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The Chemistry of the Future. 
297 
de Boisbaudran succeeded in purifying the body which he 
had obtained, and in accurately determining its properties 
and reactions, the more closely did it approximate to M. 
Mendeleeff’s “ eka aluminium.” It must be distinctly un- 
derstood that the prediction had not been couched in loose 
generalities like the prophecies of the late Francis Moore, 
Physician. In 1869 M. Mendeleeff wrote as follows : — “ Its 
atomic weight will be El = 68; its oxide, E 1 2 0 3 ; its salts 
will present the formula E 1 X 3 . Thus its (only ?) chloride 
will be E 1 CL, yielding on analysis 39 per cent of metal and 
61 of chlorine, and will he more volatile than ZnCl 2 . Its 
sulphide, E 1 2 S 3 , or oxysulphide, E 1 2 (S, 0 ) 3 , will be preci- 
pitable by sulphuretted hydrogen and insoluble in ammonium 
sulphide. 
“ The metal will be easily obtained by reduction ; its 
specific gravity will be 5*9, consequently its atomic volume 
will be 11*5 ; it will be almost fixed and fusible at a low 
temperature. It will not become oxidised in contaCt with 
the atmosphere, and at a red-heat it will decompose water. 
The pure metal melted will be slowly attacked by the acids 
and alkalies. The oxide, E 1 2 0 3 , will have the specific gra- 
vity 5*5, or thereabouts ; it should be soluble in strong acids, 
form an amorphous hydrate insoluble in water, but soluble 
in acids and alkalies. The oxide will form neutral and 
basic salts, El 2 (OH,X) 6 , but not acid salts; its alum, 
E 1 K(S 0 4 ) 2 I 2 H 2 0 , will be more soluble than the correspond- 
ing salt of aluminium and less crystallisable. The basic 
properties of E 1 2 0 3 being more decided than those of A 1 2 0 3 , 
and less than those of ZnO, it will be precipitable by car- 
bonate of baryta. The volatility, as well as the other 
properties of the saline compounds of El, being the mean 
between those of aluminium and those of indium, it is pro- 
bable that the metal will be discovered by means of speCtrum 
analysis, as was the case with indium and thallium.” 
This very definite account may be read in “ Liebig’s An- 
nalen ” (Supplement-Band viii., p. 133, 1871), and it has 
indeed been most strikingly confirmed by the properties of 
the metal as observed by M. Lecoq de Boisbaudran. We 
must particularly bear in mind that this accord between 
prediction and observation is evidently becoming more com- 
plete as the new metal is obtained in larger quantities and 
in a state more closely approximating on purity. The cele- 
brated French chemist, indeed, remarks — “ Supposing the 
forecasts of M. Mendeleeff verified altogether, I should have 
been led to seek for gallium in the precipitates formed by 
ammonia, and not, as I have done, in the ammoniacal 
VOL. vii. (n.s.) x 
