The Georgia Bauxite Deposits. — JVatsoii. 37 
percentages of ALO3 and IrLO in the best grade of the Georgia 
bauxite certainly correspond to the formula AloO:;.3H.O, the 
trihydrate. In a majority of analyses a variable percentage of 
soluble AI0O3. in ioo°C. of 50°B. sulphuric acid is found, which 
ranges from a fraction of i per cent, in the purest ore, to 40 
and 45 per cent, in the associated bauxitic clays, which are 
shown to grade into each other. The insoluble AUO. is prob- 
ably present in the form of the hydrous aluminum silicate, clay, 
admixed possibly as Phillips suggests with a lower hydrate of 
alumina. The Georgia bauxites, therefore, in their purest 
form, consist in most cases of a mixture whose base or essen- 
tial part is the trihydrate of alumina. All gradations in which 
the soluble alumina ranges from about 60 per cent, to several 
per cent., or pure trihydrate of ALO.,, to bauxitic clay, corre- 
sponding to the hydrous aluminum silicate, are known. 
As remarked by Liebreich, chemical analyses of the mineral 
from different localities show differences in chemical composi- 
tion. Thus we have analyses which correspond to the three 
hydrates mono- di- and tri- of AUO^j.wdiich strikingly illustrates 
the variable character of the so-called mineral bauxite. 
So far as the writer can gather from the various accounts 
and descriptions in which analyses of bauxites from the ])rin- 
cipal localities, both foreign and American are given, much 
depends upon the origin, as to the chemical composition of the 
mineral. AUOy forms, however, in all cases, the basis ; and it 
ranges from 55 to 85 per cent, according to locality, with cor- 
responding variable proportions of water of chemical combin- 
ation, ranging accordingly from 15 to 34 per cent. Thus, de- 
posits of the mineral are known which correspond on analyses 
with the three hydrates of ALO:,. 
While the so-called mineral bauxite corresponds in chemical 
composition, according to locality, to the three natural hydrates 
of alumina, as a rule, no resemblance in physical ])roperties 
known at present is shown to the minerals diaspore (monohy- 
drate) and gibbsite (trihydrate). 
Since this correspondence therefore in chemical composition 
to the three hydrates does exist, the question i§ naturally sug- 
gested, whether the mono- and tri- hydrates known as the min- 
erals diaspore and gibbsite, do not really occur with 
physical properties dift'erent from those usually record- 
