Page [299]

ACTION OF METALLIC MAGNESIUM UPON AQUEOUS
                       SOLUTIONS.
                  ]BY LOUIS RAHLENBERG.
  It has long been known that metallic magnesium acts ex-
tremely slowly upon distilled water, and that it practically does
not act at all upon solutions of the caustic alkalies. In 1899
TobmmasiI made qualitative investigations of the action of
magnesium on aqueous solutions of the following salts: KCl,
NH4C1, CaChl, iMgCI.2, NaCl, LiC1, BaCh2, SrCl2, CuCl2,
CdCJ2, PbCl2, EigC12, FeCel, CrC13, PtGl4, AuC3, CUSO4,
ZnSio4, P:eSO4, MnS014. He found that from   solutions of
NaCl, KCl, and LiCl magnesium liberates hydrogen more rap-
idly than from, pure water, magnesium hydroxide being formed.
Solutions of the chlorides of barium, strontium and calcium
were acted upon but feebly by magnesium, but ampmonium chlo-
ride solution was attacke dat a lively rate. From -solutions, of
the salts of the heavy metals mentioned above, hydrogen was
liberated by magnesium, the chloride or sulphate of that metal
being formed, and a basic salt or hydroxide of the heavy metal,
or the latter in the metallic state, being precipitated. No theo-
retical explanations were attempted. In the same year G. Le,
moine2 called particular attention to the action of magnesium
upon aqueous solutions of magnesium salts. He used solutions
of the nitrate, ehloride, sulphate and acetate of magnesium,
but worked especially with the last three salts. From aqueous
solutions of these salts magnesium liberates hydrogen rapidly
and continuously. Using magnesium in form of powder, he
found that about 0.4 the calculated amount of hydrogen was
'Bull. Soc. Chim. (3) 21, 885-887, 1899.
2Comaptes rend. 29, 291, 1899.
L..
I ---        - W-..    --   -     -1 - F ,- ,        .- , 11I