Miscellanies. 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 to me 

 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 j 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 I 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. 



