Intelligence ■and Miscellaneous Articles. 71 



which sometimes contain a considerable proportion of silica. Having 

 ascertained the composition of the two layers which form the scales, 

 M. Mosander examined whether they were similar throughout : he 

 found the outer part of the external layer contained more peroxide 

 than the entire scale, viz. 52-77 instead of 34-65, but the second 

 layer, in contact with the iron, was found to be homogeneous 

 throughout. It results from these experiments that these scales 

 are not homogeneous; that the first layer contains more peroxide 

 in proportion to its nearness to the exterior surface ; but the second 

 layer is homogeneous, and maybe considered as formed of 3 atoms 

 of protoxide with 1 atom of peroxide. — Ann. de Chim. et de Phys, 

 Feb. 1827. 



gUANTITV OF SILVER AND GOLD RAISED IN GUANAXUATO. 



The following statement, drawn from the registers at the Assay 

 Office, show a considerable decrease in the amount of silver and 

 gold raised in Guanaxuato, before and after the year 1810; the 

 produce of silver being reduced to a fourth, and that of gold to 

 a fifth of what it had been in the year 1809. 



Before the year 1810. After the year 1810. 



Years. Silver Marks. Gold Marks. 



1801 .. 342,608 1,457 



1802 .. 502,497 1,676 



1803 .. 750,887 1,538 



1804 .. 755,861 2,228 



1805 .. 723,789 2,495 



1806 .. 618,417 2,188 



1807 .. 578,735 2,396 



1808 .. 617,474 1,842 



1809 .. 620,012 2,189 



Years. Silver Marks, Gold Marks. 



1810 .. 511,445 1,412 



1811 .. 270,206 550 



1812 .. 357,930 907 



1813 .. 292,211 462 



1814 .. 337,795 708 



1815 .. 275,905 841 



1816 .. 269,711 694 



1817 .. 199,706 S23 



1818 .. 155,112 401 

 Report of the United Mexican Mining Association, March 1827. 



NATIVE IRON FOUND IN CANAAN. (cONN. U. S.) 

 The following notice is from Silliman's JowrMa/, March 1827. — 

 " We are informed by Mr. W. Barrall, in a letter dated August 16, 

 1826, that his father was surveying a piece of land on the mountain, 

 about three years since, and by accident noticed a black vein in a 

 quartz rock ; he pounded upon it sometime with a stone, and with 

 considerable difficulty got out two small pieces, the largest of which 

 is in our possession. — He has never been at the place since ; and 

 probably no other person has discovered it or knows where it is. 

 It is surrounded by woods one or two miles on every side, and it is 

 on the top of a mountain 700 or 800 feet above the common average 

 of the land in the town. Mr. Barrall says there is evidence in that 

 quarter of masses of iron or its ores, of considerable extent, as his 

 compass was materially affiicted ; but the particular vein from which 

 he obtained the pieces appeared to be of no great extent ; and the 

 width is the same as that of the piece in our possession, which 

 measures two inches wide and two thick. — It weighs eight ounces. 

 The following notice of the same facts has been received from 

 Mr. C. A. Lee. 



Native 



