300 Wisconsin Academy of Sciences, Arts, and Letters. 
liberated from a magnesium! chloride solution when the powder 
was present in excess, the action being finally checked by the 
accumulation of the precipitate formed; but up to the maxi¬ 
mum, the quantity of hydrogen disengaged was nearly propor¬ 
tional to the amount of magnesium added. After magnesium 
had acted upon the solutions'of the chloride and acetate, these 
latter were found to contain but a relatively slight excess of 
base. The analytical data, show that the precipitates formed 
were very basic chloride and acetate of magnesium respect¬ 
ively. In the case of the sulphate of mjagnesium the solution 
was much weaker after the magnesium had acted upon it, a 
very considerable portion of the salt having been, thrown down 
in combination with the hydroxide of magnesium in form of 
a basis sulphate of magnesium. Lemjoine’s explanation of the 
action of magnesium on solutions of magnesium salts is that in 
these solutions the salts are slightly decomposed into hydroxide 
of magnesium and free acid. This acid acts on the metal form¬ 
ing hydrogen and a basic salt which breaks up into the nor¬ 
mal salt and hydroxide of magnesium; the latter finally drops 
out of solution and the reaction begins anew. In advancing 
this explanation it would certainly seem that Lemjoine did not 
give due weight to the fact that the reaction of the solutions 
of the magnesium salts toward indicators is perfectly neutral 
at the outset, and that soon after introducing the magnesium 
it becomes alkaline and remains so while the liberation of hy¬ 
drogen continues unabated. There are thus no facts upon 
which to base the assumption that the salts he used are even 
slightly decomposed by water into free acid and magnesium hy¬ 
droxide. 
H. Mouraour 1 again directed attention to the fact that mjag¬ 
nesium liberates hydrogen readily not only from solutions of 
its own Salts, but from solutions of other salts as well. He 
found solutions of the carbonate 1 , chloride 1 , oxalate and sulphide 
of ammonia strongly acted upon; but no action was observed 
in the case of solution of fluoride of ammonium. Sodium car¬ 
bonate, acetate and tetraborate solutions were strongly acted 
iComptes rend. 130, 140, 1900. 
