ISO Scientific Intelligence. 



ducts in a given time, and the third the time required for the conduction 

 of equal quantities of electricity. 



Muriatic acid, 



Acetic acid. 



Nitric acid. 



Ammonia, 



Solution of muriate of ammonia. 



Sulphuric acid, 



Solution of potash 



Solution of common salt. 



Solution of acetate of lead. 



Distilled water, 1.000 1.000 1,000 



II. NATURAL HISTORY. 



MINERALOGY. 



12. Notice of the produce of the Tin Mines of Cornwall and' Devon.'-' 



Cornwall. Devon. 



1822, 3127 tons. 10 tons of tin. 



1823, 4010 21 



1824, 4770 49 



1825, 4100 70 



1826, 4320 86 



13. Of the Cornish Copper Mines.'-~ 



Average pro- 

 Tons of ore. duce of metal. Sold for 

 12 Months to 30th June 1823, 97.470 8| per cent. L.618,933 

 Do. 1824, J 02.200 7| 603,878 

 Do. 1825, 110.000 7| 743,253 

 Do. 1826, 118.768 7| 799,790 

 Do. 1827, 128.459 7| 755,358 



14. Of the qtuLntity of Metallic Copper, the produce of the mines in Great 

 Britain and Ireland. — 



Year to 30th June 1823. 1824. 1825. 1826. 1827. 



9715 9836 10350 11069 12381 



From the Trans. Cornwall Geological Society, vol. iii. 



