Dubois.] 458 [December. 



Mr. Dubois placed before the Society, specimens of Mag- 

 nesium, lately procured from London for the Cabinet of the 

 Mint, and for experiment. 



Magnesium wire is not an entirely new article in this country ; 

 but perhaps the ingot is so, and is especially curious. Of all the 

 metals which remain fixed in open air, this is the lightest ; the 

 sp. gr. being 1.70, or less than one-twelfth that of platinum, which 

 stands at the other extreme of the scale (and of which a specimen 

 weighing one-third more than the magnesium, is shown for comparison). 



This metal is now readily manufactured in England, by a process 

 patented in 1863, and is sold in London at a price equal to 85.25 

 in gold, per ounce, av'd. Its physical properties are such as to give 

 little promise of utility, except for the purpose of illumination. A 

 wire of this metal, held in an ordinary flame, ignites and burns with 

 a dazzling brilliancy, giving out a white light. On this account it is 

 used in photography, to take pictures at night, or in places where 

 the sun cannot penetrate. The wire appears ductile and pliable, but 

 has really not much tenacity, and snaps off when bent around to the 

 horseshoe shape. It is, in fact, not formed by rolling and drawing, 

 but by the hydrostatic press, from the solid cake ; somewhat as lead 

 pipe is made. This specimen has a diameter of one-sixtieth of an 

 inch. One hundred inches of such wire will weigh about fifteen 

 grains, and would cost eighteen cents (gold) in London, at the rate 

 above stated. 



The metal being too brittle to be cut with a chisel, this piece of 

 ingot, as will be seen, has been detached by sawing. 



Mr. Eckfeldt has made a pretty full examination of its chemical 

 properties, which will here be briefly summed up. 



It is slightly soluble in sulphuric acid of commercial strength ; the 

 action is violent when the acid is diluted. 



The solution is active and complete in nitric and muriatic acids 

 of ordinary strength. 



It is also dissolved by the vegetable acids, such as the acetic and 

 tartaric, but slowly by the oxalic. In a solution of carbonate of soda 

 it dissolves very slowly, but more actively with heat, when it is con- 

 verted into a carbonate. In caustic potassa there is no action. 



It is not afl"ected by water, either at 60° F. or at the boiling-point, 

 except to produce a slight tarnish. The water, however, is decom- 

 posed by it. Moist air makes a slight oxidation. These specimens 

 came across the ocean, however, in a paper box, without losing the 

 metallic lustre. 



