of tin without touching the copper, which I am persuaded will 
remain as securely, as the sheathing copper in Sir Humphry Davy’s 
great experiment and for the same reason. 
