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705 Jayne Street. 


Xo apology is necessary in presenting a work on 
aluminium in English. In 1858 Tissier Bros, pub- 
lished in France a small book on the subject. H. 
St. Claire Deville, the originator of the aluminium 
industry, published a treatise, also in French, in 
1859. Deville's book is still the standard on the 
subject. Until December, 1885, we have an inter- 
mission, and then a work by Dr. Mierzinski, 
forming one of Hartleben's Chemisch-Techuische 


Bibliothek, which is a fair presentation of the 
industry up to about 1883, this being a German 
contribution. Probably because the English- 
speaking people have taken comparatively little 
hand in this subject we find no systematic trea- 
tise on aluminium in our language. The present 
work aims to present the subject in its entirety to 
the English reader. 

Tissier, Deville, Mierzinski, and the German, 
French, and English scientific periodicals have 


been freely consulted and extracted from, full 
credit being given in each case to the author or 
journal. As this art has of late advanced so 
rapidly it has been a special aim to give every- 
thing that has been printed up to the time of pub- 

The different parts of the work are arranged in 
what seemed their logical order, corresponding 
closely to that followed by Deville. The Appendix 
contains an account of laboratory experiments, etc., 
several of which, it is trusted, may be of value. 

In conclusion, the author wishes to thank the 
faculty of his "Alma Mater," Lehigh University, 
for their permission to use his Thesis on Alumin- 
ium as the basis of this treatise ; also, to acknowl- 
edge his indebtedness to Dr. Wm. H. Greene, of 
Philadelphia, for assistance rendered in the prep- 
aration of the work for the press. 

J. W. R. 

PHILADELPHIA, November 25, 1886. 


Tissier Recherche de 1' Aluminium. C. & H. 

Tissier. Paris, 1858. 
Deville De 1' Aluminium. H. St. Claire De- 

ville. Paris, 1859. 
Watts Watts' s Dictionary of Chemistry, 

vol. i. 
Mierzinski .... Die Fabrikation des Aluminiums. 

Dr. Mierzinski. Vienna, 1885. 
Compt. Rend. . . . Comptes Rendus de les Sciences de 

1'Academie. Paris. 
Wagner's Jahresb. . Wagner's Jahresbericht der Chem 

ische Technologic. 

Phil. Mag The London and Edinburgh Philo- 
sophical Magazine. 
Mon. Scientif. . . . Le Moniteur Scientifique. Dr. 

Fremy Encyclopedic Chemique. Fremy. 

Paris, 1883. 

Dingl. Joul Dingler's Polytechnisches Journal. 

Pogg. Ann Poggendorff''s Annalen. 

Jrnl. der Pharm. . . Journal der Pharmacie. 

Bull, de la Soc. Chem. Bulletin de la Soci6t6 Chemique de 


Sci. Am. (Suppl.) . . Scientific American (Supplement). 
Eng. and Mng. Jrnl. . The Engineering and Mining Journal. 
Chem. News . . . The Chemical News. 
Jahresb. der Chem. . Jahresbericht ueber die Fortschritte 

der Chemie. 


Al . . . . Aluminium. 

A1 2 O 3 . . . Alumina. 

A1 2 C1 6 . . . Aluminium chloride. 

K . . . . Potassium. 

KOH . . . Caustic Potash. 

KC1 . . . Potassium chloride. 

Na. . . . Sodium. 

Al 2 Cl 6 .2NaCl. Aluminium-sodium double chloride. 

Si ... . Silicon. 

Fe . . . . Iron. 

Cu . . . . Copper. 


Unless stated otherwise, all temperatures given are in Centi- 
grade degrees. 




Lavoisier's suggestion of the existence of metallic bases 
of the earths and alkalies ; Researches in preparation 
of aluminium, by Davy, Oerstedt, and Wohler . . 25 
Isolation of aluminium, by H. St. Claire Deville, in 1854 26 
Patronage of Emperor Napoleon III. ; Aluminium at the 
Paris Exhibition, 1855; Its manufacture on a large 
scale at Glaciere, Nanterre, and Salindres ; Tissier 
Bros.' book on aluminium in 1858 .... 28 
Deville' s book, 1859 ; History of the works near Rouen 29 
Deville's explanation of the uses of the new metal . 30 
Alfred Monnier's production of aluminium at Camden, 

N. J., 1856 31 ' 

W. J. Taylor claiming the possible cost of aluminium at 
1 per pound; Kerl and Stohman's rsum of the 
manufacture of aluminium up to 1874 ... 32 
Dr. Clemens Winckler's retrospect of the development of 

aluminium, 1879 33 

Manufacture of aluminium in England, France, and Ger- 
many ; Aluminium beams for balances, made by Sar- 
torius of Gottingen; Difficulties in using aluminium for 
mathematical instruments ; Action of molten aluminium 
upon earthen crucibles ...... 35 



Prices of aluminium and of aluminium bronze in France ; 
Webster's aluminium works in England . . .36 

Col. William Frishmuth's invention for producing alu- 
minium at reduced cost; Opinion of his invention by 
Major Ricarde-Seaver, F.R.S.E 37 

Col. Frishmuth's works in Philadelphia ; Aluminium cast- 
ing for the Washington Monument, made by Col. Frish- 
muth ; Census report of his annual production ; His 
price in bars ........ 39 

Imports and consumption of aluminium in the United 
States from 1870 to 1884 ; Its production in Philadel- 
phia by Col. Frishmuth in 1883, 1884 ... 40 

Cowle's process for making aluminium bronze at Cleve- 
land, Ohio ; Present state of aluminium industry as 
described by Prof. Charles F. Mabery, of Cleveland, 
Ohio, and Dr. T. Sterry Hunt, of Montreal . .41 


Combinations of aluminium with oxygen, alkalies, and 
acids, etc. ; Formulae of aluminium silicates . . 43 

Appearance of most of the aluminium compounds ; For- 
mulae of some of the precious stones .... 44 

Minerals most used for producing aluminium; Beauxite . 45 

Analyses of beauxite 46 

Cryolite ; Where found, description, and general uses ; 
Its importation by the Pennsylvania Salt Co., of Phila- 
delphia ; Native cryolite in the United States . . 48 

Imports of cryolite into the United States ; Corundum ; 
Its great source of supply 49 

Probable sources of supplies of materials for production 
of aluminium in the United States and Great Britain . 50 




Table of analyses of commercial aluminium ... 51 

Free and combined silicon in aluminium ; Gases in alu- 
minium ......... 52 

Composition of the aluminium apex of the Washington 
Monument at Washington, D. C., cast by Col. Frish- 
muth ; Color of aluminium ; As described by Deville, 
Fremy, Mallet, and Mierzinski ..... 53 

Mat ; As described by Deville, Mierzinski, and Bell Bros. 54 

Polish and lustre ; Processes for producing as given by 
Deville, Bell Bros, and Kerl and Stohman . . 55 

Odor ; As given by Deville and Watts .... 56 

Taste Deville; Malleability Deville and Mallet on this 
subject ......... 57 

M. Degousse's success in beating aluminium into leaves; 
Substitution of aluminium for silver leaf; Kerl & 
Stohman on rolling and annealing aluminium . . 58 

Bell Bros, on beating aluminium ; Mierzinski on extensi- 
bility of aluminium ....... 59 

Aluminium leaf first made by C. Falk & Co., Vienna; 
Ductility ; Drawing aluminium wire ; Results obtained 
by Deville, Vangeois, and Bell Bros. ... 60 

Elasticity, Tenacity, Hardness Deville, Wertheim, Mul- 
let, Fremy; Kerl & Stohman on engraving aluminium 61 

Mierzinski and W. H. Barlow on tensile strength; 
Tables ; Comparative mechanical value of aluminium, 
steel, etc 62 

Table of strength of aluminium wire; Sonorousness; Re- 
sults obtained by Deville and M. Lissajous in making 
bells and tuning-forks ...... 63 

Results obtained by Faraday and Watts ; Density ; De- 
ville' s table of comparison with other metals . . 64 



Comparative value of equal volumes of aluminium and 
silver ; Specific gravity of absolutely pure aluminium, 
Mallet ; Fusibility ; As given by Deville, Mallet, and 
Mierzinski ...... 65 

Fixity ; As given by Deville, Watts, and Fremy ; Elec- 
tric conductivity ; Results obtained by Deville and M. 
Buff , ... .66 

Comparison with copper and magnesium, Fremy ; Ther- 
mal conductivity; Deville, Faraday, and Watts, etc., 
on this subject . . . . . . . .67 

Mierzinski, Calvert, and Johnson on this subject ; Spe- 
cific heat ; Deville, Regnault, Paul Morin, Mallet, and 
Fremy on this subject 68 

Magnetism; Deville, MM. Poggendorff and Reiss ; Crys- 
talline Form ; Deville on this subject ... 69 


Remark; Action of air; Deville' s observations . . 70 
Cupellation of aluminium ; Observations of Wohler, Peli- 

got, Watts, etc. 71 

Action of water ; Deville on this subject . . .72 
Mierzinski and the Chemical News ; Action of hydro- 
gen sulphide and sulphur ; Deville and Fremy . . 73 
Sulphuric acid ; Deville, M. de la Rive, and Fremy . 74 
Nitric acid ; Deville and M. Hulot ; Hydrochloric acid ; 

Deville, M. Favre, and others ..... 75 
Potash, soda, and lime ; Deville, Mallet, Mierzinski . 77 
Aqua ammonia ; Deville and Wohler ; Organic acids, 
vinegar, etc. ; Deville, M. Paul Morin ; Use of Alu- 
minium for culinary articles ..... 78 
Solutions of metallic salts ; Precipitation of other metals 
by aluminium ; Deville, Tissier, Paul Morin, Mourey, 
Christofle, Hulot .79 



Mierzinski. Fremy and Watts 81 

Nitre ; Purification by nitre ; Deville, Fremy, and Mier- 
zinski on this subject 83 

Silicates and borates ; Action on glass and crucible clay ; 
Deville and Tissier ; Fluorspar ; Tissier on its use as 
a flux 84 

Phosphate of lime, Tissier on this subject ; Sodium chlo- 
ride and chlorides, Deville; Tissier on their use as 
fluxes 85 

Metallic oxides ; Tissier' s experiments .... 86 

Mierzinski ; Beketoff 's experiments ; Animal matters ; 
Deville and M. Charriere on the use of aluminium in 
surgery . . . . . . . . .87 

Miscellaneous agents; Tissier and Mierzinski on this 
subject .88 

General observations on the properties of aluminium, 
Deville 88 


.Oerstedt's original paper on isolation of aluminium, 1824 90 
AYohler, the true discoverer of the metal ; Wohler's first 

paper . .91 

Wohler's second paper ....... 93 

Deville' s remarks on the metal obtained by Wohler . 95 

Deville' s improvement, 1854-55 ..... 96 

Deville' s apparatus at Javel and Glaciere described and 

illustrated ......... 98 

Deville's experiments with sodium vapor . . . 100 
Reduction from cryolite ; H. Rose's entire paper . . 103 
Dr. Percy's investigations as laid before the Royal Insti- 
tution 115 

Allan Dick's paper, November, 1855 . . . .116 



Deville's account of his researches . . . .118 

Wohler's improvement on Deville's process; Watts on 

the reduction of cryolite ; Gerhard's furnace . .126 

Watts's summary of the use of cryolite . . .127 

General remarks . . . . . . .128 


Preliminary observations . . . . . .130 

Summary, taken principally from Mierzinski ; Efforts of 
Davy, Gay Lussac, Thenard, Curaudau, Brunner, 
Donny, and Mareska . . . . . .131 

Donny and Mareska's condenser, illustrated; Deville's 

account of its operation . . . . . . 132 

Object of and disadvantage in use of chalk ; Preliminary 
calcination of the mixture ; Illustration of the furnace. 133 

Decomposition retorts, illustrated 134 

Operation in the retorts . . . . . .135 

Deville, Rivot, and Tissier on the temperature . . 137 
Wagner's improvement; Attempts to reduce potassium 

and sodium together . . 138 

Weldon's calculation of the cost of sodium ; Making of 
sodium in New York City, N. Y. ; Castner's Ameri- 
can patent process . . . . .139 
Claims made in Castner's patent ... . 141 

Reduction of sodium by electricity, Mierzinski, Davy; 

Jablochoff's apparatus described and illustrated . . 142 


Present state of the industry ; Tilghman's process . . 144 
Manufacture from cryolite ; Dry way . . . . 146 



Thomson's furnace described and illustrated . . .147 
Preference for mechanical furnaces as used in manufac- 
ture of soda, potash, etc 148 

Precipitation of solution of sodium aluminate, according 

to Lowig 151 

Wet way 152 

Manufacture from alum-stone or shales . . . .153 



Preliminary remarks 154 

Mierzinski, Deville, and M. Dullo on this subject . . 155 
Manufacture by using hydrochloric acid and carbon di- 

sulphide 157 


Aluminium as made by A. R. Pechiney & Co., successors 

to Henry Merle & Co 158 

Reactions involved in and outline of the process . .158 
Preparation of the aluminate of soda ; Material used ; 
Composition of mixture ; Calcination, washing, filter- 
ing, with illustration of filtering apparatus . . . 159 
Preparation of the alumina ; Description of precipitating 
tank and method of precipitation, washing, and dry- 
ing, illustrated 163 

Preparation of aluminium sodium double chloride . 166 
Illustration of furnace ; Mixing and shaping the charge ; 
Condenser . . . . . . . .167 




Reduction of the double chloride by sodium ; Illustration 
of furnace ; Difficulties met ; Method of charging, re- 
ducing, and running out 168 

Average cost of manufacture at Salindres in 1872. . 172 
Later improvements in Deville's process ; Webster's pro- 
cess ; History and description of the plant ; Where its 
advantages lie ; Utilization of bye products . .173 
Frishmuth's process ; Patent claims . . . .178 
Other processes; Niewerth's method of reduction by nas- 
cent sodium ; Grousillier's reduction under pressure . 179 



Reduction by Cyanogen; Knowles's patent; Corbelli's 

patent 180 

Deville's and Watts' s comments ; Reduction by hydrogen ; 

Process of F. W. Gerhard; Comment by Watts . 181 
Reduction by carburetted hydrogen ; Process of A. L. 

Fleury, of Boston 182 

^Petitjean's process . . . . . . .183 

Reduction by double reaction ; Processes of M. Comenge 

and Johnson . . . . . . . . 1 84 

Process of Niewerth . . . . . . .185 

Reduction by carbon and carbon dioxide ; Process of J. 

Morris, of Uddington 187 

Reduction by carbon ; Article by M. Chapelle . .188 
Statement of G. W. Reinar ; Cowles Bros.' process . 189 

Patent claim of Messrs. Cowles 190 

Prof. Charles F. Mabery's official account of Cowles Bros.' 

process 191 

Dr. T. Sterry Hunt's paper read before the American 

Institute of Mining Engineers . . . . .194 



Dr. Hunt's address before the National Academy of 

Science 196 

W. P. Thompson's complete description of the process . 197 
Illustrative description of the furnace ; Mode of operat- 
ing furnace, and improvements thereon ; Amount re- 
duced ; Ores used 199 

Reduction by iron ; Lauterborn's process not new ; Pa- 
tents of F. Lauterborn and of H. Niewerth . . 206 
Preparation of aluminium and sodium in the Bessemer 

converter; W. P. Thompson's experiments . .207 
Calvert and Johnson's experiments .... 209 
Reports of Fremy, Watts, Benzon, Evrard . . .211 
Silicon bronze, by Evrard; Ostberg's statement of the 
iron-aluminium alloy used in the mitis process ; Re- 
duction with copper ; Calvert and Johnson's process . 212 
Kerl and Stohman's account of Benzon's process . .213 
Laboratory tests of this process ; Reduction by zinc ; 

Dullo's observations . . . . . . .214 

Patent of M. N. Basset 215 

Wedding's remarks on Basset's process . . .217 
Kagensbusch's singular proposition; Fred'k J. Seymour's 

patent 218 

Extraordinary claim in Seymour's second patent . . 220 
American Aluminium Co., Detroit; Reduction by lead; 

Wilde's invention 221 

Reduction by manganese ; Claims of W. Weldon, Bur- 
stow, England ; Reduction by electricity . . . 222 
Deville's account of the process ..... 223 
Sectional illustration of the crucibles .... 224 

Bunsen and Deville on the subject 225 

Mierzinski's practical remarks . . . . .226 
Patented improvement by Richard Gratzel, Germany, 

illustrated 228 

Duvivier's experiment with electric current . . . 229 



Kagensbusch's proposition ; Gaudin's " economic" reduc- 
tion of aluminium ....... 230 

Metals coated with aluminium by Thomas and Tilly ; 
Depositing of aluminium by Corbelli and J. B. 
Thompson 231 

Patented process by J. A. Jeancon ; Experiments by M. 
A. Bertrand, C. Winkler, and Sprague . . .232 

Electrolyses of M. L. Senet, Gerhard, and Smith ; De- 
composition of a solution of alum by J. Braun ; Moses 
G. Farmer's patent for obtaining aluminium . . 233 

Mierzinski's denial of the successful deposition of alu- 
minium from an aqueous solution of its salt ; Alumin- 
ium and nickel plating at Frishmuth's works . .234 


Melting aluminium ; Deville's instructions . . . 235 

Kerl and Stohman's instructions 236 

Mierzinski's instructions; Casting aluminium; Deville's 

instructions 237 

Purification of aluminium ; Freeing from slag, Deville . 238 

Process of Paul Morin 239 

Watts' s suggestion ; Freeing from impurities, Deville . 240 
Mierzinski's recommendation . . . . .242 

Buchner's treatment of commercial aluminium to elimi- 
nate silicon; Mallet's process of obtaining pure from 
commercial aluminium ; Uses of aluminium . . 243 
Aluminium plating and aluminium leaf . . . .246 
Aluminium coins ; Soldering aluminium ; Deville's 
views on . . . . . . . . .247 

Hulot's process ; Monrey's solder 248 

Mierzinski's statements as to Mourey's solder; Improve- 
ments of Schwarz ; Formulae for these solders . .249 



Frishmuth's solders; Kerl and Stohman on Mourey's 
solders, with formulae ...... 250 

Process of Bell Bros 252 

Veneering with aluminium; Deville's account of- the 

success of M. Sevrard in 1854 253 

Dr. Clemens Winckler on this subject . . . .254 
Gilding and silvering ahminium ; Failures of Deville 

and Morin ; Success of Mourey and Christofle . . 256 
Watts, and Kerl and Stohman, on this subject . .257 


General remarks, Mierzinski ..... 258 

Aluminium and silicon ; Tissier and Deville . . . 259 
Aluminium and mercury ; Statements of Deville and 

Watts ; Aluminium amalgam made by Caillet with the 

battery 261 

Joules' s method of electrolyzing 262 

Properties of aluminium amalgam ; Fremy, Tissier, 

Gmelin on this subject ...... 263 

Aluminium and copper; Tissier Bros., 18e8 . . . 264 
Deville, 1859 ; Use of the alloy by Christofle ; Alloy de- 
scribed by Debray ; Composition of aluminium bronze 265 
Properties of aluminium bronze ; M. Lechatelier's table 

of its strength ; Experiments by A. Gordon . . 266 
M. Boudaret on its malleability ; Mierzinski on points to 

be attended to in making the aluminium bronze . .267 
Directions to be observed in casting ; Comparative 

strength of the bronze 268 

Hulot's solder ; Fremy's instructions ; Kerl and Stohman's 

directions 269 

Bronze for philosophical instruments; Specific gravity 

and strength ; Comparative strength of the alloys ; 

Their specific gravities 270 



Melting point of 10 per cent, bronze ; B. S. Procter's ex- 
periments . . . . . . . . .271 

Thurston on the properties of aluminium bronze . . 272 
Strange and Knight on the properties of aluminium 

bronze 273 

Alloys made by Cowles Bros. 274 

Strength of these alloys by the testing machine . . 27G 
Alloys of aluminium and copper with other metals; 
Neogen made by F. H. Sauvage . . . .277 

Minargent ; P. Baudrin's alloy ; James Webster's 
patent bronze . . . . . . . .278 

Phosphor aluminium bronze made by Thomas Shaw, 
Newark, N. J.; Cowles Bros.' reports of the strength 
of aluminium silver castings ; Solders for aluminium 
bronze for jeweller's use ...... 279 

Silicon and aluminium bronze, Cowles Bros.; Aluminium 

and iron; Tissier Bros.' alloy; Deville, Rogers . 280 

Fremy and Mierzinski on aluminium alloys . . . 282 
Ostberg's mitis castings, with description of the process . 283 
Alloy used by Ostberg, Worcester, llass. . . . 285 

Ostberg's note to the Engineering and Mining Journal ; 

Watts's note; Mr. Sellers's series of experiments . 286 
Aluminium and zinc; Tissier Bros., Deville, Kerl and 
Stohman, and Fremy on these alloys . . . .287 

Aluminium and tin ; Tissier Bros., Deville, and Keii 
and Stohman on this subject ..... 289 

Fremy, Mierzinski, and M, Bourbouze . . . 290 

Aluminium and lead; Tissier, Deville, Kerl and Stohman, 
and Mierzinski . . . . . . . .291 

Aluminium and antimony ; Tissier, and Kerl and Stoh- 
man ; Aluminium and bismuth ; Tissier and Watts . 292 
Aluminium and nickel ; Tissier and Mierzinski . . 293 
Argentan .....'.... 294 

Minargent . . . 295 

Aluminium and silver ; Tissier on this subject . . 295 



Deville ; Kerl and Stohman ; Fremy .... 296 

Mierzinski ; "Tiers Argent;" Cowles Bros, on "Alu- 
minium silver" 297 

Aluminium and gold ; Tissier, Fremy, and Mierzinski 
on these alloys 298 

Aluminium and platinum ; Tissier ; Aluminium and Cad- 
mium, Deville; Aluminium and boron, Deville on this 
subject 299 

Aluminium and carbon, Deville and Cowles ; Aluminium 
and gallium, Watts, Lecoq de Boisbaudran . .300 

Aluminium and titanium, TVohler 301 

Aluminium and tungsten, by Michel, in Wb'hler's labora- 
tory ; Aluminium and molybdenum ; Experiments by 
Michel; Aluminium and manganese ; Experiments by 
Michel 302 

Aluminium and sodium ; Deville and Fremy on these 
alloys ; Aluminium and nitrogen, Dr. Hunt . . 303 


Native sulphate of alumina ; Account of a deposit in 

New Mexico 305 

Decomposition of cryolite; F. Lauterborn's patent; 

American aluminium ; Frishmuth's metal . . . 306 
Analyses of same ; Specific gravity of aluminium ; Gravity 
calculated from analyses ...... 307 

Amalgamation of aluminium ...... 308 

Theory of the rapid oxidation of aluminium amalgam ; 
Reduction of alumina ; Experiment on reduction with 
copper; Production and reduction of aluminium sul- 
phide ; Fremy 's researches ..... 309 

Investigations by Reichel . . . . . .312 

Than's remarks 314 

Reichel's experiments in reducing aluminium sulphide ; 
Petitjean's patent . . . . . . 315 



Reich el* 8 summary . . . . . . .316 

Aluminium chloride formed from the sulphide ; F. Laut- 
erborn-'s patent 317 

Niewerth ; Reichel ; A. Orlowski ; Experiments on mak- 
ing aluminium sulphide . . . . . .318 

Tabulated results ; Remarks and suggestions of a practical 
process 321 

Reducing the aluminium sulphide 322 

Experiments with lead, copper, tin, antimony, and iron ; 
Review of these experiments and suggestions of a prac- 

, tical process 323 


Additional details of Castner's sodium process . .324 
New process for making aluminium chloride ; Remarks on 

the mitis process . . . . . . .326 

Production of aluminium in 1885; Low price of aluminium 

in October, 1886 327 

INDEX 328 




LAVOISIER* first suggested the existence of metal- 
lic bases of the earths and alkalies. The first 
researches in the preparation of aluminium date 
back to 1807. Davy tried, but in vain, to decom- 
pose A1 2 8 by an electric current, or to reduce it 
by vapor of potassium. Oerstedt, in 1824, believed 
he had isolated aluminium. He decomposed anhy- 
drous A1 2 C1 6 by K amalgam, and he obtained, 
along with some KC1, an amalgam which decom- 
posed by heat furnished him a metal resembling 
tin. It is probable that he employed either some 
moist APC1 6 or K amalgam which contained KOH, 
for it is only when wetted with a solution of KOH 
that aluminium alloys with mercury; for, when 
AVohler, later, wished to prepare aluminium by 
this method, he found it impossible to obtain an 
Al amalgam when he employed materials pure 

* Fremy, Ency. 


and dry. Nevertheless, the method of Oerstedt 
marks an epoch in the history of the science, for 
in 1827 Wohler isolated aluminium by decomposing 
APC1 6 by K. The metal first isolated by Wohler 
was a gray powder, taking under the polisher the 
brilliancy of tin. It was very easily changed, 
because of its extreme division, and also because 
it was mixed with the K or A1 2 C1 6 used in excess. 
At that time no further use was made of these 
facts. Later, in 1845, on making vapor of AP01 6 
pass over potassium placed in platinum boats, 
Wohler obtained the metal in small, malleable 
globules of metallic appearance, from which he 
was able to determine the principal properties of 
aluminium. But the metal thus obtained was 
scarcely as fusible as cast iron, without doubt 
because of the platinum with which it had alloyed 
during its preparation. In addition to this, it 
decomposed water at 100, from which we suppose 
that it was still impregnated with K or APC1 6 . It 
is to H. St. Claire Devil le that the honor belongs 


of having in 1854 isolated aluminium in a state of 
almost perfect purity, determining its true proper- 
ties. In commencing researches on aluminium, 
Deville, while he applied the method of Wohler, 
was ignorant of the latter's results of 1845. Besides, 
he was not seeking to produce aluminium that he 
might turn its valuable properties to practical ac- 
count, but that it might serve for the production 
of A10, which he believed could exist as well as 


FeO. The aluminium he wished to prepare would, 
he thought, by its further reaction on APC1 6 form 
A1C1 2 , from which he might derive A1O and the 
other proto-salts. But this proto-chloride was not 

thus produced ; he obtained, enclosed in a mass of 

A1 2 C1 6 .2KC1, fine globules of a brilliant substance, - 
ductile, malleable, and very light, capable of being 
melted in a muffle without oxidizing, attacked 
by H^TO 3 with difficulty, but dissolved easily by 
HC1 or KOH with evolution of hydrogen. Recog- 
nizing the importance of these properties, which 
he proceeded to investigate and establish, and 
fearing to see the honor of his discovery pass into 
other hands, Deville immediately commenced 
research for an economic process to produce alumi- 
nium. The task was difficult, for the metal could 
only be isolated from its chloride or fluoride by ~ 
potassium or sodium, of which only the former 
was known at that time. Moreover, potassium I 
cost then 900 fr. per kilo, was extremely dangerous, 
and gave only a small return of aluminium. 
Deville succeeded in advantageously replacing \ 
potassium by sodium, and introduced such im- 
provements into the manufacture of the latter that 
he reduced the cost of a kilo from 2000 fr. in 1855 
to 10 fr. in 1859. In order to produce aluminium 
cheaply, he busied himself also in the economic 
production of A1 2 3 , which gave later a lively 
impulse to the cryolite and beauxite industries. 
The researches of Deville, at first undertaken in I 


the laboratory of the Normal School, Paris, were 
afterwards continued on a larger scale, thanks to 
the liberality of the Emperor Napoleon III., at 
the chemical works of Javel. At this works were 
made the ingots and divers objects of aluminium 
which figured at the Paris Exhibition in 1855. 
Later, after new experiments made together at the 
Normal School, Deville, H. Debray, and P. Morin 
set up a plant to make aluminium on a large scale 
at Messrs. Rousseau Brothers' works at Glaciere. 
The primary method there received many improve- 
ments. Later on it was still further improved 
under the direction of P. Morin at the works in 
Nanterre. At last, in the works of Messrs. Merle 
& Co., at Salindres, it has reached its present stage 
^of advancement. 

Tissier Bros, wrote and published a book entitled 
' Recherches sur 1'Aluminium' in 1858. These 
brothers were employed in the experiments which 
Deville superintended at the laboratory of the 
Normal School, Paris, and Deville charges that 
after learning the important results of his experi- 
ments they suddenly left him, taking drawings of 
furnaces, details of processes, etc., and started works 
themselves. Deville was very bitter against them, 
and this ill-feeling was increased by the following 
incident : Deville was collecting material to write 
a book on the subject, which he almost regarded as 
his prerogative, seeing that he had, so to speak, 
created the industry ; but, before he had completed 


it, Tissier Bros, published theirs. In order not to 
be too far behind, Deville hastened the comple- 
tion of his book, by doing which he was unable 
to make it as full as he had wished, and published 
it in September, 1859. Several sharp letters passed 
between Deville and the Tissiers, which may be 
seen in the Compt. Rend, or Ann. de Chem. et de 
Fhys. A. Tissier, in his book, thus describes the 
formation and history of his works : In July, 1855, 
Messrs. Maletra, Chanu, and Davey, of Rouen, 
formed a company to produce aluminium, and we 
were entrusted with the organization and special 
charge of the industry. The commencement was 
beset with difficulties, not only in producing, but 
in using the metal. It then sold at 200 per kilo, 
the price being an insurmountable obstacle to its 
employment in the arts. The small capital at our 
disposal was not enough to start the industry, to 
pay general expenses, and the losses occasioned by 
the many experiments necessary. On February 
28, 1856, the society was dissolved. In April, the 
same year, Mr. William Martin, struck by the 
results already obtained, and sanguine of greater 
success, united with us. From that time daily 
improvements confirmed M. Martin's hopes, and 
in 1857 the works at Amfreville-la-mi-Voie, near 
Rouen, sold the metal at 60 per" kilo (2.00 per 
oz.). The laboratory of this works was devoted 
to researches on everything concerning the produc- 
tion and application of aluminium. M. Martin 



has our sincere gratitude for the kindness with 
which he so willingly encouraged and contributed 
to the progress of the manufacture of "this won- 
derful metal." 

Deville, as stated above, published his book in 
September, 1859, and he concludes it with these 
words : " I have tried to show that aluminium may 
become a useful metal by studying with care its 
physical and chemical properties, and showing the 
actual state of its manufacture. As to the place 
which it may occupy in qur daily life, that will 
depend on the public's estimation of it and its 
commercial price. The introduction of a new 
metal into the usages of man's life is an operation 
of extreme difficulty. At first, aluminium was 
spoken of too highly in some publications, which 
made it out to be a precious metal ; but later these 
estimates have depreciated even to the point of 
considering it attackable by pure water. The 
cause of this is the desire which many have to see 
taken out of common field mud a metal superior 
to silver itself; the opposite opinion established 
itself because of very impure specimens of the 
metal which were put in circulation. It seems 
now that the intermediate opinion, that which I 
have always held and which I express in the firsf 
lines of my book, is becoming more public, and 
will stop the illusions and exaggerated beliefs 
which can only be prejudicial to the adoption of 
aluminium as a useful metal. Moreover, the in- 


dustry, established as it now is, can be the cause 
of loss to no one ; as for myself, I take no account 
of the large part of my estate which I have devoted, 
but am only too happy, if my efforts are crowned 
with definite success, in having made fruitful the 
work of a man whom I am pleased to call my 
friend the illustrious Wohler." 

As early as 1856 we find an article in an Ameri- 
can magazine* showing that there were already 
chemists in the United States spending time and 
money on this subject. The following is the sub- 
stance of the article alluded to: "Within the 
last two years Deville has extracted 50 to 60 Ibs. 
of aluminium. At the present time, M. Rousseau, 
the successor of Deville in this manufacture, pro- 
duces aluminium which he sells at 100 per pound. 
Xo one in the United States has undertaken to 
make the metal until recently Mons. Alfred Mon- 
nier, of Camden, X. J., has, according to the 
statement of Prof. James C. Booth in the c Penn. 
Inquirer/ been successful in making sodium by a 
continuous process, so as to procure it in large bars, 
and has made aluminium in considerable quantity, 
specimens of which he has exhibited to the Frank- 
lin Institute. Mons. Monnier is desirous of forming 
a company for tjie manufacture of aluminium, and 
is confident that by operating in a large way he 
can produce it at a much less cost than has hereto- 

* Mining Magazine, 1856, vii. 317. 


fore been realized. We would suggest the pro- 
priety of giving aid to this manufacturer at the 
expense of the government, for the introduction of 
a new metal into the arts is a matter of national 
importance, and no one can yet realize the various 
and innumerable uses to which this new metal may 
be applied. It would be quite proper and consti- 
tutional for Congress to appropriate a sum of 
money, to be expended under the direction of the 
Secretary of the Treasury in the improvement of 
this branch of metallurgy, and in testing the value 
of the metal for coinage and other public use." 

In the next volume of the ' Mining Magazine'* 
there is a long article by Mr. W. J. Taylor, con- 
taining nothing new in regard to the metallurgy 
of aluminium, but chiefly concerned in calculating 
theoretically the cost of the metal from the raw 
materials and labor required by Deville's processes, 
and concluding that it is quite possible to make it 
for $1,00 per pound. 

In 1874 we have the following resume by Kerl & 
Stohman : " Deville first worked under the direc- 
tion of the Paris Academy ; later, the Emperor 
Napoleon gave him great encouragement, by means 
of which he succeeded in producing several kilos 
of aluminium, which were shown at the exhibition 
in Paris, 1855. With the experience thus gained, 
Deville took possession of Rousseau Bros.' cherni- 

* Mining Magazine, viii. 167 and 228. Proc. Ac. Nat. Sci., 
Jan. 1857. 


cal works at La Glaciere, near Paris. It soon fol- 
lowed that the price of aluminium was reduced 
from 1000 fr. per kilo to 300 fr. After a short 
time the undertaking was enlarged, and the manu- 
facture removed to Nanterre and Salindres. The 
last named works, under the management of 
Usiglio, went into the possession of Merle. !N"ew 
advances made a further reduction in price to 
200 fr. possible. In 1862 the price was put down 
to 130 fr. Another works was then established at 
Amfrcville, near Rouen. This was on a larger 
scale than that at Kauterre, for while in 1859 the 
latter produced 60 kilos, the former produced 80. 
In England the first manufactory was established in 
1859, at Battersea, London ; and the next year Bell 
Bros, started at Kewcastle-on-Tyne. Germany as 
yet possesses no aluminium works." 

The further we get away from an age the better 
able are we to write the true history of that age. 
And so, as years pass since the labors of AVohler, 
Deville, and Tissier, we are now able to see better 
the whole connected history of the development 
of this art. Dr. Clemens Winckler gives us a 
comprehensive retrospect of the field seen from the 
standpoint of 1879, from which we condense the fol- 
lowing :* The history of the art of working in alu- 
minium is a very short one, so short that the present 
generation, with which it is contemporary, is in 

* Industrie Blatter, 1879 ; Sci. Am. Suppl., Sept. G, 1879. 


danger of overlooking it altogether. The three 
international exhibitions which have been held in 
Paris since aluminium first began to be made on a 
commercial scale form so many memorials of its 
career, giving, as they did, at almost equal intervals, 
evidence of the progress made in its application. 
In 1855, we meet for the first time, in the Palais de 
1'Industrie, with a large bar of the wonderful 
metal, docketed with the extravagant name of the 
" silver from clay." In 1867 we meet with it 
again, worked up in various forms, and get a view 
of the many difficulties which had to be overcome 
in producing it on a large scale, purifying, and 
moulding it. We find it present as sheets, wire, 
foil, or worked-up goods, polished, engraved, and 
soldered, and see for the first time its most impor- 
tant alloy aluminium bronze. After a lapse of 
almost another dozen years we see at the Paris 
exhibition of 1878 the maturity of the industry. 
"We have passed out of the epoch in which the 
metal was worked up in single specimens, showing 
only the future capabilities of the metal, and we 
see it accepted as a current manufacture, having a 
regular supply and demand and being in some 
regards commercially complete. The despair which 
has been indulged in as to the future of the metal 
is thus seen to have been premature. The manu- 
facture of aluminium and goods made of it has 
certainly not taken the extension at first hoped 
for in its behalf; the lowest limit of the cost of 


manufacture was soon reached, and aluminium 
remains as a metal won by expensive operations 
from the cheapest of raw materials. 

To France is due the merit of having been the 
first country to carry out Wohler's process on a 
practical scale, and to have created the aluminium 
industry. France seems to be the only country in 
which the industry is able to prosper. The English 
establishment at Newcastle-on-Tyne by Bell & Co. 
did not succeed, and has been shut up now for 
about live years. The German manufactory, set 
up in Berlin by Wirz & Co., cannot be said really 
to have lived at all ; it drooped before it was well 
started. In France, the great chemical works of 
H. Merle & Co., Salindres, carries on the extraction 
of aluminium, and the Societe Anonyme de 1'Alu- 
rninium, at Nanterre, works up the metal. Both 
firms were represented at the exhibition in 1878. 

The most rational use indicated for aluminium 
by reason of its low specific gravity is the making 
of beams for balances. Sartorius, of Gottingen, 
was the first to make these light and unalterable 
beams of an alloy of 96 aluminium and 4 silver. 
He has had but few imitators. There are several 
reasons why the metal is shown so little favor by 
mathematical instrument makers and others. First 
of all, there is the price ; then the methods of 
working it are not everywhere known ; and further, 
no one knows how to cast it. Molten aluminium 
attacks the common earthen crucible, reduces silicon 


from it, and becomes gray and brittle. This incon- 
venience is overcome by using Jirne crucibles, or 
by lining an earthen crucible with carbon or strongly 
burnt cryolite clay. If any one would take up the 
casting of aluminium and bring it into vogue as a 
current industrial operation, there is no doubt that 
the metal would be more freely used in the finer 
branches of practical mechanics. The prices per 
kilo quoted in the last list issued by the Societe 
Anonyme are as follows : 


Bars 130 fr. 

Sheets (0.5 to 0.1 mm. thick) . 135 " to 160 fr. 

Wire (2 to 3 mm. diam.) . . 170 " " 200 " 

ALUMINIUM BRONZE (10 per cent, aluminium). 

Bars 18 fr. 

Sheets (2 to 0.5 mm. thick) . . 24 " to 30 fr. 
Wire (7 to 1 mm. diam.) . . . 28 " to 39 " 

The preceding paper of Dr. Winckler, as he re- 
marks, chronicles the perfection of Deville's pro- 
cesses, when aluminium was made as cheaply 
as it could possibly be by these methods. But, 
about this time an aluminium works was started 
in Birmingham, England, by Mr. Webster, which 
has grown to be one of the largest in the world. 
Mr. Webster owns several patents on processes of 
his own, which will be found described in their 
proper places. 

In the United States one of the most prominent 


chemists engaged on aluminium is Colonel William 
Frishmuth, of Philadelphia. The following article 
gives an account of his invention :* " Some months 
ago, we published in the ' Star 7 the fact that Colonel 
"William Frishmuth, well known in this city for 
many years, has discovered a method for producing 
aluminium at reduced cost. Comments were made 
in various quarters as to the real value of the discov- 
ery, some of which even questioned the possibility 
of producing the metal by this process, which is 
stated to produce it from South Carolina corundum, 
using sodium as a reagent. Meanwhile patents 
have been taken out in this and foreign countries, 
and preliminaries are fairly under way to test the 
process practically. It did not seem too much to 
hope when the publication was made that Ameri- 
can capitalists would at once make investigation of 
Colonel Frishmuth's discovery, learn whether the 
results were even measurably up to the promise, 
and in that event secure to themselves a commercial 
plant so extremely important. It has, however, 
fallen to capitalists abroad to obtain control of the 
patent. At the present time Major Ricarde-Seaver, 
F.R.S.E., late Government Inspector of Mines, 
London, is in this city as an expert to examine the 
process and its practicability on behalf of these 
capitalists. A reporter endeavored to obtain from 
Major Seaver his opinion of the process, but he 

* Philadelphia Evening Star, November 15, 1884. 



stated that his opinion could not be made public. 
Mr. Seaver said in reference to aluminium : ' Some 
of the best minds in Europe have been studying 
for years the problem of producing the metal 
cheaply. Scientists in France and Germany and one 
in Geneva have been at work on it a long time. 
As to the possibility of producing it so that it 
could be used as an alloy for iron and steel, that is not 
to be expected unless it could be produced at much 
less than a dollar per pound. As to the possibility 
of doing that by this process, I am not at liberty 
to speak. The work here has so far been merely 
on an experimental scale. As scientific men know 
by many experiences, disappointments are some- 
times met with when they leave the experimental 
field and work is attempted on a commercial scale 
for business purposes. I am, however, very much 
pleased with what I have seen here, and, as I have 
said, while scientific men all over Europe have been 
investigating the problem, it seems to be solved 
here. I am certainly satisfied that aluminium can 
be produced by Frishmuth's process, there is some 
metal made by it, and there will be a display of it 
at the NQW Orleans exhibition. Even if it can be 
made very cheap by this process, it is not probable 
that anything more would be done by the parties I 
represent than to supply the market at a fair price, 
just as the Rothschilds, who own the great quick- 
silver mines of the world, regulate the supply by 
the demand.' " 


Colonel Frishmuth's works are at Rush and 
Amber streets, near the Richmond coal wharves, 
Philadelphia. lie seems to be kept busy, and his 
metal is on the market ; an analysis of it will be found 
in the Appendix. It can be bought from Bullock 
& Crenshaw, Philadelphia. He cast the tip of the 
AVashington Monument, which weighs one hundred 
ounces, one of the largest single castings of alumin- 
ium ever made. As far as is known, he is at pres- 
ent the only producer of pure aluminium in the 
United States. His metal is sold in bars at about 
fifteen dollars per pound. In the Philadelphia city 
census of 1884 he is placed as employing ten men, 
and his annual product is valued at 18,000. Mr. 
Frishmuth melts down quantities of aluminium 
scrap, and the author has been unable to learn, ex- 
cept from Mr. Seaver's statement, that Mr. Frish- 
muth produces any aluminium by his process. Mr. 
Seaver represented an English syndicate which 
stands ready to buy out all patents of any value 
which appear on aluminium ; they possess large 
capital, and are said to be ready to pay an immense 
sum for any practical, cheap process for producing 
the metal. 

In the Mineral Resources of the United States, 
1883-4, we find a few statistics as to the amount 
of aluminium made in recent years. It is there 
stated that in 1882 there were 2350 kilos made in 
France. The price of the American metal ranged 
from 0.75 to 1.00 per troy ounce in 1883 ; and 


from $0.50 to $1.00 per ounce in 1884, according 
to quantity. The amount imported and entered for 
consumption in the United States from 1870 to 1884 
is as follows : 

Year ending June 30, 

Quantity (pounds). 


1870 . 

$ 98 






1873 . 




. 683 


1875 . 

. 434 


1876 . 

. . .139 



. 131 


1878 . 

. 251 



. 284 



. 341 


1881 . . . 

. 517 


1882 . 

. 566 



. 436 


1884' . 

. 590 


Until recently the aluminum sold in the United 
States was entirely of foreign origin, but it is now 
produced in this country by Colonel Frishmuth, 
of Philadelphia, who turned out 1000 ounces of 
the metal in 1883, and 1800 ounces in 1884. The 
aluminium cap or apex of the Washington Monu- 
ment was cast by him ; it is of pyramidal form, 
10 inches high, 6 inches on a side of its base, and 
weighs 8J pounds (see p. 53). 

Within the last two years a process has been 
invented and brought into practical use which has 
served to bring the metallurgy of aluminium into 


very general attention. The Cowles' process, the 
discovery and details of which will be given further 
on, is due to two Cleveland gentlemen, and they 
seem to be developing all that is in their process. 
They make no pure metal, but sell the alloys, 
principally aluminium bronze, the latter of good 
quality, and at a much lower price than it was 
ever sold before. If they can make it profitable 
to sell the bronze at the price which they now 
quote, the permanent success of their process is 
assured. Mr. Charles F. Mabery, of the Case 
School of Applied Science, Cleveland, is their con- 
sulting chemist, and Dr. T. Sterry Hunt, of Mon- 
treal, seems to be very much interested in the pro- 
cess from a scientific point of view. Mr. Mabery 
gives his views as to the present state of the alumi- 
nium industry as follows: "The aluminium of 
commerce has been made chiefly in France by 
Deville's old method. Several patents have been 
issued for its prod uction by electrolysis, and although 
it can be deposited in small quantities from solu- 
tions, there is but one electrolytic method that 
can be worked on a commercial basis, and that is 
Bunsen & Deville's method of electrolysing molten 
Al 2 Cl 6 .2XaCl. Large works have recently been 
erected in France for obtaining the metal by this 
method, and it is claimed that it can be produced 
for about $7 per pound. A company has recently 
been formed in London to manufacture aluminium 
alloys on the basis of the Webster patents. The 



chief improvement on the old process, according 
to the patent specifications, is in the preparation of 
the pure A1 2 3 . Frishmuth, of Philadelphia, 
attempts to produce sodium in one retort, volatilize 
aluminium chloride from another, and allow the 
vapors to meet in a third. The assertion made by 
him at first that he could place the metal on the 
market at $1.25 per pound has not been verified." 
Dr. Hunt, in reply to an inquiry as to the present 
state of the industry, replies : " Webster, of Eng- 
land, is the chief, perhaps the only, manufacturer 
in that country of the metal and its alloys. Messrs. 
Cowles manufacture the alloys, and they can now 
make pure aluminium, but the method is not yet 
perfected or made public. The process of Frish- 
muth is not new, but is mentioned in Watts' Dic- 
tionary. So far as I can learn, and so far as Messrs. 
Cowles are informed, there has been no pure alu- 
minium made commercially save from the chloride 
by use of sodium. Messrs. Cowles' work with 
their large new dynamo has been very satisfac- 



THERE is no other metal on the earth which is 
so widely scattered and occurs in such abundance. 

Al is not found metallic. Stocker* made the 
statement that Al occurred as shining scales in an 
alumina formation at St. Austel, near Cornwall, 
but he was in error. But the combinations of Al 
with oxygen, the alkalies, fluorine, silicon, and 
the acids, etc., are so numerous and occur so abun- 
dantly as not only to form mountain masses, but to 
be also the bases of soils and clays. Especially 
numerous are the combinations with Si and other 
bases, which, in the form of felspar and mica, 
mixed with quartz, form granite. Mierzinski 
gives the formulae of a few of these silicates as: 

Orthoclase . . K 2 Si 3 O" + 

Albite . . . Na 2 Si3O 7 + Al 2 Si 3 O 9 

Anorthite . . CaSiOS-f Al 2 SiO 5 

K Mica . . (HK)*Al*Si*08+ (HK) 2 Al 2 Si 4 O'5 

Na Mica . . (HNa) 2 Al 2 Si 2 O 8 -f- (HNa) 2 Al 2 Si 4 O 

Li Mica . . (Li^KXFe^.AlWSSiO 2 . 

Mg Mica . . m(HK) 4 SiO 4 -f-n(Mg.Fe.H.) 2 SiO 4 -f 

* Jrnl. fr. prakt. Chenu, 06, 470. 


These combinations, by the influence of the 
atmosphere, air, and water, are decomposed, the 
alkali is replaced or carried away, and the residues 
form clays. The clays form soils, and thus the 
surface of the earth becomes porous to water and 
fruitful. It is a curious fact that Al has never 
been found in animals or plants, which would seem 
to show that it is not necessary to their growth, 
and perhaps would act injuriously, if it were present, 
by its influence on the other materials. Most of the 
Al compounds appear dull and disagreeable, such 
as felspar, mica, pigments, gneiss, amphibole, por- 
phyry, eurite, trachyte, etc. ; yet there are others 
possessing extraordinary lustre, and so beautiful as 
to be classed as precious stones. Some of these, 
with their formulae, are 

Ruby . . . . A1 2 Q3 

Sapphire . . . A1 2 O 3 

Garnet .... (Ca.Mg.Fe.Mn)3Al 2 Si 3 Oi2 

Cyanite . . . APSiO 5 

Some other compounds occurring frequently 

Turquoise . . . A1 2 P 2 O 8 .H6A1 2 O 6 .2H 2 

Lazulite . . . (MgFe)Al 2 P 2 O9 + Aq 

Wavellite . . . 2A1 2 P 2 O 8 .H6AK) 5 .9H 2 O 

Topaz .... 5Al 2 SiO 5 .Al 2 SiF 10 

Cryolite . . . Al 2 F 3 .6NaF 

Diaspore . . . H 2 A1 2 O 4 

Beauxite . . . H 6 A1 2 O 6 

Aluminite . . . A1 2 SO 6 .9H 2 O 

Aluuite K*SO 4 .A1*S 3 12 .2H 2 AKO 3 


One would suppose that since aluminium occurs 
in such ahundance over the whole earth, since we 
literally tread it under foot, that it would he ex- 
tracted and applied to numberless uses, being 
made as abundant and useful as iron ; but such is 
not the case. 

Beauxite and cryolite are the minerals most 
used for producing aluminium, and their preference 
lies mainly in their purity. Native alums gene- 
rally contain Fe, which must be removed by ex- 
pensive processes. Some observations on a native 
alum deposited in New Mexico will be found in 
the Appendix. WQ will here consider at greater 
length only beauxite and cryolite. 


Beauxite is a combination between diaspor, 
A1 2 3 .3H 2 0, and brown hematite, Fe*0.3EPO ; or, 
it is diaspor with Al replaced more or less by Fe ; 
the larger the amount of Fe the more its color 
changes from white to brown. It was first found 
in France, near the town of Beaux, large deposits 
occurring in the departments Yar and Benches du 
Rhon, extending from Tarascon to Antibes. Seve- 
ral of these beds are a dozen yards thick, and . 160 
kilometres in length. Deposits are also found in 
the departments of 1'Herault and 1'Arriege. Very 
important beds are found in Styria, at Wochein, 
and at Freibriss, in Austria, a newly discovered 



locality where the mineral is called Wochehrite. 
Here it has a dense, earthy structure, while that of 
France is conglomerate or oolitic. Deposits similar 
to those of France are found in Ireland at Irish 
Hill, Straid, and Glenravel. Further deposits are 
found in Hadamar in Hesse, at Klein-Steinheim, 
Langsdorff, and in French Guiana. 

The following analyses give an idea of the pecu- 
liar composition of this mineral ; besides the in- 
gredients given there are also traces of CaO, MgO, 
SO 3 , P 2 5 , TiO 2 , and Ya 2 3 . 







A1 2 O 3 . . . 







Fe 2 O 3 . . . 







SiO 2 . . . 







K*0 and Na 2 O 







H 2 ... 













A1 2 O 3 . . . 
Fe 2 O 3 . . . 
SiO 2 . . . 
K 2 O and Na 2 O 








H 2 . . . 













A1 2 3 . . . 






FC2O 3 . . . 






SiO 2 . . . 






K 2 O and Na 2 O 



H 2 ... 







Index : 
a and b. from Beaux (Deville). 

c. dark \ Woclieinite (Drechsler). 

d. light J 

e. red brown \ 

f. yellow > Beauxite from Feisstritz (Schnitzer). 

g. white 

h. white Wocheinite (L. Mayer and O. Wagner). 

*. Beauxite from Irish Hill. 

k. " " Co. Antrine (Spruce). 

I " " Glenravel (F. Hodges). 

raandw. " " Hadamar (Hesse) (Retzlaff). 

o. from Klein-Steinheim (Bischof ). 

p and q. from LangsdorfF (I. Lang). 

r. Beauxite from Dublin, Ireland, brought to the Laurel 

Hill Chemical Works, Brooklyn, L. I., and there 
used for making alums. It is dirty white, hard, 
dense, compact, and in addition to the ingredients 
given above contains 0.59 percent. CaO, and some 
TiO 2 . It costs $6 per ton laid down in the works. 
The above analysis, made by Mr. Joiiet, is fur- 
nished me by the kindness of the superintendent 
of the works, Mr. Herreshoff. 

As is seen from the above analyses, the percentage 
of A1 2 3 is very variable, and cannot be determined 
at all simply by inspection but only by an analysis, 
for often- the best-looking specimens are the lowest 
in APO 3 . For instance, a beauxite containing 62.10 
A1 2 3 , 6.11 Fe 2 3 , 5.06 SiO 2 , and 20.83 H*0 was 
much darker and more impure looking than that 
from Wochein (h) which contained only 29.8 per 
cent. APO 3 . 



Cryolite was first found at Ivigtuk, in Arksut- 
fiord, west coast of Greenland, where it constitutes 
a large bed or vein in gneiss. It is a semi-trans- 
parent, snow-white mineral. When impure it is 
yellowish or reddish, even sometimes almost black. 
It is shining, sp. gr. 2.95, and hardness 2.5 to 3. 
It is brittle, not infrequently contains FeCO 3 , PbS, 
SiO 2 , and sometimes columbite. It is fusible in 
the flame of a candle, and on treatment with sul- 
phuric acid yields hydrofluoric acid. As will be 
seen further on, cryolite was first used by the soap- 
makers for its soda; it is still used for making soda 
and alumina salts,.and to make a white glass which 
is a very good imitation of porcelain. The Penn- 
sylvania Salt Company in Philadelphia import it 
from Ivigtuk by the ship-load for these purposes ; 
lately they have discontinued making the glass. 
Cryolite is in general use as a flux. A very com- 
plete description of the deposit at Ivigtuk can be 
found in Hoffman's ' Chemische Industrie.' 

The only known deposit of cryolite in the United 
States is that found near Pike's Peak, Colorado, 
and described by W. Cross and W. F. Hillebrand 
in the ' American Journal of Science,' October, 
1883. It is purely of mineralogical importance 
and interest, occurring in small masses as a sub- 
ordinate constituent in certain quartz and feld- 
spar veins in a country rock of coarse reddish 


granite. Zircon, astrophyllite, and columbite are 
the primary associated minerals, the first only 
being abundant. 

There -is no duty on the imports of cryolite into 
the United States, and they have varied from 
10,000 tons in 1869 to 9000 in 1884, costing $9 to 
$10 per ton. 


" Till 1869, the sole sources of corundum were 
a few river washings in India and elsewhere. 
It was found in scattered crystals, and cost twelve 
to twenty-five cents per pound. In 1869, in 
riding over a spur of the Alleghenies in northern 
Georgia, I* found what has proven to be an 
almost inexhaustible mine of corundum in the 
crysolite serpentine, the first instance on record of 
the mineral being found in situ. Previously it had 
been washed out of debris at Cripp's Hill, N". C., 
and at a mine in West Chester, Pa., both on the 
slopes of the crysolite serpentine. The clue being 
thus obtained accidentally, about thirty mines were 
shortly afterwards discovered in the same forma- 
tion ; but of the thousands of tons thus far dug 
out, the larger portion has come from the mines I 

" At present it can be bought at about ten dollars 
per ton at the mines. It is nearly pure A1 2 O 3 . 

. W. P. Thompson. 


Disapore, a hydrated alumina, is also found in the 
same region and locality. Corundum will proba- 
bly always be the principal source in America of 
material from which to manufacture pure Al. 
But in Great Britain, in all probability, manufac- 
turers must look to alumina prepared artificially 
from cryolite or from Mr. Kynaston's sulphate of 

* Journal of the Society of Chemical Industry, April, 1886. 



COMMERCIAL aluminium is never chemically pure, 
and therefore displays properties varying more or 
less from those of the pure metal according to the 
character and amount of impurities present. In 
this treatise, whenever the properties of aluminium 
are mentioned, they must be understood to refer to 
the chemically pure metal, and not to the commer- 
cial article, unless specifically stated. As prelimi- 
nary to the presentation of these properties we will 
here make some observations on the commercial 
metal and the impurities generally found in it. 

In whatever way aluminium may be reduced, 
still it is always far from being pure, being con- 
taminated with iron, silicon, or even sodium and 
lead, as is shown by the following analyses : 







A r a. 

1 Parisian (Salvetat) . ... 










o' * Berlin (Mallet) 

4. Mo fin & Co., Nanterre (Sauerwein) . 
**' [ Parisian (Dumas) 

7. Parisian (Salvetat) ... ... 

9 Bonn (Kraut) . ... . . 

}} j Morin & Co., Nanterre, 1862 (Kraut) 

12. ) (Hampe) the purest he could buy 
13. $ Wagner's Jahresb., 1877 .... 


According to Rammelsberg (Kerl's Handbuch) 
the Si which is always found in aluminium is in 
part combined with it, and this combined Si 
changes by treatment with HC1 into either SiO 2 , 
which remains, or into SiH 4 , which escapes ; while 
another part of the Si is combined with the alu- 
minium just as graphite is with Fe ; and this part 
of the Si remains on treatment with acid as a black 
mass, not oxidized by ignition in the air. Two 
analyses of aluminium reduced from cryolite by 
sodium in a porcelain crucible gave 

SiO 2 

. 9.55 


Free Si . 
Si in SiH 4 

. 0.17 
. 0.74 


One sample of aluminium analyzed by Professor 
Rammelsburg contained as much as 10.46 percent. 
Si, and another sample even 13.9 per cent. The 
quantity of Fe varies from 2.9 to 7.5 per cent. 

M. Dumas has found that aluminium usually 
contains gases, about which he makes the follow- 
ing statements :* " On submitting aluminium in 
a vacuum to the action of a gradually increasing 
temperature up to the softening point of porcelain, 
and letting the mercury pump continue acting on 
the retort until it was completely exhausted, con- 
siderable quantities of gas were withdrawn. The 
liberation of the gas from the metal seems to take 

* Sci. Am. Suppl., Aug. 7, 1880. 


place suddenly towards a red-white heat. 200 
grammes of aluminium, occupying 80 c. c., gave 
89.5 c. c. of gas, measured at 17 and 755 mm. 
pressure. The gas consisted of 1.5 c. c. CO 2 and 
88 c. c. H. CO, T, and were absent," 

*The aluminium apex or cap of the Washington 
Monument cast by Colonel Frishmuth,of Philadel- 
phia, has the following composition : 

Al 97.75 

Fe . . . . . . 1.70 

Si 0.55 


Deville: The color of aluminium is a beautiful 
white with a slight blue tint, especially when it has 
been strongly worked. Being put alongside silver, 
their color is sensibly the same. However, common 
silver, and especialh 7 that alloyed with copper, has a 
yellow tinge, making the aluminium look whiter by 
comparison. Tin is still yellower than silver, so 
that aluminium possesses a color unlike any other 
useful metal. 

Fremy : Aluminium has a fine white color, just 
a little blue when compared with silver. When it 
has been worked, or when it contains Fe or Si, its 
blue tint acquires greater intensity. The commer- 
cial aluminium resembles silver. 

* Mineral Resources of the United States, 1883-84. 


Mallet: Absolutely pure aluminium is percepti- 
bly whiter than the commercial metal ; on a cut 
surface very nearly pure tin-white, without bluish 
tinge, as far as could be judged from the small 
pieces examined. 

Mierzinski : The pure white color of aluminium 
is very brilliant ; it has a tint lying between the 
color of tin and zinc, although on account of its 
usual blue shading, even in a poor light, it cannot 
be confounded with them or with any white metal. 


Deville: Aluminium like silver is able to take a 
very beautiful mat which keeps indefinitely in the 
air. It is obtained easily by plunging the surface 
for an instant in a very dilute solution of caustic 
soda, washing in a large quantity of water and at 
last dipping in strong nitric acid. Under these 
conditions, all the foreign materials which might 
contaminate it, except silicon in large proportion, 
dissolve and leave the metal quite white and with 
a very pleasing appearance. 

Mierzinski: The peculiar lustre of aluminium, 
however, is not permanent. With time, the objects 
take on their plain faces an olive green coloration, 
and look much less agreeably. Their former white 
color can be restored by Mourey's receipt, by placing 
them first in dilute hydrofluoric acid, 1000 parts 


water to 2 of acid, and then dipping them in nitric 

Bell Bros.: They recommend first washing the 
objects in benzole or essence of turpentine, before 
treating with NaOH and HNO 3 , as above. 


Deville: Aluminium may be polished and bur- 
nished easily, but it is necessary to employ as an 
intermediate material between the stone and polish- 
ing powder a mixture of stearic acid and essence of 
turpentine, finishing with pure essence of turpen- 
tine. In general, the polished surfaces are of a less 
agreeable appearance than the mat, the blue tint of 
the metal becoming more manifest. But, in this 
work, the experience and practice of the workers 
in aluminium is far from being complete ; each metal 
requires a special way of working, and we may ex- 
pect yet for a material so new that progress will be 
made in this direction. 

Bell Bros. : Aluminium is easily polished and 
burnished. Use a mixture of equal parts of rum 
and olive oil as an intermediate substance between 
the polishing stone and the powder used. The 
polishing stone is steeped in this mixture, and will 
then burnish the metal as silver and copper are bur- 
nished, care being taken not to press too heavily on 
the burnishing instrument. 

Kerl & Stohman : The use of the old means of 


polishing and burnishing metals, such as soap, wine, 
vinegar, linseed-oil, decoction of marshmallow, etc., 
is not effective with aluminium, but, on the contrary, 
is even harmful ; because, using them, the blood 
stone arid the burnishing iron tear the metal as 
fine stone does glass. Oil of turpentine has also 
been used, but with no good effect. Mourey found, 
after many attempts, that a mixture of equal weights 
of olive oil and rum, which were shaken in a bottle 
till an emulsified mass resulted, gave a very bril- 
liant polish. The polishing stone is dipped in this 
liquid, and the metal polished like silver, except 
that one must not press so hard in shining up. 
The peculiar black streaks which form under the 
polishing stone need cause no trouble ; they do not 
injure the polish in the least, and can be removed 
from time to time by wiping with a lump of cotton. 
The best way to clean a soiled surface and remove 
grease is to dip the object in benzine, and dry it in 
fine sawdust. Hammered and pressed objects of 
aluminium may, before polishing, be very easily 
ground by using olive oil and pumice. 


Deville: The odor of pure aluminium is sensibly 
nothing, but the metal strongly charged with 
silicon will exhale the odor of silicuretted hydro- 
gen, exactly represented by the odor of cast iron. 
But, even under these unfavorable circumstances, 


the smell of the metal is only appreciable to persons 
experienced in judging very slight sensations of 
this kind. 

"Watts: When pure, aluminium is quite desti- 
tute of taste or odor. 


Deville : Pure aluminium has no tast, but the 
impure and odorous metal may have a taste like 
iron, in any case only very slight. 


Deville: Aluminium may be forged or rolled 
with as much perfection as gold or silver. It is 
beaten into leaves as easily as they, and a very 
experienced gold beater, M. Rousseau, has made 
leaves as fine as those of gold or silver, which are 
put up in books. I know of no other useful 
metal able to stand this treatment. Before rolling 
a bar of aluminium it is well to prepare the metal 
by forging it on all sides, and commencing work 
with a hammer. Aluminium is tempered at a 
very low red heat ; or the plate is heated just until 
the black trace left on its surface by a drop of oil 
put there and which is carbonized has entirely dis- 

Mallet: With absolutely pure aluminium the 
malleability was undoubtedly improved, the metal 


yielding easily to the hammer, bearing distortion 
well, and flattening in two or three directions 
without cracking. It seemed to be sensibly less 
hardened by hammering than the ordinary metal 
of commerce. 

'Chemical News,' 1859: M. Degousse has suc- 
ceeded in beating aluminium into leaves as thin as 
those obtained of gold or silver. The operation is 
attended with a certain difficulty, and it is neces- 
sary to temper the metal frequently. This can- 
not be done, however, in the ordinary manner 
as with gold or silver; only a very slight heat 
must be employed. The beating is done as usual. 
These thin aluminium leaves can be substituted for 
silver leaf. They have a less brilliant color, but 
are much more durable, and may be employed 
advantageously for decorative purposes. A very 
thin leaf will burn like paper when made into a 
roll, with a brilliant white flame. 

Kerl & Stohman : Aluminium may be rolled as 
easily as other metals, but it must be annealed 
oftener. The annealing of objects made of it is 
not more difficult than that of other metals. The 
moment the metal begins to glow its annealing is 
complete. Those metal-workers who are anxious 
about the exact point of time can rub the top of 
the article to be annealed with a lump of fat, the 
disappearance of the fat shows the moment in 
which the object is to be removed from the anneal- 
ing oven. Aluminium can also be pressed or 


stamped into all forms of hollow and round vessels, 
in a stamping press. But there must be used a 
kind of varnish of 4 parts of oil of turpentine and 
1 part of stearic acid. 

Bell Bros. : Aluminium can be beaten out, hot 
or cold, to the same extent and as perfectly as gold 
and silver, and may be rolled in much the same 
way. Thin leaves may be used in the same man- 
ner as gold and silver leaf. Covered iron ingot 
moulds serve best for casting bars of the metal to 
be rolled. Aluminium quickly loses its temper, 
and therefore requires frequent reheating at a dull 
red heat ; when the plates are very thin this de- 
mands great attention. 

Mierzinski: The extensibility of aluminium is 
quite high, standing near to gold and silver. It 
may easily be beaten out or rolled without tearing. 
In beating to leaf it should at first be warmed only 
to 100 or 150, an actual glowing heat has proved 
to be very unsuitable. Such leaves are especially 
suitable for showing the characteristic qualities of 
the metal ; for instance, it dissolves with extraor- 
dinary quickness in caustic alkali, leaving the iron, 
which is always present. This leaf is also very 
combustible, even in a gas flame, burning with a 
brilliant, sparkling light ; the resulting A1 2 3 is 
melted, and as hard as corundum. While water 
does not appear to be decomposed by aluminium 
in compact masses at 100, yet it does so when in 
the extremely attenuated form of leaf. In pure, 


boiling water the leaf slowly evolves hydrogen, 
after several hours the leaves are half gone, being 
changed into hydrated alumina. Aluminium leaf 
was first made by C. Falk & Co., Vienna. 


Deville : Aluminium behaves very well at the 
drawing plate. M. Yangeois obtained in 1855, 
with a metal far from being pure, wires of extreme 
tenuity, which were used to make aluminium pas- 
sementere. However, the metal deteriorates much 
in the operation, and the threads become flexible 
again only after an annealing very delicately per- 
formed, because of the fineness of the threads and 
the fusibility of the metal. The heat of the air 
coming from the top of the chimney over an Ar- 
gand burner is sufficient to anneal them. 

Bell Bros. : Aluminium is easily drawn into 
wire. Run the metal into an open mould, so as to 
form a flat bar of about one-half inch section, the 
edges of which are beaten very regularly with a 
hammer. The diameter should be very gradually 
reduced at first, with frequent heating. When the 
threads are required very fine the heating becomes 
a very delicate operation, on account of the fine- 
ness of the threads and the fusibility of the metal. 



Deville: The elasticity of aluminium, according 
to M. Wertheirn, is sensibly the same as that of 
silver; its tenacity is also nearly the same. The 
moment after being cast it has the hardness of virgin 
silver ; when it has been worked it resembles that 
of soft iron, becomes elastic by becoming much more 
rigid, and gives the sound of steel when dropped 
on a hard body. 

Mallet: Absolutely pure aluminium was dis- 
tinctly softer than before purification. Hence its 
fracture was not easily observed, but seemed to be 
very fine grained with some appearance of fibrous 
silkiness. It seemed to be sensibly less hardened 
by hammering than the ordinary metal of com- 

Fremy : Aluminium just cast is scratched by a 
wire or edge of silver, but by hammering it be- 
comes as hard as iron and elastic. The tenacity of 
aluminium wire is between that of zinc and tin, 
but by hammering it attains that of hardened cop- 
per. When cast carefully it can be easily filed 
without fouling the tool. 

Kerl & Stohman : Aluminium resists the action 
of the engraving tool, which slides upon the sur- 
face of the metal as upon hard glass. But as soon 
as one uses the varnish of 4 parts of oil of turpen- 
tine and 1 of stearic acid, or some olive oil mixed 
with rum, the tool cuts into it like pure copper. 


Mierzinski : The tenacity of aluminium is very 
remarkable, and, according to Barlow, is 1892 kilos 
per square centimetre ; the extensibility 2.5 per cent. 

W. H. Barlow :* A ba-r of aluminium three feet 
long and one-quarter inch square was obtained, and 
different parts of it subjected to tests for tension, 
compression, and transverse strain, elasticity, elastic 
range, and ductility. It will be seen on reference 
to the results that the weight of a cubic inch was 
0.0275 pound, showing a specific gravity of 2.688, 
and its ultimate tensile strength was about twelve 
tons per square inch. The range of elasticity is 
large, the extreme to the yielding point being one- 
two hundredth of the length. The modulus of 
elasticity is 10,000. The ductility in samples two 
inches long was 2.5 per cent. Taking the tensile 
strength of the metal in relation to its weight, it 
shows a high mechanical value. These results are 
thus tabulated : 

Weight of Tensile Length of a 
1 cubic foot strength bar able to sup- 
in pounds, port its weight, 
in pounds. in feet. 

Cast Fe . . . .444 16,500 5351 

Bronze . . . .525 36,000 9893 

Wrought Fe . 480 50,000 15,000 

Steel 490 78,000 23,040 

Al 168 26,800 23,040 

It thus appears that taking the strength of alu- 
minium in relation to its weight, it possesses a 

* Rpt. Brit. A. A. S., 1882, p. 668. 


mechanical value about equal to that of steel of 
35 tons per square inch tensile strength. 

Mierzinski: Kamarsch (Dingier 172, 55) obtains 
the following results as the strength of aluminium 
wire : 


Millimetres. 1st trial. 2d trial. Mean. Kilos per sq. millimetre. 

0.225 661 653 657 12.975 

0.205 524 506 515 12.255 

0.160 307 311 309 12.700 

0.145 246 252 249 11.845 


Deville: A very curious property, which alumi- 
nium shows the more the purer it is, is its excessive 
sonorousness, so that a bar of it suspended by a 
fine wire and struck sounds like a crystal bell. 
M. Lissajous, who with me observed this property, 
has taken advantage of it to construct tuning forks 
of aluminium, which vibrate very well. I also 
tried to cast a bell, which has been sent to the 
Royal Institution at London at the request of my 
friend Rev. J. Barlow, vice-president and secretary 
of the institution. This bell, cast on a model not 
well adapted to the qualities of the metal, gives a 
sharp sound of considerable intensity, but which 
is not prolonged, as if the clapper or support hin- 
dered the sound, which, thus hindered, becomes 
far from agreeable. The sound produced by the 
ingots is, on the contrary, very pure and prolonged. 


Ill the experiments made in Mr. Faraday's labora- 
tory, this celebrated physicist has remarked that 
the sound produced by an ingot of aluminium is 
riot simple. One can distinguish, by turning the 
vibrating ingot, two sounds very near together 
and succeeding each other rapidly, according as one 
or the other face of the ingot faces the observer. 

Watts: Aluminium is highly sonorous, but a 
bell cast of it gave a sound like a cracked pot. 


Deville : The density of aluminium is 2.56 ; by 
rolling this is considerably increased, so as to become 
2.67, indicating a considerable approaching of the 
molecules to each other; which may explain the 
differences existing in its properties after being 
annealed or worked. Heated to 100 and cooled, 
it changes very little, for its specific gravity is 
still 2.65. The following table compares it with 
the other metals : 





Sp.Gr. Al.= 
8 6 








2 8 




Since the metal has been in commerce it has 
been sold at a high price ; at present (1859) it can 
be bought in large quantities at 300 fr. per kilo ; 
it is, therefore, much dearer than silver. But, 
because of the difference in their densities, for 
equal volumes of aluminium and silver, the value 
of the former must be divided by 4 in order to 
compare them; making a volume of aluminium 
much cheaper than an equal volume of silver, 
while, besides, it is much stronger. So, to-day, 
Al may be considered as costing 75 fr. to Ag 
220 fr. 

Mallet: The specific gravity of absolutely pure 
aluminium was carefully determined at 4 C., and 
the mean of three closely agreeing observations 
gave 2.583. 


Deville: Aluminium melts at a temperature 
higher than that of zinc, lower than that of silver, 
but approaching nearer to that of zinc than silver. 
It is, therefore, quite a fusible metal. 

Mallet : It seems that pure aluminium is a little 
less fusible than the commercial metal. 

Mierzinski: The melting point of aluminium 
can be taken as about 700 C. 



Deville: Aluminium is absolutely fixed, and 
loses no part of its weight when it is violently 
heated in a forge fire in a carbon crucible. 

Watts: Aluminium heated in a closed vessel 
does not exhibit the slightest tendency to volatilize. 

Fremy : Aluminium is fixed at all temperatures. 


Deville: Aluminium conducts electricity #rith 
great facility, so that it may be considered as one 
of the best conductors known, and perhaps equal 
to silver. I found by Wheatstone's Bridge that 
it conducts eight times better than iron. M. Buff* 
has arrived at results evidently different from 
mine because we have not taken the same ground 
of comparison. The difference is due, without 
doubt, to the metal which he employed containing, 
as is easily found in many specimens, a little cryo- 
lite and fusible materials, the density of which is 
near that of the metal, and which were employed 
in producing it. The complete separation of the 
metal and flux is a difficult mechanical operation, 
but which is altogether avoided by using a vola- 
tile flux. This is a condition which must be sub- 
mitted to in order to get the metal absolutely 

' Jahresb. der Chemie,' 1881, p. 94: Aluminium 


thus compares with copper and magnesium in elec- 
tric conductivity : 

At 0. At 100. 

Cu .... 45.74 33.82 

Mg .... 24.47 17.50 

Al .... 22.46 17.31 

After Al come red brass, Cd, yellow brass, Fe, 
Zn, Pb, Ag, Sb, Bi, in the order given. 

Fremy : The electric conductivity of aluminium 
is 51.5, copper being 100 ; or 33.74, silver being 


Deville: It is generally admitted that conductiv- 
ity for heat and electricity correspond exactly in 
the different metals. A very simple experiment 
made by Mr. Faraday in his laboratory seems to 
place aluminium very high among metallic con- 
ductors. He found that it conducted heat better 
than silver or copper. 

Watts: Aluminium conducts heat better than 

4 Jahresb. der Chemie,' 1881, p. 94: Aluminium 
has the following conductivity for heat: 

AtO. At 100. 

Cu .... 0.7198 0.7226 

Mg 0.3760 0.3760 

Al .... 0.3435 0.3619 

After Al come red brass, Cd, yellow brass, Fe, 
Zn, Pb, Ag, Sb, Bi in the order given. 


Mierzinski: No less remarkable than the con- 
ductivity of aluminium for electricity is that for 
heat. According to Calvert and Johnson (Dingier, 
153, 285), that of silver being 1000, aluminium is 


Deville: According to the experiments of M. 
Regnault, the specific heat of aluminium corre- 
sponds to its equivalent 13.75, from which we may 
conclude that it must be very large when compared 
with all the other useful metals. One can easily 
perceive this curious property by the considerable 
time which it takes an ingot of the metal to get 
cold. We might even suggest that a plate of alu- 
minium would make a good chafing dish. Another 
experiment makes this conclusion very evident. 
M. Paul Morin had the idea to use aluminium for 
a plate on which to cook eggs,. the sulphur of which 
attacked silver so easily ; and he obtained excellent 
results. He noticed, also, that the plate kept its 
heat a much longer time than the silver one. This 
exceptional property should be utilized for some- 

Mallet: The specific heat of absolutely pure 
aluminium was 0.2253, therefore the atomic heat 
is 0.2253 times 27.02 or 6.09. 

Fremy : The specific heat of aluminium is 


0.2181 ; larger than that of any other useful metal, 
which accords with its small atomic weight. 


Deville: I have found, as also MM. Poggen- 
dorfF and Reiss, that aluminium is very feebly 


Deville : Aluminium often presents a crystalline 
appearance when it has been cooled slowly. When 
it is not pure the little crystals which form are 
needles, and cross each other in all directions. 
When it is almost pure it still crystallizes by 
fusion, but with difficulty, and one may observe 
on the surface of the ingots hexagons which ap- 
pear regularly parallel along lines which centre in 
the middle of the polygon. It is an error to con- 
clude from this observation that the metal crystal- 
lizes in the rhombohedral system. It is evident 
that a crystal of the regular system may present a 
hexagonal section ; while, on the other hand, in 
preparing aluminium by the battery at a low tem- 
perature, I have observed complete octahedrons, 
which were impossible of measurement, it is true, 
but their angles appeared equal. 



REMARK: Unless specifically stated otherwise, 
the properties here mentioned are those of the 
pure metal and not of the commercial, the impuri- 
ties of which generally modify the properties of 
the aluminium more or less. 


Deville: Air, wet or dry, has absolutely no 
action on aluminium. No observation which has 
come to my knowledge is contrary to this assertion, 
which may easily be proved by any one. I have 
known of beams of balances, weights, plaques, 
polished leaf, reflectors, etc., of the metal exposed 
for months to moist air and sulphur vapors, and 
showing no trace of alteration. We know that 
aluminium may be melted in the air with impun- 
ity. Therefore air and also oxygen cannot sensi- 
bly affect it ; it resisted oxidation in the air at the 
highest heat I could produce in a cupel furnace, a 
heat much higher than that required for the assay 
of gold. This experiment is interesting, especially 


when the metallic button is covered with a layer 
of oxide which tarnishes it, the expansion of the 
metal causes small branches to shoot from its sur- 
face, which are very brilliant, and do not lose their 
lustre in spite of the oxidizing atmosphere. M. 
Wbhler has also observed this property on trying 
to melt the metal with a blowpipe. M. Peligot 
has profited by it to cupel aluminium. I have 
seen buttons of impure metal cupelled with lead 
and become very malleable. 

With pure aluminium the resistance of the metal 
to direct oxidation is so considerable that at the 
melting point of platinum it is hardly appreciably 
touched, and does not lose its lustre. It is well 
known that the more oxidizable metals take this 
property away from it. But silicon itself, which 
is much less oxidizable, when alloyed with it 
makes it burn with great brilliancy, because there 
is formed a silicate of aluminium. 

Watts : Aluminium may be heated intensely in 
a current of air in a muffle without undergoing 
more than superficial oxidation. When heated as 
foil with a splinter of wood in a current of oxygen 
it burns with a brilliant, bluish-white light. 

1 Chemical News,' 1859 : Wohler finds that alu- 
minium leaf burns brightly in air and in oxygen 
with a brilliant light. The A1 2 3 formed is as 
hard as corundum. Wire burns in oxygen like 
iron wire, but the combustion cannot continue be- 
cause the wire fuses. 


Mterzinski: Aluminium does not change at a 
somewhat high temperature in the air; hut if 
heated to whiteness it burns, with the production 
of strong light, to A1 2 3 , which covers the surface 
of the bath. 


Deville: "Water has no action on aluminium, 
either at ordinary temperatures, or at 100, or at 
a red heat bordering on the fusing point of the 
metal. I boiled a fine wire in water for half an 
hour and it lost not a particle in weight. The 
same wire was put in a glass-tube heated to red- 
ness by an alcohol lamp and traversed by a current 
of steam, but after several hours it had not lost its 
polish, and had the same weight. To obtain any 
sensible action it is necessary to operate at the 
highest heat of a reverberatory furnace, a white 
heat. Even then the oxidation is so feeble that it 
develops only in spots, producing almost inappre- 
ciable quantities of APO 3 . This slight alteration 
and the analogies of the metal allow us to admit 
that it decomposes water, but very feebly. If, 
however, metal produced by M. Rose's method 
was used, which is almost unavoidably contami- 
nated with slag 'composed of chlorides of alumin- 
ium and sodium, the A1 2 C1 6 , in presence of water, 
plays the part of an acid towards aluminium, dis- 
engaging hydrogen with the formation of a sub- 


chlorhydrate of alumina, whose composition is not 
known, and which is soluble in water. When the 
metal thus tarnishes in water one may be sure to 
find chlorine in the water on testing it with nitrate 
of silver. 

Mierzinski: Cold and warm water have no 
influence on aluminium even if it is heated to 

4 Chemical Xews,' 1859 : Aluminium leaf will 
slowly decompose water at 100 ; at first it takes 
a bronze color, and after boiling some hours it 
becomes translucent. 

(H 2 S and S). 

Deville: Sulphuretted hydrogen exercises no 
action on aluminium, as may be proved by leaving 
the metal in an aqueous solution of the gas. In 
these circumstances almost all the metals, and 
especially silver, blacken with great rapidity. 
Sulph-hydrate of ammonia may be evaporated on 
an aluminium leaf, leaving on the metal only a 
deposit of sulphur which the least heat drives 

Aluminium may be heated in a glass tube to a 
red heat in vapor of sulphur without altering the 
metal. This resistance is such that in melting 
together poly sulphide of potassium and some 
aluminium containing copper or iron, the latter are 


attacked without the aluminium being sensibly 
affected. Unhappily, this method of purification 
may not be employed because of the protection 
which aluminium exercises over foreign metals. 
Under the same circumstances gold and silver dis- 
solve up very rapidly. However, at a high tempera- 
ture I have observed that it combines directly with 
sulphur to give A1 2 S 3 . These properties varying 
so much with the temperature form one of the 
special characteristics of the metal and its alloys. 

Fremy : H 2 S is without action on aluminium, 
acting towards it as towards the sulphides of iron, 
zinc, or copper. It is true that aluminium decom- 
poses Ag 2 S, but it sets the sulphur at liberty and 
combines with the silver. These facts are in ac- 
cordance with the resistance the metal offers to 
free sulphur. 


Deville : Sulphuric acid, diluted in the propor- 
tion most suitable for attacking the metals which 
decompose water, has no action on aluminium ; and 
contact with a foreign metal does riot help, as with 
zinc, the solution of the metal, according to M. de 
la Rive. This singular fact tends to remove alu- 
minium considerably from, those metals. To 
establish it better, I left for several months some 
globules weighing only a few milligrammes in con- 
tact with weak H 2 S0 4 , and they showed no visible 


alteration; however the acid gave a faint precipi- 
tate with aqua ammonia. 

Fremy : H 2 S0 4 , dilute or concentrated, exercises 
in the cold only a very slight sensible action on 
aluminium, the pure metal is attacked more slowly 
than when it contains foreign metals. The presence 
of silicon gives rise to a disengagement of Sill 4 , 
which communicates to the hydrogen set free a 
tainted odor. Concentrated H 2 S0 4 dissolves it 
rapidly with the aid of heat, disengaging sulphurous 
acid gas (SO 2 ). 


Deville: Nitric acid, weak or concentrated, does 
not act on aluminium at the ordinary temperature. 
In boiling HXO 3 the solution takes place, but with 
such slowness that I had to give up this mode of dis- 
solving the metal in my analyses. By cooling the 
solution all action ceases. M. Hulot has obtained 
good results on substituting aluminium for plati- 
num in the Grove battery. 


Deville: The true solvent of aluminium is HC1, 
weak or concentrated ; but, when the metal is per- 
fectly pure, the reaction takes place so slowly that 
M. Favre, of Marseilles, had to give up this way of 
attack in determining the heat of a combination of 


the metal. But impure aluminium is dissolved 
very rapidly. At a very low temperature gaseous 
HC1 attacks the metal and changes it into A1 2 C1 6 . 
Under these circumstances iron does not seem to 
alter; able, no doubt, to resist by covering itself 
with a very thin protecting layer of FeCl 2 . This 
experiment would lead me to admit that it is the 
HC1 and not the water which is decomposed by 
aluminium; and, in fact, the metal is attacked 
more easily as the acid is more concentrated. This 
explains the difference of the action of solutions of 
HC1 and H 2 S0 4 , the latter being almost inactive. 
This reasoning applies also to tin. 

When the metal contains silicon, it disengages 
hydrogen of a more disagreeable smell than that 
given out by iron under similar circumstances. 
The reason of this is the production of that remark- 
able body recently discovered by MM. Wohler 
and Buff Sill 4 . "When the proportion of silicon is 
small, the whole is evolved as gas ; when in- 
creased a little, some remains in solution with the 
aluminium, and then it requires great care to 
separate the metal exactly, even when the solution 
is evaporated to dryness. If 3 to 5 per cent, of Si 
is present, it remains insoluble mixed with a little 
SiO 2 , as has been cleverly proven by Wohler and 
Buff by the action of hydrofluoric acid, which dis- 
solves the SiO 2 with evolution of H without attack- 
ing the Si itself. On dissolving commercial alu- 
minium there is sometimes obtained a black, 


crystalline residue, which, separated on a filter and 
dried at 200 to 300 takes fire in places; this 
residue is Si mixed with some SiO 2 . The presence 
of Si augments very much the facility with which 
Al is attacked by HC1. 

Mierzinski: If HC1 is present in a mixture of 
acids, it begins the destruction of the metal. HI, 
HBr, and HF act similarly to HC1. 


Deville : Alkaline solutions act with great energy 
on the metal, transforming it into aluminate of 
potash or soda, setting free hydrogen. However, 
it is not attacked by KOH or !N"aOH in fusion ; 
one may, in fact, drop a globule of the pure metal 
into melted caustic st>da raised almost to a red 
heat in a silver vessel, without observing the least 
disengagement of hydrogen. Silicon, on the con- 
trary, dissolves with great energy under the same 
circumstances. I have employed melted TaOH to 
clean siliceous aluminium. The piece is dipped 
into melted XaOH kept almost at red heat. At 
the moment of immersion several bubbles of H 
disengage from the metallic surface, and when they 
have disappeared, all the Si of the superficial layer 
of Al has been dissolved. It only remains to wash 
well with water and dip it into nitric acid, when 
the aluminium takes a beautiful mat. 

Mallet : The pure metal presents greater resist- 


ance to the prolonged action of alkalies than the 

Mierzinski : Lime-water acts similarly to NaOH 
or KOH, with the difference that the resulting 
calcium compound is precipitated. 


Deville: Aqua ammonia acts only feebly on 
aluminium, producing a little A1 2 3 , which, accord- 
ing to a very curious observation of Wohler, has 
the property of partly dissolving in the ammonia. 
In an atmosphere in which ammonia was present, 
the metal did not lose its lustre, which is easily 
explained, because it is only in contact with water 
that the oxidization of the metal takes place, with 
disengagement of hydrogen. 


Deville : Weak acetic acid acts oh aluminium in 
the same way as H 2 S0 4 , i. e., in an inappreciable 
degree or with extreme slowness. I used for the 
experiment acid diluted to the strength of strongest 
vinegar. M. Paul Morin left a plaque of the metal 
a long time in wine which contained tartaric acid 
in excess and acetic acid, and found the action on it 
quite inappreciable. The action of a mixture of 
acetic acid and NaCl in solution in pure water on 
pure aluminium is very different, for the acetic 


acid replaces a portion of the HC1 existing in the 
NaCl, rendering it free. However, this action is 
very slow on the Al, especially if it is pure. 

The practical results flowing from these observa- 
tions deserve to be clearly defined, because of the 
applications which may be made of aluminium to 
culinary vessels. I have observed that the tin so 
often used, and which each day is put in contact 
with ivTaCl and vinegar, is attacked much more 
rapidly than aluminium under the same circum- 
stances. Although the salts of tin are very poison- 
ous, and their action on the economy far from 
being negligible, the presence of tin in our food 
passes unperceived because of its minute quantity. 
Under the same circumstances, aluminium dissolves 
in less' quantity; the acetate of Al formed resolves 
itself on boiling into insoluble APG 3 or an insoluble 
sub-acetate, having no more taste or action on the 
body than clay itself. It is for that reason, and 
because it is known that the salts of the metal have 
no appreciable action on the body, that aluminium 
may be considered as an absolutely harmless metal. 


Deville : The action of any salt whatever may 
be easily deduced from the action of the acids on 
the metal. We may, therefore, predict that in acid 
solutions of sulphates and nitrates aluminium will 
precipitate no metal, not even silver, as Wohler has 


observed. But the hydrochloric solutions of the 
same metals will be precipitated, as MM. Tissier 
have shown. Likewise, in alkaline solutions, Ag, 
Pb, and metals high in the classification of the 
elements are precipitated. 

It may be concluded from this that' to deposit 
aluminium on other metals by means of the bat- 
tery, it is always necessary to use acid solutions in 
which IIC1, free or combined, should be absent. 
For similar reasons the alkaline solutions of the 
same metals cannot be employed, although they 
give such good results in plating common metals 
wnth gold and silver. It is because of these curious 
properties that gilding and silvering aluminium 
are so difficult. M. Paul Morin and I have often 
tried a bath of basic sulphide of gold, or hyposul- 
phite of silver, with a large excess of sulphurous 
acid, with no good results. But M. Mourey, who 
has already rendered great services in galvanoplasty, 
readily gilds and silvers aluminium for commerce 
with astonishing skill when we consider the short 
time he has had to study this question. I know 
also that M. Christofle has gilded it, but I am 
entirely ignorant of the processes employed by these 
gentlemen. The coppering of aluminium by the 
battery is effected very easily by means of M. Hulot's 
process. He uses simply a bath of acid sulphate 
of copper. The layer of copper, if well prepared, 
is very solid. 

All that I have said on the subject of the action 


of metallic salts is true only for pure aluminium. 
Impure metal, especially if it contains iron or sodium, 
acts then in producing in the copper salts with which 
I operate a deposit of metallic Cu. But this phe- 
nomenon, even in the most unfavorable cases, is 
produced very slowly, and if a leaf of aluminium 
is used one may see at the end of several weeks 
the texture of the metal etched with red fibres, as 
if the Fe and Al were only in juxtaposition, and 
the ferruginous fibres acted alone. Moreover, the 
deposit is only local, and little by little becomes 
complete ; but it is slower as the metal is purer. 

Mierziuski: Silver is precipitated by Al from a 
nitrate solution, feebly acid or neutral, in dendrites ; 
the separation begins after six hours ; from an am- 
moniacal solution of AgCl or Ag 2 Cr0 4 , Al precipi- 
tates the metal immediately as a crystalline powder. 

From CuSO 4 or Cu(N0 3 / solution, Al separates 
Cu only after two days, in dendrites or octahedra ; 
from the latter it also precipitates a basic salt as a 
green, insoluble powder; from a CuCl 2 solution the 
Cu falls immediately ; somewhat slower from solu- 
tion of acetate of copper. The sulphate or nitrate 
solution behaves similarly if a little KC1 is added 
to it, and the precipitation is complete in presence 
of excess of Al. 

From Hg 2 Cl 2 , Hg 2 Cy 2 , and Hg 2 (X0 3 ) 2 , Hg sepa- 
rates first, and then forms an amalgam with the 
Al which decomposes water at ordinary tempera- 
tures or oxidizes in the air with development of 


much heat ; the same qualities are possessed by the 
amalgam formed by warming the two metals to- 
gether in an atmosphere of CO 2 . 

From Pb(N0 3 ) 2 and Pb(C 2 H 3 2 / the metal sepa- 
rates slowly in crystals ; from PbCl 2 immediately ; 
an alkaline solution of PbCrO gives Pb and Cr 2 3 . 

From an alcoholic solution of HgCl 2 the Hg is 
precipitated much quicker with a gentle heat. Al 
also reduces Hg from a solution of Hgl 2 in KI. 
Al separates Hg from HgCl 2 vapors, and A1 2 C1 6 
deposits in the cooler part of the tube, the remain- 
ing Al being melted by the heat of the reaction. 
Al acts likewise toward melted As^Cl, the silver 

5 / 

set free being melted by the heat of the reaction. 
Zn is easily thrown down from alkaline solution. 

Fremy: Aluminium decomposes a very large 
number of metallic solutions, which takes place 
especially easily if the solution is made alkaline 
or ammoniacal. Acid, and especially neutral solu- 
tions, are less favorable for the experiment. All 
the chlorides, excepting KC1 and NaCl,are reduced 
by it. A1 2 C1 6 is no exception, for the solution is 
decomposed with evolution of hydrogen. Alu- 
minium easily resists solutions of Nad and alum 
separately, but dissolves in a mixed solution of 
these two salts. In alkaline solution, the metals 
are precipitated because of the facility with which 
aluminates of the alkalies are formed. 

Watts (2d Supplement) : The action of alumin- 
ium on metallic solutions is as follows : Cu is pre- 


cipitated from copper salts ; Pb is slowly precipi- 
tated from lead salts ; Ag is precipitated from a 
slightly acid or neutral solution of Ag^O 3 ; Zn is 
readily precipitated from zinc salts. 


Deville: Aluminium may be melted in nitre 
without undergoing the least alteration, the two 
materials rest in contact without reacting, even at 
a red heat, at which temperature the salt is plainly 
decomposed, disengaging oxygen actively. But if 
the heat is pushed to the point where nitrogen 
itself is disengaged, there the nitre becomes potassa, 
a new affinity becomes manifest, and the phenomena 
change. The metal then combines rapidly with 
the K 2 O to give aluminate of potash. The accom- 
panying phenomenon of flagration often indicates a 
very energetic reaction. Aluminium is continually 
melted with nitre at a red heat to purify it by the 
oxygen disengaged, without any fear of loss. But 
it is necessary to be very careful in doing it in an 
earthen crucible. The SiO 2 of the crucible is dis- 
solved by the nitre, the glass thus formed is decom- 
posed by the aluminium, and the silicide of alu- 
minium formed is then very oxidizable, especially 
in the presence of alkalies. The purification by 
nitre ought to be made in an iron crucible well 
oxidized by nitre inside. 

Fremy : At the melting point, aluminium is not 


attacked by nitre ; this property has been at times 
utilized to oxidize and then remove the metals 
alloyed with it, but it is now demonstrated that 
this mode of purification is very imperfect. 

Mierzinski : Heated to redness with nitre, alu- 
minium burns with a fine blue flame. 


Deville : By treating silicates and borates with 
aluminium silicon and boron may be obtained. 
The process is described at the end of Deville's 
book, but is too long and foreign to the subject in 
hand to be given here. 

Tissier : Aluminium melted in an ordinary white 
glass vessel oxidizes itself at the expense of the 
SiO 2 , setting free silicon, and the alumina formed 
combines with the alkali forming an alurninate. 
In experiments which we have made, the metal 
became covered with a thin layer of silicon, while the 
metal which remained underneath was still malle- 
able and did not appear to be combined with Si. 


Tissier: This salt is without action on the metal 
and makes its best flux, especially so because of the 
property which it has of dissolving the alumina 
with which the metal may be contaminated and 


which encrusts little globules. The fluorspar, by 
dissolving this crust, facilitates their reunion. 


Tissier : We have heated to white heat a mixture 
of pure Ca 3 (P0 4 ) 2 and aluminium leaf, without the 
metal losing its metallic appearance. This material 
thus appears to have no action on the metal. 


Deville : A solution of sodium or potassium 
chloride, in which is put a pure aluminium wire, 
seemed to me to exercise no sensible action on the 
metal, either cold or warm. It is not the same 
with the other metallic chlorides, and we may 
state that, as a general rule, these are decomposed 
by aluminium with greater facility as the metal 
which they contain belongs to a higher order. The 
chlorhydrate of A\ itself dissolves aluminium 
forming a sub-chlorhydrate with evolution of hy- 

Tissier: KaCl is employed as a flux for Al in 
remelting it. It does not possess the property, like 
CaF 2 , of dissolving the A1 2 3 , and has the incon- 
venience of producing with the clay of the crucible 
a sensible quantity of A1 2 C1 6 , which may on con- 
tact with the air act in promoting the loss of a 
certain quantity of metal. 




Tissier : We made our experiments in this way : 
The Al leaf was mixed carefully with the oxide 
on which we experimented, then the mixture was 
placed in a small porcelain capsule and heated in a 
small earthen crucible which served as a muffle. 
Our results were as follows : 

MnO 2 Aluminium has no action on manganese 



Fe 2 3 By heating to white heat 1 equivalent of 
Fe 2 3 and 3 of Al, the reaction took place with 
detonation, and by heating sufficiently we obtained 
a metallic button, well melted, and containing 69.3 
per cent. Fe and 30.7 per cent. Al, being as hard 
and brittle as cast-iron. Its composition is nearly 
AlFe. It would thus appear that the decomposition 
of Fe 2 3 will not pas's the limit where the quantity 
of iron reduced is sufficient to form with the alu- 
minium the alloy AlFe. 

ZnO: A mixture of aluminium leaf and zinc 
oxide heated to whiteness did not appear to present 
the least indication of decomposition. 

PbO: We mixed 2 equivalents of litharge with 1 
of aluminium, and heated the mixture slowly up to 
white heat, when the Al reacted on the PbO with 
such intensity as to produce a strong detonation. 
We made an experiment w r ith 50 grammes of PbO 
and 2.9 grammes of Al leaf, when the crucible was 


broken to pieces and the doors of the furnace blown 

CuO : 3 grammes of black oxide of copper mixed 
with 1.03 grammes of aluminium detonated pro- 
ducing a strong explosion when the heat reached 

Mierzinski: Aluminium reduces CuO and PbO 
with explosion, Fe 2 3 only in part, forming the 
alloy AlFe. ZnO and MnO are not reduced by 

Beketoff :* He reduced baryta (BaO) with metal- 
lic aluminium in excess, and obtained alloys of 
aluminium and barium containing in one case 24 
per cent, in another 33 per cent, of Ba. 


Deville: Among the animal matters produced 
by the organism, some are acid, as sweat. These 
appear to have no sensible action on aluminium. 
Alkaline materials, as the saliva, have a greater 
tendency to oxidize it, but the whole effect produced 
is insignificant. M. Charriere has made for a patient 
on whom he practised tracheotomy a small tube 
of the metal, which remained almost unaltered 
although in contact with purulent matter. After 
a long time a little alumina was formed on it, 
hardly enough to be visible. 

* Bull, de la Soc. Chem., 1857, p. 22. 



Tissier: Only 2.65 grammes of aluminium intro- 
duced into melted red hot sodium sulphate (Na 2 S0 4 ) 
decomposed that salt with such intensity that the 
crucible was broken into a thousand pieces, and 
the door of the furnace blown to a distance. 
Heated to redness with alkaline carbonate, the 
Al w T as slowly oxidized at the expense of the CO 2 , 
C was set free, and an aluminate formed. The 
reaction takes place without deflagration. 

Mierzinski : Heated to redness with potassium 
or sodium sulphate, aluminium gives a strong 
detonation. Potassium carbonate quickly destroys 
the metal with separation of carbon. Hydrogen, 
nitrogen, sulphur, and carbon are without any 
influence on aluminium, but chlorine, iodine, bro- 
mine, and fluorine attack it rapidly. 


Deville: Aluminium, at a low temperature, con- 
ducts itself as a metal which can give a very weak 
base ; in consequence, its resistance to acids, IIC1 
excepted, is very great. It conducts itself with 
the alkalies as a metal capable of giving a quite 
energetic acid, it being attacked by K 2 and Na 2 

O O v 

dissolved in water. But, this affinity is still 
insufficient to determine the decomposition of 


melted KOH. For a stronger reason it does not 
decompose metallic oxides at a red heat. This is 
why, in the muffle, the alloy of aluminium and 
copper gives black CuO, and this also accounts for 
the alloy of aluminium and lead being capable of 
being cupelled. But, by a strange exception, and 
which does not appertain solely, I believe, to alu- 
minium, as soon as the heat is above redness the 
affinities are quickly inverted, and the metal takes 
all the properties of silicon, decomposing the oxides 
of lead and copper with the production of alumin- 

From all the experiments which have been re- 
ported and from all the observations which have 
been made, we can conclude that aluminium is a 
metal which has complete analogies with no one ot 
the simple bodies which we consider metals. In 
1855 I proposed to place it along side of chromium 
and iron, leaving zinc out of the group with which 
aluminium had been until then classed. Zinc is 
placed very well beside magnesium, there being 
intimate analogies between these two volatile 
metals. There may be found at the end of a memoir 
which M. AVohler and I published in the ' Compt 
Rendue' and the ' Ami. de Chem. et de Phys.' the 
reasons why we are tempted to place aluminium 
near to silicon and boron in the carbon series, on 
grounds analogous to those on which antimony and 
arsenic are placed in the nitrogen series. 



As has been remarked in the historical section, 
Davy was the first to try to isolate aluminium. 
His attempts were unsuccessful. The next chemist 
to publish an account of attempts in this direction 
was Oerstedt, who published a paper in 1824 in a 
Swedish periodical.* Oerstedt's original paper is 
thus translated into Berzelius' ' Jahresbericht :'f 

" Oerstedt mixes calcined and pure alumina, quite 
freshly prepared, with powdered charcoal, puts it 
in a porcelain retort, ignites and leads Cl gas 
through. The coal then reduces the alumina, and 
there results A1 2 C1 6 and CO, and perhaps also some 
phosgene, COC1 2 ; the A1 2 C1 6 is caught in the con- 
denser and the gases escape. The A1 2 C1 6 is white, 
crystalline, melts about the temperature of boiling 
water, easily attracts moisture, and evolves heat 
when in contact with water. If it is mixed with 
a concentrated potassium amalgam and heated 
quickly, it is transformed ; there results KC1, and 

* Oversigt over clct K. Danske Videnskabemes Sclkabs 
Forhandlingar og dets Medlemmers Arbeider. May, 1824, to 
May, 1825, p. 15. 

t Berz. Jahresb. der Chemie, 1827, vi. 118. 


the aluminium unites with the mercury. The new 
amalgam oxidizes in the air very quickly, and 
gives as residue when distilled in a vacuum a lump 
of metal resembling tin in color and lustre. In 
addition, Oerstedt found many remarkable prop- 
erties of the metal and of the amalgam, but he 
holds them for a future communication after further 

I have not been able to find any other paper by 
Oerstedt, but the next advance in the science is by 
Wohler, and all agree in naming him as the true 
discoverer of the metal. The following is taken 
from Poggendorf.* 

Wohler reviews the article which we have just 
given, and then continues as follows: 

" I have repeated this experiment of Oerstedt, 
but achieved no very satisfactory result. By heat- 
ing potassium amalgam with APC1 6 and distilling 
the product, there remained behind a gray melted 
mass of metal, but which, by raising the heat to 
redness, went off as green vapor and distilled as 
pure potassium. I have therefore looked around 
for another method or way of conducting the ope- 
ration, but, unpleasant as it is to say it, the reduc- 
tion of the aluminium fails each time. Since, how- 
ever, Herr Oerstedt remarks at the end of his paper 
that he did not regard his investigations in alu- 
minium as yet ended, and already several years 

* Pogg. Ann., 1827, ii. 147. 


have passed since then, it looks as if I had taken 
up one of those researches begun auspiciously by 
another (but not finished by him) because it prom- 
ised new and splendid results. I must remark, how- 
ever, that Herr Oerstedt has indirectly by his silence 
encouraged me to try to attain to further results my- 
self. Before I give the art how one can quite 
easily reduce the metal, I will say a few words 
about APCl 6 and its production. 

" I based the method of reducing aluminium on 
the reaction of A1 2 C1 6 on potassium, and on the 
property of the metal not to oxidize in water. I 
warmed in a glass retort a small piece of APCl 6 
with some potassium, and the retort was shattered 
with a strong explosion. I tried then to do it in a 
small platinum crucible, in which it succeeded very 
well. The reaction is always so violent that the 
cover must be weighted down, or it will be blown 
off'; and at the moment of reduction, although the 
crucible be only feebly heated from outside, it sud- 
denly glows inside, and the platinum is almost torn 
by the sudden shocks. In order to avoid any 
mixture of platinum with the reduced aluminium, 
I next made the reduction in a porcelain crucible 
and succeeded then in the following manner : Pat 
in the bottom of the crucible a piece of potassium 
free from carbon and oil, and cover this with an 
equal volume of pieces of APCl 6 . Cover, and heat 
over a spirit lamp, at first gently, that the crucible 
be not broken by the production of heat inside, 


and then heat stronger, at last to redness. 
and when fully cold put it into a glass of cold water. 
A gray powder separates out which on nearer ob- 
servation, especially in sunlight, is seen to consist 
of little flakes of metal. After it has separated, 
pour off the solution, filter, wash with cold water, 
and dry ; this is the aluminium." 

In reality this powder possessed no metallic 
properties, and, moreover, it contained potassium 
and APC1 6 , which gave to it the property of de- 
composing water at 100. To avoid the loss of 
A1 2 C1 6 by volatilization at the high heat developed 
during the reaction, Liebig afterwards made the 
vapor of APC1 6 pass slowly over some potassium 
placed in a long glass tube. This device of Liebig 
is nearly the arrangement which Wohler adopted 
later, in 1845, and which gave him much better 
results. The following is W6hler's second paper, 
published in 1845 : * 

" On account of the violent incandescence with 
which the reduction of A PCI 6 by potassium is ac- 
companied, this operation requires great precau- 
tions, and can be carried out only on a small scale. 
I took for the operation a platinum tube, in which 
I placed A1 2 C1 6 and near it some potassium in a 
platinum boat. I heated the tube gently at first, 
then to redness. But th reduction may also be 
done by putting potassium in a small crucible 

* Liebig's Annalen, 53, 422. 


which is placed inside a larger one, and the space 
between the two filled with APC1 6 . A close cover 
is put over the whole and it is heated. Equal 
volumes of potassium and A1 2 C1 6 are the best pro- 
portions to employ. After cooling, the tube or 
crucible is put in a vessel of water. The metal is 
obtained as a gray, metallic powder, but on closer 
observation one can see even with the naked eye 
small tin-white globules some as large as pins' heads. 
Under a microscope magnifying two hundred diam- 
eters the whole powder resolves itself into small 
globules, several of which may sometimes be seen 
sticking together, showing that the metal was 
melted at the moment of reduction. A beaten-out 
globule may be again melted to a sphere in a bead 
of borax or salt of phosphorus, but rapidly oxidizes 
during the operation, and if the heat is continued, 
disappears entirely, seeming either to reduce boron 
in the borax bead or phosphorus or P 2 5 in the salt 
of phosphorus bead. I did not succeed in melting 
together the pulverulent aluminium in a crucible 
with borax, at a temperature which would have 
melted cast iron, for the metal disappeared entirely 
and the borax became a black slag. It seems prob- 
able that aluminium, being lighter than molten 
borax, swims on it and burns. The white metallic 
globules had the color and lustre of tin. It is per- 
fectly malleable and can be hammered out to the 
thinnest leaves. Its specific gravity, determined 
with two globules weighing 32 milligrammes, was 


2.50, and with three hammered-out globules weigh- 
ing 34 milligrammes, 2.67. Ou account of their 
lightness these figures can only be approximate. 
It is not magnetic, remain's white in the air, de- 
composes water at 100, not at usual temperatures, 
and dissolves completely in caustic potash (KOH). 
When heated in oxygen almost to melting, it is 
only superficially oxidized, but it burns like zinc 
in a blast-lamp flame." 

These results of Wbhler's, especially the deter- 
mination of sp. gr., were singularly accurate when 
we consider that he established them working with 
microscopic bits of the metal. It was just such 
work that established Wohler's fame as an investi- 
gator. However, we notice that his metal differed 
from aluminium as we know it in several important 
respects, in speaking of which Deville says: "All 
this time the metal obtained by Wohler was far 
from being pure; it was very difficultly fusible, 
owing without doubt to the fact that it contained 
platinum taken from the vessel in which it had 
been prepared. It is well known that these two 
metals combine very easily at a gentle heat. More- 
over, it decomposed water at 100, which must be 
attributed either to the presence of some potassium 
or to APC1 6 , with which the metal might have 
been impregnated ; for aluminium in presence of 
APCl 6 in effect decomposes water with evolution of 

After AYohler's paper in 1845, the next improve- 


ment is that introduced by Deville, in 1854-55, 
and this is really the date at which aluminium, the 
metal, became known and its true properties estab- 
lished. He first read to the Academy an account of 
his laboratory process, by which he obtained a 
pencil of the metal. The following is his account:* 
"The following is the best method for obtaining 
aluminium chemically pure in the laboratory. 
Take a large glass tube about four centimetres in 
diameter, and put into it pure APC1 6 free from 
iron, and isolate it between two stoppers of ami- 
anthus (tine, silky asbestos). Hydrogen, well dried 
and free from air, is brought in at one end of the 
tube. The APC1 6 is heated in this current of gas 
by some lumps of charcoal, in order to drive off 
hydrochloric acid or sulphides of chlorine or of 
silicon, with which it is always impregnated. Then 
there are introduced into the tube porcelain boats, 
as large as possible, each containing several grammes 
of sodium, which was previously rubbed quite dry 
between leaves of filter paper. The tube being full 
of hydrogen the sodium is melted, the A1 2 C1 6 is 
heated and distils, and decomposes in contact with 
the sodium with incandescence, the intensity of 
which can be moderated at pleasure. The operation 
is ended when all the sodium has disappeared, and 
when the sodium chloride formed has absorbed so 
much A1 2 C1 6 as to be saturated with it. The Al 

* Ann. de. Pays, et de Chem., xliii. 24. 


which has been formed is held in the douhle 
chloride of sodium and aluminium, Al 2 Cl 6 .2!N"aCl, 
a compound very fusihle and very volatile. The 
boats are then taken from the glass tube, and their 
entire contents put in boats made of retort carbon, 
which have been previously heated in dry chlorine 
in order to remove all silicious and ferruginous 
matter. These are then introduced into a large 
porcelain tube, furnished with a prolongation and 
traversed by a current of hydrogen, dry and free 
from air. This tube being then heated to redness, 
the Al 2 Cl 6 .2XaCl distils without decomposition 
and condenses in the prolongation. There is found 
in the boats, after the operation, all the Al which 
had been reduced, collected in at most one or two 
small buttons. The boats when taken from the 
tube should be nearly free from Al 2 Cl 6 .2]N"aCl and 
also from ^aCl. The buttons of aluminium are 
united in a small earthen crucible which is heated 
as gently as possible, just sufficient to melt the 
metal. The latter is pressed together and skimmed 
clean by a small rod or tube of clay. The metal 
thus collected may be very suitably cast in an 
ingot mould." 

The later precautions added to the above given 
process were principally directed towards avoiding 
the attacking of the crucible, which always takes 
place when the metal is melted with a flux, and the 
aluminium thereby made more or less siliceous. 
The next improvement was the introduction by 



Deville of an application 
on a large scale of the lab- 
oratory method just de- 
scribed. He first put it 
up at the chemical works 
of M. du Sussex, at Javel, 
and later at the works of 
MM. Rousseau Bros., at 
Glaciere. It has at pre- 
sent only an historic inter- 
est, as it was soon modi- 
fied in its details so as to 
be almost entirely chang- 
ed, but I give it here so 
as to show the different 
phases through which the 
industry has passed. The 
text is not given in full as 
Deville describes it, which 
would be unnecessary ; but 
the condensed account 
gives a clear idea of the 
process. The full descrip- 
tion may be found in De- 
ville 'shook, or in the 'Ann. 
de Chem. et de Phys.' [3] 
xlvi. 445, where it first 

The crude APC1 6 , placed 
in the cylinder A, is vap- 


orized by the fire and passes through the tube to 
the cylinder B containing 60 to 80 kilos of iron 
nails heated to a dull-red heat. The iron retains 
as relatively fixed ferrous chloride, the ferric 
chloride and hydrochloric acid which contaminate 
the APC1 6 , and likewise transforms any sulphur 
dichloride (SCI 2 ) in it into ferrous chloride and sul- 
phide of iron. The vapors on passing out of B 
through the tube, which is kept at about 300, 
deposit spangles of ferrous chloride, which is with- 
out sensible tension at that temperature. The 
vapors then enter D, a cast-iron cylinder in which 
are three cast-iron boats each containing 300 grms. 
of sodium. It is sufficient to heat this cylinder 
barely to a dull-red heat in its lower part, for the 
reaction once commenced disengages enough heat 
to complete itself, and it is often necessary to take 
away all the fire from it. There is at first pro- 
duced in the first boat some aluminium and some 
sodium chloride, which latter combines with the 
excess of .A1 2 C1' to form the volatile chloride 
Al 2 Cl 6 .2NaCl. These vapors of double chloride 
condense on the second boat and are decomposed 
by the sodium to aluminium and sodium chloride. 
A similar reaction takes place in the third boat 
when all the sodium of the second has disappeared. 
When on raising the cover it is seen that the reac- 
tions are over, the boats are taken out, immedi- 
ately replaced by others, and are allowed to cool 
covered by empty boats. In this first operation 


the reaction is rarely complete, for the sodium is 
protected by the layer of NaCl formed at its 
expense. To make this disappear, the contents of 
the hoats are put into cast iron pots or earthen 
crucibles, which are heated until the APC1 6 begins 
to volatilize. Then the pots or crucibles are cooled 
and there is taken from the upper part of their 
contents a layer of ISTaCl, almost pure, while under- 
neath are found globules of aluminium, which are 
separated from the residue by washing with water. 
Unfortunately, the water in dissolving the A1 2 C1 6 
of the flux exercises on the metal a very rapid 
destructive action, and only the globules larger 
than the head of a pin are saved from this washing. 
These are gathered together, dried, melted in an 
earthen crucible, and pressed together with a clay 
rod. The button is then cast in an ingot mould. 
It is important in this operation to employ only well 
purified sodium, and not to melt the aluminium if it 
still contains any sodium, for in this case the metal 
takes fire and burns as long as any of the alkaline 
metal remains in it. In such a case it is necessary to 
remelt in presence of a little Al 2 Cl 6 .2JS T aCl." 

Deville says later, "Such was the detestable pro- 
cess by means of which we made the ingots of 
aluminium which were sent to the Exposition." 

Deville, after this, tried some experiments in 
which he used sodium vapor, and he thus reports 
his results in his book: "This process, which I 
have not perfected, is very easy to operate, and gave 


me very pure metal at the first attempt. I operate 
as follows : I fill a mercury bottle with a mixture 
of chalk, carbon, and carbonate of soda, in the 
proportions best for generating sodium. An iron 
tube about ten centimetres long is screwed to the 
bottle, and the whole placed in a wind furnace, 
so that the bottle is heated to red-white and the 
tube is red to its end. The end of the tube is 
then introduced into a hole made in a large earthen 
crucible about one-fourth way from the bottom, 
so that the end of the tube just reaches the inside 
surface of the crucible. The carbonic oxide (CO) 
disengaged burns in the bottom of the crucible, 
heating and drying it; afterwards the sodium flame 
appears, and then pieces of A1 2 C1 6 are thrown into 
the crucible from time to time. The salt volatilizes 
and decomposes before this sort of tuyere from 
which issues the reducing vapor. APC1 6 is added 
when the vapors coming from the crucible cease to 
be acid, and when the flame of sodium burning in 
the atmosphere of A1 2 C1 6 loses its brightness. AV hen 
the operation is finished, the crucible is broken and 
there is taken from the walls below the entrance 
of the tube a saline mass composed of N"aCl, a 
considerable quantity of globules of aluminium, 
and some sodium carbonate, which latter is in 
larger quantity the slower the operation w r as per- 
formed. The globules are detached by plunging the 
saline mass into water, when it becomes necessary 
to notice the reaction of the water on litmus. If the 



water becomes acid, it is renewed often ; if alkaline., 
the mass impregnated with metal must be digested 
in nitric acid diluted with three or four volumes of 
water, and so the metal is left intact. The globules 
are reunited by melting with the precautions before 

Deville modified these methods in various ways. 
APC1 6 is a deliquescent salt, difficult of preservation, 
and so was soon replaced by Al 2 Cl 6 .2NaCl, which 
does not present these inconveniences. The double 
chloride, however, does draw some moisture and 
holds it energetically, from which it results that at 
a high temperature it will give rise to some alumina, 
which encloses the globules of metal with a thin 
coating and so hinders their easy reunion into a 
button. Deville remarked that the presence of 
fluorides facilitated the reunion of these globules, 
which he attributed to their dissolving the coat of 
A1 2 3 on them. Since then, the employment of a 
fluoride as a flux is considered necessary to over- 
come the effect produced primarily by the APC1 6 .- 
2NaCl holding moisture so energetically. The first 
fluoride employed by Deville was fluorspar, which 
was soon replaced by cryolite. This opens up the 
subject of the reduction of aluminium from cryolite, 
and since Percy and Rose both preceded Deville in 
using it, I will first give their investigations, follow- 
ing with those which Deville published in 1859. 



We will here give H. Rose's entire paper, as an 
account of this eminent chemist's investigations 
written out by himself with great detail, describ- 
ing failures as well as successes, cannot but be of 
value to all interested in the production of alu- 

u Since the discovery of aluminium by Wohler, 
Deville has recently devised the means of procuring 
the metal in large, solid masses, in which condition 
it exhibits properties with which we were previ- 
ously unacquainted in its more pulverulent form 
as procured by Wohler's method. While, for in- 
stance, in the latter state it burns vividly to white 
earthy alumina on being ignited, the fused globules 
may be heated to redness without perceptibly oxi- 
dizing. These differences may be ascribed to the 
greater amount of division on the one hand and of 
density on the other. According to Deville, how- 
ever, Wohler 's metal contains platinum, by which 
he explains its difficulty of fusion, although it 
affords white alumina by combustion. Upon the 
publication of Deville's researches I also tried 
to produce aluminium by the decomposition of 
Al 2 Cl 6 .2XaCl by means of sodium. I did not, 
however, obtain satisfactory" results. Moreover, 
Prof. Rammelsberg, who followed exactly the 

* Pogg. Annalen, Sept. 1855. 


method of Deville, obtained but a very small pro- 
duct, and found it very difficult to prevent the 
cracking of the glass-tube in which the experiment 
was conducted by the action of the vapor of sodium 
on A1 2 C1 6 . It appeared to me that a great amount 
of time, trouble, and expense, as well as long prac- 
tice, was necessary to obtain even small quantities 
of this remarkable metal. 

" The employment of A1 2 C1 6 and its compounds 
with alkali chlorides is particularly inconvenient, 
owing to their volatility, deliquescence, and to the 
necessity of preventing all access of air during 
their treatment with sodium. It very soon occurred 
to me that it would be better to use the fluoride of 
aluminium instead of the chloride ; or rather the 
combination of the fluoride with alkaline fluorides, 
such as we know them through the investigations 
of Berzelius, who pointed out the strong affinity 
of A1 2 F 6 for NaF and KF, and that the mineral 
occurring in nature under the name of Cryolite 
was a pure compound of A1 2 F 6 and ]S"aF. 

" This compound is as well fitted for the prepara- 
tion of aluminium by means of sodium as A1 2 C1 6 
or Al 2 Cl 6 .2NaCl. Moreover, as cryolite is not vola- 
tile, is readily reduced to the most minute state of 
division, is free from water and does not attract 
moisture from the air, it affords peculiar advan- 
tages over the above-mentioned compounds. In 
fact, I succeeded with much less trouble in prepar- 
ing aluminium by exposing cryolite together with 


sodium to a strong red heat in an iron crucible, 
than by using A1 2 C1 6 and its compounds. But the 
scarcity of cryolite prevented my pursuing the ex- 
periments. In consequence of receiving, however, 
from Prof. Krantz, of Bonn, a considerable quan- 
tity of the purest cryolite at a very moderate price 
(S2 per kilo), I was enabled to renew the investi- 

" I was particularly stimulated by finding, most 
unexpectedly, that cryolite was to be obtained here 
in Berlin commercially at an inconceivably low 
price. Prof. Krantz had already informed me that 
cryolite occurred in commerce in bulk, but could 
not learn where. Shortly after, M. Rudel, the 
manager of the chemical works of H. Kunheim, 
gave me a sample of a coarse white powder, large 
quantities of which were brought from Greenland, 
by way of Copenhagen, to Stettin, under the name 
of mineral soda, and at the price of $3 per centner. 
Samples had been sent to the soap boilers, and a 
soda-lye had been extracted from it by means of 
quicklime, especially adapted to the preparation of 
many kinds of soap, probably from its containing 
alumina. It is a fact, that powdered cryolite is 
completely decomposed by quicklime and water. 
The fluoride of lime formed contains no alumina, 
which is all dissolved by the caustic soda solution; 
and this, on its side, is free from fluorine, or only 
contains a minute trace. I found this powder to 
be of equal purity to that received from Prof. 


Krantz. It dissolved without residue in HC1 (in 
platinum vessels); the solution evaporated to dry- 
ness with H 2 S0 4 , and heated till excess of acid was 
dissipated, gave a residue which dissolved com- 
pletely in water, with the aid of a little HC1. 
From this solution, ammonia precipitated a con- 
siderable quantity of alumina. The sol ution filtered 
from the precipitate furnished, on evaporation, a 
residue of sulphate of soda, free from potash. 
Moreover, the powder gave the well-known re- 
actions of fluorine in a marked degree. This 
powder was cryolite of great purity: therefore the 
coarse powder I first obtained was not the form 
in which it was originally produced. It is now 
obtainable in Berlin in great masses ; for the prepa- 
ration of aluminium it must, however, be reduced 
to a very fine powder. 

" In my experiments on the preparation of alu- 
minium, which were performed in company with 
M. Weber, and with his most zealous assistance, I 
made use of small iron crucibles, If inches high 
and If inches upper diameter, which I had cast 
here. In these I placed the finely divided cryolite 
between thin layers of sodium, pressed it down 
tight, covered with a good layer of potassium 
chloride (KC1), and closed the crucible with a well- 
fitting porcelain cover. I found KC1 the most 
advantageous flux to employ; it has the lowest 
specific gravity of any which could be used, an 
important point when the slight density of the 


metal is taken into consideration. It also increases 
the fusibility of the sodium fluoride. I usually 
employed equal weights of cryolite and KC1, and 
for every five parts of cryolite two parts of sodium. 
The most fitting quantity for the crucible was 
found to be ten grammes of powdered cryolite. 
The whole was raised to a strong red heat by 
means of a gas-air blowpipe. It was found most 
advantageous to maintain the heat for about half 
an hour, and not longer, the crucible being kept 
closely covered the whole time ; the contents were 
then found to be well fused. When quite cold the 
melted mass is removed from the crucible by means 
of a spatula, this is facilitated by striking the 
outside with a hammer. The crucible may be 
employed several times, at last it is broken by the 
hammer blows. The melted mass is treated with 
water, when, at times only, a very minute evolu- 
tion of hydrogen gas is observed, which has the 
same unpleasant odor as the gas evolved during 
solution of iron in HC1. The carbon contained in 
this gas is derived from a very slight trace of 
naphtha adhering to the sodium after drying it. 
On account of the difficult solubility of IS T aF, the 
mass is very slowly acted on by water, although 
the insolubility is somewhat diminished by the 
presence of the KC1. After twelve hours the mass 
is softened so far that it may be removed from the 
liquid and broken down in a porcelain mortar. 
Large globules of aluminium are then discovered, 


weighing from 0.8 to 0.4 or even 0.5 gramme, 
which may be separated out. The smaller globules 
cannot well be separated from the undecomposed 
cryolite and the alumina always produced by 
washing, owing to their being specifically lighter 
than the latter. The whole is treated with UNO 3 
in the cold. The APO 3 is not dissolved thereby, 
but the little globules then first assume their true 
metallic lustre. They are dried and rubbed on fine 
silk muslin ; the finely-powdered, undecomposed 
cryolite and A1 2 3 pass through, while the globules 
remain on the gauze. The mass should be treated 
in a platinum or silver vessel, a porcelain vessel 
would be powerfully acted on by the NaF. The 
solution, after standing till clear, may be evapo- 
rated to dryness in a platinum capsule, in order to 
obtain the !NaF, mixed, however, with much KC1. 
The small globules may be united by fusion in a 
small, well-covered, porcelain crucible, under a 
layer of KC1. They cannot be united without a 
flux. They cannot be united by mere fusion, like 
globules of silver, for instance, for, though they do 
not appear to oxidize on ignition in the air, yet 
they become coated w r ith a scarcely perceptible film 
of oxide, which prevents their running together 
into a mass. This fusion with KC1 is always at- 
tended with loss of aluminium. Buttons weighing 
0.85 grm. lost, when so treated, 0.05 grm. The 
KC1 when dissolved in water left a small quantity 
of A1 2 3 undissolved, but the solution contained 


none. Another portion of the metal had un- 
doubtedly decomposed the KC1 ; and a portion of 
the A1 2 C1 6 and KC1 must have been volatilized 
during fusion (other metals, as copper and silver, 
behave in a similar manner Pogg. Ixviii. 287). 
I therefore followed the instructions of Deville, 
and melted the globules under a stratum of 
Al 2 Cl 6 .2NaCl in a covered porcelain crucible. The 
salt was melted first, and then the globules of 
metal added to the melted mass. There is no loss, 
or a very trifling one of a few milligrammes of 
metal, by this proceeding. "When the aluminium 
is fused under KC1 its surface is not perfectly 
smooth, but exhibits minute concavities; with 
Al 2 Cl 6 .2XaCl this is not the case. The readiest 
method of preparing the Al 2 Cl 6 .2]S T aCl for this pur- 
pose is by placing a mixture of alumina and carbon 
in a glass tube, as wide as possible, and inside this a 
tube of less diameter, open at both ends, and contain- 
ing XaCl. If the spot where the mixture is placed 
be very strongly heated, and that where the NaCl 
is situated, more moderately, while a current of 
chlorine is passed through the tube, the vapor of 
A1 2 C1* is so eagerly absorbed by the !N"aCl that no 
A1 2 C1 6 , or, at most, a trace, is deposited in any other 
part of the tube. If the smaller tube be weighed 
before the operation, the amount absorbed is readily 
determined. It is not uniformly combined with 
the EaCl, for that part which is nearest to the 



mixture of charcoal and alumina will be found to 
have absorbed the most. 

" I have varied in many ways the process for the 
preparation of aluminium, but in the end have 
returned to the one just described. I often placed 
the sodium in the bottom of the crucible, the pow- 
dered cryolite about it, and the KC1 above all. On 
proceeding in this manner, it was observed that 
much sodium was volatilized, burning with a strong, 
yellow flame, which never occurred when it was cut 
into thin slices and placed in alternate layers with 
the cryolite, in which case the process goes on quietly. 
When the crucible begins to get red hot, the tempera- 
ture suddenly rises, owing to the commencement of 
the decomposition of the compound ; no lowering 
of the temperature should be allowed, but the 
heat should be steadily maintained, not longer, 
however, than half an hour. By prolonging the 
process a loss would be sustained, owing to the 
action of the KC1 on the aluminium. Nor does 
the size of the globules increase on extending the 
time even to two hours; this effect can only be 
produced by obtaining the highest possible tempera- 
ture. If the process be stopped, however, after five 
or ten minutes of very strong heat, the production 
is very small, as the metal has not had sufficient 
time to conglomerate into globules, but is in a pul- 
verulent form and burns to APO 3 during the cooling 
of the crucible. No advantage is gained by mixing 
the cryolite with a portion of chloride before plac- 


ing it between the layers of sodium, neither did I 
increase the production by using Al 2 Cl 6 .2NaCl to 
cover the mixture instead of KC1. I repeatedly 
employed Nad, decrepitated, as a flux in the 
absence of KC1, without remarking any important 
difference in the amount of metal produced, although 
a higher temperature is in this case required. The 
operations may also be conducted in refractory 
unglazed crucibles made of stoneware, and of the 
same dimensions, although they do not resist so 
well the action of the sodium fluoride at any high 
heats, but fuse in one or more places. The iron 
crucibles fuse, however, when exposed to a very 
high temperature in a charcoal fire. The product 
of metal was found to vary very much, even when 
operating exactly in the manner recommended and 
with the same quantities of materials. I never 
succeeded in reducing the whole amount of metal 
contained in the cryolite (which contains only 13 
per cent. Al). By operating on 10 grammes of 
cryolite, the quantity I always employed in the 
small Fe crucible, the most successful result was 
0.8 grm. But 0.6 or even 0.4 grm. may be con- 
sidered favorable ; many times I obtained only 0.3 
grm., or even less. These very different results 
depend on various causes, more particularly, how- 
ever, on the degree of heat obtained. The greater 
the heat the greater the amount of large globules, 
and the less amount of minutely divided metal to 
oxidize during the cooling of the crucible. I sue- 


ceeded once or twice in reducing nearly the whole 
of the metal to one single button, weighing 0.5 
grm., at a very high heat in a stoneware crucible. 
I could not always obtain the same heat with the 
blowpipe, as it depended in some degree on the 
pressure in the gasometer in the gasworks, which 
varies at different hours of the day. The follow- 
ing experiment will show how great the loss of 
metal may be owing to oxidation during the 
slow cooling of the crucible and its contents : In a 
large iron crucible were placed 35 grms. of cryolite 
in alternate layers with 14 grms. of sodium and 
the whole covered with a thick stratum of KC1. 
The crucible, covered by a porcelain cover, was 
placed in a larger earthen one, also covered, and 
the whole exposed to a good heat in a draft furnace 
for one hour and cooled as slowly as possible. The 
product in this case was remarkably small, for 
0.135 grm. of aluminium was all that could be 
obtained in globules. The differences in the amounts 
reduced depend also in some degree on the more or 
less successful stratification of the sodium with the 
powered cryolite, as much of the latter sometimes 
escapes decomposition. The greater the amount of 
sodium employed, the less likely is this to be the 
case ; however, owing to the great difference in their 
prices, I never emploj^ed more than 4 grms. of 
sodium to 10 grms. of cryolite. In order to avoid 
this loss by oxidation I tried another method of 
preparation : Twenty grms. of cryolite were heated 


intensely in a gun-barrel in a current of hydrogen, 
and then the vapor of 8 grms. of sodium passed 
over it. This was effected simply by placing the 
sodium in a little iron tray in a part of the gun- 
barrel without the fire, and pushing it forward 
when the cryolite had attained a maximum tempe- 
rature. The operation went on very well, the 
whole being allowed to cool in a current of hydro- 
gen. After the treatment with water, in which 
the sodium fluoride dissolved very slowly, I ob- 
tained a black powder, consisting for the most part 
of iron. Its solution in HC1 gave small evidence 
of Al. The small amounts I obtained, however, 
should not deter others from making these experi- 
ments. These are the results of first experiments 
on which I have not been able to expend much 
time. Now that cryolite can be procured at so 
moderate a price, and sodium, by Deville's improve- 
ments, will in future become so much cheaper, it is 
in the power of every chemist to engage in the 
preparation of aluminium, and I have no doubt 
that in a short time methods will be found afford- 
ing a much more profitable result. 

" For the rest, I am of opinion that cryolite is the 
best adapted of all the compounds of aluminium 
for the preparation of this metal. It deserves the 
preference over Al 2 Cl 6 .2XaCl or A1 2 C1 6 , and it might 
still be employed with great advantage even if its 
price were to rise considerably. The attempts at 
preparing aluminium direct from A1 2 3 have as 



yet been unattended with success. Potassium and 
sodium appear only to reduce metallic oxides when 
the potash and soda produced are capable of forming 
compounds with a portion of the oxide remaining 
as such. Pure potash and soda, with whose pro- 
perties we are very slightly acquainted, do not 
appear to be formed in this case. Since, however, 
alumina combines so readily with the alkalies to 
form aluminates, one would be inclined to believe 
that the reduction of APO 3 by the alkali metals 
should succeed. But even were it possible to ob- 
tain the metal directly from A1 2 3 , it is very prob- 
able that cryolite would long be preferred should 
it remain at a moderate price, for it is furnished 
by nature in a rare state of purity, and the alumi- 
nium is combined in it with sodium and fluorine 
only, which exercise no prejudicial influence on the 
properties of the metal, whereas A1 2 3 is rarely 
found in nature in a pure state and in a dense, 
compact condition, and to prepare A1 2 3 on a large 
scale, freeing it from those substances which would 
act injuriously on the properties of the metal, 
would be attended with great difficulty. 

" The buttons of aluminium which I have pre- 
pared are so malleable that they may be beaten 
and rolled out into the finest foil without cracking 


on the edges. They have a strong metallic lustre. 
Some small pieces, not globular, however, were 
found in the bottom of the crucible, and occasion- 
ally adhering to it, which cracked on being ham- 


mered, and were different in color and lustre from 
the others. They were evidently not so pure as 
the greater number of the globules, and contained 
iron. On sawing through a large button weighing 
3.8 grms., it could readily be observed that the 
metal for about half a line from the exterior was 
brittle, while in the interior it was soft and malle- 
able. Sometimes the interior of a globule contained 
cavities. AVith Deville, I have occasionally observed 
aluminium crystallized. A large button became 
striated and crystalline on cooling. Deville believes 
he has observed regular octahedra, but does not 
state this positively. According to my brother's 
examination, the crystals do not belong to any of 
the regular forms. As I chanced on one occasion 
to attempt the fusion of a large, flattened-out but- 
ton of rather impure aluminium, without a flux, I 
observed, before the heat was sufficient to fuse the 
mass, small globules sweating out from the surface. 
The impure metal being less fusible than pure 
metal, the latter expands in fusing and comes to 
the surface." 

Such were the results given to the world by H. 
Rose. After their publication, many minds were 
turned towards this field, and it was discovered 
that some six months previously Dr. Percy had 
accomplished the same results, and had even shown 
them to the Royal Institution, but with the singu- 
lar fact of exciting very little attention. These 
facts are stated at length in the following paper, 


written by Allan Dick, Esq., which appeared in 
November, 1855, two months after the publication 
of H. Rose's paper : * 

"In the last number of this magazine was the 
translation of a paper by H. Rose, of Berlin, de- 
scribing a method of preparing aluminium from 
cryolite. Previously, at the suggestion of Dr. 
Percy, I had made some experiments on the same 
subject in the metallurgical laboratory of the 
School of Mines, and as the results obtained agree 
very closely with those of Mr. Rose, it may be 
interesting to give a short account of them now, 
though no detailed description was published at 
the time, a small piece of metal prepared from 
cryolite having simply been shown at the weekly 
meeting of the Royal Institution, March 30, 1855, 
accompanied by a few words of explanation by 

" Shortly after the publication of Mr. Deville's 
process for preparing aluminium from A1 2 C1 6 , I 
tried, along with Mr. Smith, to make a specimen 
of the metal, but we found it much more difficult 
to do than Deville's paper had led us to antici- 
pate, and had to remain contented with a much 
smaller piece of metal than we had hoped to obtain. 
It is, however, undoubtedly only a matter of time, 
skill, and expense to join successful practice with 
the details given by Deville. Whilst making 

* Phil. Mag., Nov. 1855. 


these experiments Dr. Percy had often requested 
us to try whether cryolite could be used instead of 
the chlorides, but some time elapsed before we 
could obtain a specimen of the mineral. The first 
experiments were made in glass tubes sealed at one 
end, into which alternate layers of finely powdered 
cryolite and sodium cut into small pieces were 
introduced, and covered in some instances with a 
layer of cryolite, in others by KaCl. The tube 
was then heated over a gas blowpipe for a few 
minutes till decomposition had taken place and 
the product was melted. When cold, on breaking 
the tube, it was found that the mass was full of 
small globules of aluminium, but owing to the 
specific gravity of the metal and flux being nearly 
alike, the globules had not collected into a button 
at the bottom. To effect this, long continued 
heat would be required, which cannot be given in 
glass tubes owing to the powerful action of the 
melted fluoride on them. To obviate this difficulty 
a platinum crucible was lined with magnesia by 
ramming it in hard, and subsequently cutting out 
all but a lining. In this, alternate layers of cryolite 
and sodium were placed, with a thickish layer of 
cryolite on top. The crucible was covered with a 
tight-fitting lid, and heated to redness for about 
half an hour over a gas blowpipe. When cold it 
was placed in water, and after soaking for some 
time the contents were dug out, gently crushed in 
a mortar, and washed by decantation. Two or 


three globules of aluminium, tolerably large con- 
sidering the size of the experiment, were obtained, 
along with a large number of very small ones. 
The larger ones were melted together under KOI. 
Some experiments made in iron crucibles were not 
attended with the same success as those of Rose, 
no globules of any considerable size remained in 
the melted fluorides ; the metal seemed to alloy on 
the sides of the crucible, which acquired a color 
like zinc. It is possible that this difference may 
have arisen from using a higher temperature than 
Rose, as we made these experiments in a furnace, 
not over the blowpipe. Porcelain and clay cruci- 
bles were also tried, but laid aside after a tew ex- 
periments, owing to the action of the fluorides 
upon them, which in most cases was sufficient to 
perforate them completely." 

The above papers, Rose's and Dick's, contain all 
the published researches with cryolite until Deville's 
attention was turned towards it. He then took 
up the subject with his accustomed thoroughness. 
The following pages are taken from his ' De 1' Alu- 
minium,' the subject not being given in its entirety, 
but only the most important points. He published 
the first account of these researches in ' Ann. de 
Chem. et de Phys.' [3], xlvi. 451 :- 

" I have repeated and confirmed all the experi- 
ments of Dr. Percy and H. Rose, using the specimens 
of cryolite which I obtained from London through 
the kindness of MM. Rose and Hofmann. I have, 


furthermore, reduced cryolite mixed with !N"aCl by 
the battery, and I believe that this will be an ex- 
cellent method of covering with aluminium all the 
other metals, copper in particular. Anyhow, its 
fusibility is considerably increased by mixing it 
with A1 2 C1 6 .2KC1. Cryolite is a double fluoride of 
aluminium and sodium, containing 13 per cent. 
Al, 32.5 per cent. Xa, and 54.5 per cent. F. Its 
formula is Al 2 F 6 .6NaF. I have verified these facts 
myself by many analyses." 

Deville then gives a description of methods of 
making cryolite artificially, which is unnecessary 
to repeat here, for natural cryolite is so cheap that 
these methods are of no practical importance. He 
continues : 

"In reducing the cryolite I placed the finely-pul- 
verized mixture of cryolite and XaCl in alternate 
layers with sodium in a porcelain crucible. The 
uppermost layer is of pure cryolite, covered with 
XaCl. The mixture is heated just to complete fu- 
sion, and, after stirring with a pipe-stem, is let cool. 
On breaking the crucible, the aluminium is often 
found united in large globules easy to separate from 
the mass. The metal always contains silicon, which 
increases the depth of its natural blue tint and 
hinders the whitening of the metal by nitric acid, 
because of the insolubility of the silicon in that 
acid. M. Rose's metal is very ferruginous. I have 
verified all M. Rose's observations, and I agree 
with him concerning the return of metal, which I 


have always found very small. There are always 
produced in these operations brilliant flames, which 
are observed in the scoria floating on the alumin- 
ium, and which are due to gas burning and 
exhaling a very marked odor of phosphorus. In 
fact, P 2 6 exists in cryolite, as one may find by 
treating a solution of the mineral in sulphuric acid 
with molybdate of ammonia, according to H. 
Rose's reaction. 

"The facility with which aluminium unites in 
fluorides is due without doubt to the property which 
these possess of dissolving the alumina on the surface 
of the globules at the moment of their formation, 
and which the sodium is unable to reduce. I had 
experienced great difficulty by obtaining small 
quantities of metal poorly united, when I reduced 
the Al 2 Cl 6 .2]N"aCl by sodium ; M. Ramrnelsberg, who 
often made the same attempts, tells me he has had a 
like experience. But, I am assured by a scrupulous 
analysis that the quantity of metal reduced by the 
sodium is exactly that which theory indicates, 
although after many operations there is found only 
a gray powder, resolving itself under the micro- 
scope into a multitude of small globules. The fact 
is simply that Al 2 Cl 6 .2NaCl is a very poor flux 
for aluminium. MM. Morin, Debray, and myself 
have undertaken to correct this bad eflect by the 
introduction of a solvent for the A1 2 3 into the 
saline slag which accompanies the aluminium at 
the moment of its formation. At first, we found 


it an improvement to condense the vapors of A1 2 C1 6 , 
previously purified by iron,-directly in NaCl, placed 
for this purpose in a crucible and kept at a red 
heat. We produced in this way , from highly colored 
material, a double chloride very white and free from 
moisture, and furnishing on reduction a metal of 
fine appearance. We then introduced fluorspar 
(CaF 2 ) into the composition of the mixture to be 
reduced, and we obtained good results with the 
following proportions : 

Al*Cl 6 .2NaCl .... 400 grammes. 

NaCl 200 

CaF 2 200 " 

Na . . . . . . 75 to 80 " 

The double chloride ought to be melted and heated 
almost to low red heat at the moment it is em- 
ployed, the NaCl calcined and at a red heat or 
melted, and the CaF 2 pulverized and well dried. 
The double chloride, NaCl and CaF 2 are mixed and 
alternated in layers in the crucible with sodium. 
The top layer is of the mixture, and the cover is 
XaCl. Heat gently, at first, until the reaction ends, 
and then to a heat about sufficient to melt silver. 
The crucible, or at least that part of it which con- 
tains the mixture, ought to be of a uniform red tint, 
and the material perfectly liquid. It is stirred a 
long time and cast on a well-dried, chalked plate. 
There flows out first a very limpid liquid, colorless 
and very fluid, then a gray material, a little more 
pasty, which contains aluminium in little grains, 


and is set aside, and finally a button with small, 
metallic masses which of themselves ought to weigh 
20 grms. if the operation has succeeded well. On 
pulverizing and sieving the gray slag, 5 or 6 grms. of 
small globules are obtained, w r hich may be pressed 
together by an earthen rod in an ordinary crucible 
heated to redness. The globules are thus reunited, 
and when a sufficient quantity is collected the metal 
is cast into ingots. In a well-conducted operation, 
75 grms. of Na ought to give a button of 20 grms. 
and 5 grms. in grains, making a return of one Al 
from three of Na. Theory indicates one to two 
and a half, or 30 grms. of Al from 75 of Na. But 
all the efforts which have been made to recover from 
the insoluble slag the 4 or 5 grms. of metal not 
united but easily visible with a glass, have been so 
far unsuccessful: There is, without doubt, a knack, 
a particular manipulation on which depends the 
success of an operation which would render the 
theoretical amount of metal, but we lack it yet. 
These operations take place, in general, with more 
facility on a large scale, so that we may consider 
fluorspar as being suitable for serving in the manu- 
facture of aluminium in crucibles. We employed 
very pure fluorspar, and our metal was quite exempt 
from silicon. It is true that we took a precaution 
which is necessary to adopt in operations of this 
kind; we plastered our crucibles inside with a layer 
of aluminous paste, the composition of which has 
been given in ' Ann. de Chem. et de Phys.,' xlvi. 


195. This paste is made of calcined alumina and 
an aluminate of lime, the latter obtained by heating 
together equal parts of chalk and alumina to a high 
heat. By taking about four parts calcined alumina 
and one of aluminate of lime well pulverized and 
sieved, moistening with a little water, there is 
obtained a paste with which the inside of 'an 
earthen crucible is quickly and easily coated. The 
paste is spread evenly with a porcelain spatula, and 
compressed strongly until its surface has become 
well polished. It is allowed to dry, and then heated 
to bright redness to season the coating, which does 
not melt, and protects the crucible completely 
against the action of the aluminium and fluorspar. 
A crucible will serve several times in succession 
provided that the new material is put in as soon as 
the previous charge is cast. The advantages of 
doing this are that the mixture and the sodium are 
put into a crucible already heated up, and so lose 
less by volatilization because the heating is done 
more quickly, and the crucible is drier than if a new 
one had been used or than if it had been let cool. 
A new crucible should be heated to at least 300 
or 400 before being used. The saline slag contains 
a large quantity of calcium chloride, which can be 
washed away by water, and an insoluble material 
from which aluminium fluoride can be volatilized. 
" Yet the operation just described, which was a 
great improvement on previous ones, requires many 
precautions and a certain skill of manipulation to 


succeed every time. But, nothing is more easy or 
simple than to substitute cryolite for the fluorspar. 
Then the operation is much easier. The amount of 
metal produced is not much larger, although the 

-IT O 7 O 

button often weighs 22 grammes, yet if cryolite can 
only be obtained in abundance in a continuous sup- 
ply, the process which I will describe will become 
most economical. The charge is made up as before, 
except introducing cryolite for CaF 2 . In one of 
our operations we obtained, with 76 grrns. of sodi- 
um, a button weighing 22 grms. and 4 grms. in 
globules, giving a yield of one Al to two and ei^ht- 
tenths parts sodium, which is very near to that 
indicated by theory. The metal obtained was of 
excellent quality. However, it contained a little 
iron coming from the A1 2 C1 6 , W 7 hich had not been 
purified perfectly. Bat iron does not inj ure the prop- 
erties of the metal as copper does ; and, save a little 
bluish coloration, it does not alter its appearance or 
its resistance to physical and chemical agencies. 

"Process with cryolite alone: The process adopted 
in the works at Amfreville, near Rouen, directed 
by Tissier Bros., is the same as that described by 
Percy and Rose. The details which I give are 
taken from MM. Tissier's own account of their pro- 
cess." (Deville then gives the details of the process 
outlined by Rose (see p. 103), of reducing in iron 
crucibles ; which it is not necessary to repeat.) 

" I obtained a good specimen of commercial alu- 
minium thusextracted from cryolite ; and M. Demon- 


deur has been so kind as to make an analysis of it, 
with the following results: Si 4.4; FeO.8; A! 94.8. 
" M. Rose has recommended iron vessels for this 
operation, because of the rapidity with which alka- 
line fluorides attack earthen crucibles and so intro- 
duce considerable silicon into the metal. Unfortu- 
nately, these iron crucibles introduce iron into the 
metal. This is an evil inherent to this method, at 
least in the present state of the industry. The 
inconveniences of this method result in part from 
the high temperature required to complete the ope- 
ration, and from the crucible being in direct contact 
with the fire, by which its sides are heated hotter 
than the metal in the crucible. The metal itself, 
placed in the lower part of the fire, is hotter than 
the slag. This, according to my observations, is an 
essentially injurious condition. The slag ought to 
be cool, the metal still less heated, and the sides of 
the vessel Avhere the fusion occurs ought to be as 
cold as possible. The yield from cryolite, accord- 
ing to Rose's and my own observations, is also very 
small. M. Rose obtained from 10 of cryolite and 
4 of Xa about 0.5 of Al. This is due to the 
affinity of aluminium for fluorine, which must be 
very strong not only with relation to its affinity 
for sodium but even for calcium, and this affinity 
appears to increase with the temperature, as was 
found in my laboratory. Cryolite is convenient to 
employ as a flux to add to the mixture which is 
fused, especially when operating on a small scale; 



but it is fortunate that it is not indispensable, for 
no one would wish to establish an industry on the 
employment of a material w T hich is of uncertain 

We here close what Deville has written on the 
use of cryolite. The process was that used by 
Tissier Bros, at Rouen, but was finally abandoned 
there and the works closed. We find a little 
improvement on Deville's process suggested by 
Wohler,* in which he shows how to perform the 
reduction in an earthen crucible. The finely pul- 
verized cryolite is mixed with an equal weight of 
a flux containing 7 NaCI to 9 KC1. This mixture' 
is then placed in alternate layers with sodium in 
the crucible, 50 parts of the mixture to 10 of 
sodium, and heated gradually just to its fusing 
point. The metal thus obtained is free from 
silicon, but only one-third of the aluminium in the 
cryolite is obtained. In spite of the small yield, 
this method was used for some time by Tissier 
Bros. Cryolite has also been treated at ]^"anterre, 
by a different process, but the aluminium produced 
contained phosphorus. So, while the exclusive 
use of cryolite in the preparation of aluminium is 
now renounced, it has retained the office of a flux. 

Watts gives the following paragraph in connec- 
tion with the reduction of cryolite : "A peculiar 
apparatus for effecting the reduction of aluminium, 

* Ann. der Cbem. und Pharm. 99, 255. 


either from Al 2 Cl 6 .2NaCl or from cryolite, the 
object of which is to prevent loss of sodium by 
ignition, has been invented and patented by W. F. 
Gerhard.* It consists of a reverberatory furnace 
having two hearths, or of two crucibles, or of two 
reverberatory furnaces, placed one above the other 
and communicating by an iron pipe. In the lower 
is placed a mixture of sodium with the aluminium 
compound, and in the upper a stratum of !NaCl, or 
of a mixture of NaCl and cryolite, or of the slag 
obtained in a previous operation. This charge, 
when melted, is made to run into the lower furnace 
in quantity sufficient to completely cover the mix- 
ture contained therein, and so to protect it from 
the air. The mixture thus covered is reduced as 
by the usual operation." 

Watts thus summarizes the use of cryolite : 
" The chief inducement for using it as a source of 
aluminium is that it is a natural product obtained 
with tolerable facility, and enables the manufact- 
urer to dispense with the troublesome and costly 
preparation of Al 2 Cl 6 .2^"aCl. But the metal thus 
obtained is less pure than that obtained by other 
processes. If earthenware crucibles are used, the 
metal is contaminated with silicon, because the 
sodium fluoride produced acts strongly on the 
siliceous matter of the crucible, while if an iron 
crucible be used, the metal takes up some iron. 

* Eng. Pat. 1858, No. 2247. 


The best use of cryolite is as a flux in the prepara- 
tion of aluminium from Al 2 Cl 6 .2JN"aCl, in which 
case the slag is not sodium fluoride but aluminium 
fluoride, which acts but slightly on the containing 


I have now given the metallurgy of aluminium 
through what may be called its experimental stage 
up to its practical industrial manufacture. Up to 
this period, which I will place at about 1859, the 
object has been to produce the metal at any cost, 
only produce it. " To learn how" engrossed the 
attention of the investigators, who troubled them- 
selves very little about the ultimate cost. They 
must learn first how to do the thins: and afterwards 


devote their energies to cheapening the process 
discovered. But, in 1859, the works at Amfreville, 
near Rouen, under the direction of the Tissiers, is 
producing aluminium from cryolite; Morin & Co., 
at Nanterre, are making it, though not in such 
large quantities as Tissier, but they soon after 
move to Salindres, and set up so large a plant that 
a year or so afterwards the Tissiers were driven 
from the business. Such is then the state of the 
industry. We iind that in the next fifteen or 
twenty years very little advance is chronicled. At 
Salindres, the processes given by Deville were used 
somewhat improved and perfected, but yet the 


same processes. It is only within the last ten 
years that any improvements of a radical nature, 
such as Webster's, Frishmuth's, and Cowles, have 
been brought into the industry. 

So, from now on we will treat the subject in the 
order usually adopted in presenting it ; i. e., first 
give a short sketch of the metallurgy of sodium 
up to the present time, then a review of the manu- 
facture of alumina and its conversion into 
Al 2 Cl 6 .2XaCl, ending with a full description of the 
process as now carried on at Salindres, and a few r 
attempts which have been made to improve it. 
Afterwards, leaving the old Deville process and its 
improvements, I will give as full an account as I 
have been able to gather of the various methods 
proposed to produce aluminium without the use of 



As already observed, we will not go extensively 
into the metallurgy of this metal. Some years 
ago, in order to treat fully of the metallurgy of 
aluminium, it would have been as necessary to ac- 
company it with all the details of the manufacture of 
sodium as to give the details of the reduction of the 
aluminium, because the manufacture of the former 
was carried on solely in connection with that of the 
latter. But now sodium has come out of the list of 
chemical curiosities and has become an article of 
commerce, used for many other purposes than the 
reduction of aluminium, though that is still its 
chief use. So we regard the manufacture of sodium 
as a separate metallurgical subject, still intimately 
connected with that of aluminium, but yet so far 
distinct from it as to deserve a metallurgical trea- 
tise of its own. Moreover, the metallurgy of sodium 
is very much as Deville left it, it has been very 
little improved since then, and so almost all the 
details of its manufacture are to be found in Eng- 
lish in any good book on chemistry. To such 
works I refer the reader for fuller accounts than are 


given here. The following summary is taken prin- 
cipally from Mierzinski. 

Sodium was first isolated by Davy by the use of 
electricity in the year 1808.* Later, Gay Lussac 
and Thenard made it by decomposing at a very 
high temperature a mixture of Na 2 C0 3 and iron 
filings/)- On April 30, 1808, Curaudau announced 
that he had succeeded in producing potassium or 
sodium without using iron, simply by decomposing 
K 2 C0 3 or ^a 2 CO s by means of animal charcoal. 
Briinner continuing this investigation used instead 
of animal charcoal the so-called black flux, the pro- 
duct obtained by calcining crude tartar from wine 
barrels. He was the first to use the w rough t-iron 
mercury bottles. The mixture was heated white 
hot in a furnace, the sodium volatilized and was 
condensed in an iron tube screwed into the top of 
the flask, which projected from the furnace and 
was cooled with water. In Briinners experiments 
he only obtained three per cent, of the weight of 
the mixture as metallic sodium, the rest of the 
metal being lost as vapor. 

Donny and Mareskagave the condenser the form 
which with a few modifications it retains to-day. 
It was of iron, 4 millimetres thick, arid was made 
in the shape of a book, having a length of about 
100 centimetres, breadth 50, and depth 6 (see Fig. 
2). This form is now so well known that a further 

* Phil. Trans., 1808. 

| Recherches Physico-chemiques, 1810. 


description is unnecessary. With this condenser 
the greatest difficulty of the process was removed, 
and the operation could be carried on in safety. 

Fig. 2. 

This apparatus was devised and used by Donny and 
Mareska in 1854, with the supervision of Deville, 
and the whole process as used by them is the same 
that the Tissier Bros, took with them and operated 
at their works at Rouen, and their description ac- 
cords with that given by Deville, which is as fol- 
lows : 

The Na 2 C0 3 is first well dried at a high tempera- 
ture, then mixed with well dried pulverized char- 
coal and chalk, ground to the finest powder, the 
success of the operation depending on the fineness of 
this mixture. The proportions of these to use is 
various. One simple mixture is of 

Na2CO* 30 

Coal . . . ' . . . .13 

Chalk . . . . ".." . 5 

Coke 5 


Devil le recommends taking 

Coal . 
Chalk . 


The addition of chalk has the object of making the 
mixture less fusible and more porous, but has the 
disadvantage that the residue remaining in the re- 
tort after the operation is very impure, and it is 
impossible to add any of it to the succeeding charge ; 
and also, some of it being reduced to caustic lime 
forms caustic alkali with some Na'CO 8 , which is 
then lost. When the mixture is well made it is 
subjected to a preliminary calcination. This is 
done in cast-iron cylinders, two of which are placed 
side by side in a furnace and heated to redness (see 
Fig. 3). This is continued till all the moisture, 

Fig. 3. 

carbonic acid, and any carburetted hydrogen rforn 
the coal cease coming oft'. The mass contracts, be- 
comes white and somewhat dense, so that a larger 




amount of the mixture can now be treated in the 
retorts where the sodium is evolved. As soon as 
the outcorning gases burn with a yellow flame, 
showing sodium coming off, the calcination is 
stopped. The mixture is then immediately drawn 
out on to the stone floor of the shop, w T here it cools 
quickly and is then ready for the next operation. 
This calcination yields a mixture which without 
any previous reactions is just ready to evolve sodium 
when brought to the necessary temperature. This 
material is made into a sort of cylinder or cartridge 
and put into the decomposition retorts (see Fig. 4). 

Fig. 4. 

The charging should be done quickly. The final 
retorts are 120 centimetres long, 12 to 14 centime- 


tres diameter, with walls 10 to 30 millimetres thick. 
These are of wrought iron, since cast iron would 
not stand the heat. At each end this retort is 
closed with wrought-iron stoppers and made tight 
with fire-clay. Through one stopper leads the pipe 
to the condenser, the other stopper is the one re- 
moved when the retort is to be recharged. These 
retorts are placed horizontally in rows in a furnace. 
Usually four are placed in a furnace, preferably 
heated by gas, such as the Siemens regenerative 
furnace or Bicheroux's, these being much more eco- 
nomical. In spite of all these precautions the re- 
torts will be strongly attacked, and in order to pro- 
tect them from the destructive action of a white 
heat for seven or eight hours they are coated with 
some kind of fire-proof material. The best for 
this purpose is graphite, which is made into cylin- 
ders inclosing the retorts, and which can remain in 
place till the furnace is worn out. These graphite 
cylinders not only protect the iron retorts, but pre- 
vent the diffusion of the gaseous products of the 
reaction into the hearth, and so support the retorts 
that their removal from the furnace is easily ac- 
complished. Instead of these graphite cylinders 
the retorts may be painted with a mixture that 
melts at white heat and so enamels the outside. A 
mixture of alumina, sand, yellow earth, borax, and 
water-glass will serve very well in many cases. We 
would remark that the waste gases from this fur- 
nace can be used for the calcining of the mixture, or 


even for the reduction of the aluminium by sodium, 
where the manufacture of the former is connected 
with the making of the sodium. Donny and 
Mareska's condenser is the best to use. 

As for the reduction of the sodium, the retort is 
first heated to redness, during which the stopper 
at the condenser end of the retort is left off. The 
charge is then rapidly put in, and the stopper at 
once put in place. The reaction begins almost at 
once and the operation is soon under full headway, 
the gases evolved burning from the upper slit of 
the condenser tube with a flame a foot long. The 
gases increase in volume as the operation continues, 
the flame becoming yellower from sodium and so 
intensely bright as to be insupportable to look at. 
Now has come the moment when the workman 
must quickly adapt the condenser to the condenser 
tube projecting from the retort, the joint being 
greased with tallow or paraffine. The sodium 
collects in this in a melted state and trickles out. 
The length of the operation varies, depending on 
the intensity of the heat and the quantity of the 
mixture ; a charge may sometimes be driven over 
in two hours, and sometimes it takes eight. We 
can say, in general, that if the reaction goes on 
quickly a somewhat larger amount of sodium is 
obtained. The higher the heat used, however, the 
quicker the retorts are destroyed. The operation 
requires continual attention. From time to time, 
a workman with a prod opens up the neck of the 


condenser. But, if care is not taken the metal 
overflows : if this happens, the metal overflowing 
is thrown into some petroleum, while another man 
replaces the condenser with an empty one. The 
operation is ended when the evolution of gas ceases 
and the flame becomes short and feeble, while the 
connecting tube between the retort and condenser 


keeps clean and does not stop up. As soon as this 
occurs, the stopper at the charging end is removed, 
the charge raked out into an iron car, and a new 
charge being put in, the operation continues. 
After several operations the retorts must be well 
cleaned and scraped out. The sodium thus ob- 
tained is in melted bits or drops, mixed with carbon 
and Na 2 C0 3 . It must therefore be cleaned, which 
is done by melting it in a wrought-iron kettle 
under paraffin with a gentle heat, and then casting 
it into the desired shapes. The sodium is kept 
under a layer of oil or any hydrocarbon of high 
boiling point containing no oxygen. 

Deville says that the temperature necessary for 
the reduction of sodium from Na 2 C0 3 and carbon 
is not so high as is generally supposed. He says 
that it was M. Bivot's opinion that the retorts were 
not heated higher than the retorts at Veille-Mon- 
tague used for reducing zinc. Tissier gives the 
reaction as 

:N T a 2 C0 3 -f 2C = SCO 4- 2^a. 
The sodium is condensed, while the carbonic 



oxide, carrying over some sodium, burns at the 
end of the apparatus. This would all be very 
simple if the reaction of carbonic oxide on sodium 
near the condensing point did not complicate 
matters, producing a black, infusible deposit of 
Na?0 and C, which on being melted always gives 
rise to a loss of sodium. 

The foregoing is the process as perfected by 
Donny and Mareska, Deville, and Tissier. Only a 
few improvements have been made, the most im- 
portant are the following: 

R. Wagner* uses paraffin in preference to paraf- 
fin oil in which to keep the sodium after making 
it. Only pure paraffin which has been melted a 
long time on a water bath and all its water driven 
off can be used. The sodium to be preserved is 
dipped in the paraffin melted on a water bath and 
kept at no higher heat than 55, and the metal is 
thereby covered with a thick coat of paraffin 
which protects it from oxidation, and may then be 
put up in wooden or paper boxes. When the 
metal is to be used, it is easily freed from paraffin 
by simply warming it, since sodium melts at 95 
to 96 C. and the paraffin at 50 to 60. 

The reduction of K 2 CG 3 by carbon requires much 
less heat than that of Na 2 C0 3 , and, therefore, many 
attempts have been made to reduce potassium and 
sodium together, tinder circumstances where so- 

* Dingier, 1883, p. 252. 


dium alone would not be reduced. Dumas* added 
some K 2 C0 3 to the regular sodium mixture ; and 
separated the sodium and potassium from each 
other by a slow, tedious oxidation. R. Wagnerf 
made a similar attempt. He says that not only 
does the reduction of both metals from a mixture 
of K 2 C0 3 , Xa 2 C0 3 , and carbon work easier than 
Xa 2 C0 3 and carbon, but even caustic soda (XaOH) 
may be used with K 2 CO S and carbon. Also, the 
melting point of potassium and sodium alloyed is 
much lower than that of either one alone, in con- 
sequence of which their boiling point and the tem- 
perature required for reduction are lower. 

"W. Weldon calculated the cost of sodium as 
seven to eight marks per kilo. The greater part 
of this is for retorts in which the operation takes 
place, and which are so quickly destroyed that the 
replacing of them forms half the cost of the metal. 
Compare with p. 172. 

The latest announcement of advance in making 
sodium is from New York City, and is thus de- 
scribed in a New York paper: % 

" When sodium was reduced in price to $1.50 per 
pound, it was thought to have touched a bottom 
figure, and all hope of making it any cheaper seemed 
fruitless. This cheapening was not brought about 

* Handbuch der Angewandten Chemie, 1830, ii. 345. 

t Dingier, 143, 343. 

t New York World, May 16, 1886. 


by any improved or new process of reduction, but 
was owing simply to the fact that the aluminium 
industry required sodium, and by making it in 
large quantities its cost does not exceed the above- 
mentioned price. The retail price is now $4.00 
per pound. The process now used was invented 
by Briinner, in 1808, and up to the present time 
nothing new or original has been patented except 
three or four modifications of his process which 
have been adopted to meet the requirements of 
using it on a large scale. Mr. H. Y. Castner, whose 
laboratory is at 218 West Twentieth Street, New 
York, has the first patent ever granted on this sub- 
ject in the United States, and the only one taken 
out in the world since 1808. Owing to negotia- 
tions being carried on, Mr. Castner having filed 
applications for patents in various foreign countries, 
but not having the patents granted there yet, we 
are not at liberty to state his process fully. The 
metal is reduced and distilled in large iron cruci- 
bles, which are raised automatically through aper- 
tures in the bottom of the furnace, where they remain 
until the reduction is completed and the sodium 
distilled. Then the crucible is lowered, a new one 
containing a fresh charge is substituted and raised 
into the furnace, while the one just used is cleaned 
and made ready for use again. The temperature 
required is very moderate, the sodium distilling as 
easy as zinc does when being reduced. Mr. Cast- 
ner expects to produce it at 25 cents per pound, 


thus solving the problem of cheap aluminium, and 
with it magnesium, silicon, and boron, all of which 
depend on sodium for their manufacture. Thus 
the production of cheap sodium means much more 
than cheap aluminium. Mr. Castner is well known 
in New York as a chemist of good standing, and 
has associated with him Mr. J. H. Booth and Mr. 
Henry Booth, both well known as gentlemen of 
means and integrity." 

Mr. Benjamin, in a letter to the ' Engineering 
and Mining Journal,' gives the following details 
in addition to those above:* The pots used are 
cast iron, 8 inches in diameter and 14 inches deep. 
They are kept at bright red, or about 1000, at 
which temperature the decomposition takes place. 
Whereas, by previous processes only one-third of 
the sodium in the charge is obtained, Mr. Castner 
gets nearly all, for the pots are nearly entirely 
empty when withdrawn from the furnace. Thus 
the great items of saving are, two or three times 
as much metal extracted from a given amount of 
salt, and cheap cast-iron crucibles used instead of 
expensive wrought-iron retorts. 
The following are the claims which Mr. Castner 
makes in his patent : f 

Claim 1. In a process for manufacturing potas- 
sium or sodium, performing the reduction by diflus- 

* Eng. and Min. Journ., May 29, 1886. 
t U. S. Pat. No. 342,897, June 1, 1886. Hamilton Y. Cast- 
ner, New York. 


ing carbon in a body of alkali in a state of fusion 
at moderate temperatures. 

2. Performing the reduction by means of the 
carbide of a metal or its equivalent. 

3. Mechanically combining a metal and carbon 
to increase the weight of the reducing material, 
and then mixing this product with the alkali and 
fusing the latter, whereby the reducing material is 
held in suspension throughout the mass of fused 

4. Performing the deoxidation by the carbide of 
a metal or its equivalent. 

We learn later that Mr. Castner cokes a mixture 
of fine iron and gas-tar, grinds the coke, and uses 
this as the reducing material ; caustic soda is used 
on account of its low fusing point. 


Mierzinski : In order to lower the cost of sodium 
efforts have been made to obtain it by means of 
electricity. Davy has shown that its production 
in this way is possible, for he first obtained the 
metal by electrolizing a solution of Na 2 C0 3 . P. 
Jablochoff uses the following arrangement to de- 
compose Nad or KC1 : 

The arrangement is easily understood. The salt 
to be decomposed is fed in by the funnel into the 
kettle heated by a fire beneath. The positive pole 
evolves chlorine gas, and the negative pole evolves 



vapor of the metal, for, as the salt is melted, the 
heat is sufficient to vaporize the metal liberated. 
The gas escapes through one tube and the metallic 

Fig. 5. 

anrrm ?** 

vapor by the other. The vapor is led into a con- 
denser and solidified. 



I DO not propose to give here all the methods 
.which have been employed to get good clean alu- 
mina (APO 3 ), but only those which may be recom- 
mended as being practical and economical on a 
large scale, not repeating the methods used at Sal- 
indres or by Mr. Webster, which will be found in 
connection with the full description of the processes 
used at Salindres and Birmingham. Most of the 


following is from Mierzinski, and may be taken as 
representing the present state of the industry. 

By igniting an alum salt, as ammonia alum, there 
remains either a white powder or shining, sticky 
pieces which are very hard and dissolve with dif- 
ficulty in weak acid or in concentrated solutions of 
alkali. Large quantities of this alumina may be 
obtained by calcining the salt in an oven similar in 
its principal details to a soda furnace. 

Mierzinski then gives Mr. Webster's process of 
mixing the powdered alum with coal-tar, etc., 
which is given in full in Part IX. 

Tilghman decomposes commercial sulphate of 
alumina, AP(S0 4 ) 3 .18H 2 0, by filling a red-hot fire- 


clay cylinder with it. This cylinder is lined inside 
with a magnesia fettling, is kept at a red heat, the 
sulphate put in in large lumps, and steam is passed 
through the retort, carrying with it vapor of XaCl. 
This last arrangement is effected by passing steam 
into a cast-iron retort in which ^N"aCl is kept melted, 
and as the steam leaves this retort it carries vapor 
of the salt with it. It is preferable, however, to 
make a paste of the sulphate of alumina and the 
sodium chloride, forming it into small hollow cyl- 
inders, which are well dried, and then the fire-clay 
cylinder filled with these. Then, the cylinder being 
heated to whiteness, highly superheated steam is 
passed over it. The HC1 which is formed is 
caught in a condensing apparatus, and there remains 
a mass of aluminate of soda, which is moistened 
with water and treated with a current of carbon 
dioxide and steam. By washing the mass, the soda 
goes into solution and hydrated alumina remains, 
which is washed well arid is ready for use. 

Most of the alumina is now made from the 
natural aluminous earths, beauxite and cryolite, 
the occurrence and properties of which have been 
already described. The manufacture from beauxite 
is fully described in the account of the process used 
at Salindres, on p. 158. "We will give here the 
modern methods of making it from cryolite. 



Dry Way. The cryolite is pulverized, an easy 
operation, and to every 100 parts, 130 to 150 parts of 
chalk are added, and a suitable quantity of fluorspar 
is also used, which remains in the residue on wash- 
ing after ignition. More chalk is used than is theo- 
retically necessary, in order to make the mass less 
fusible and keep it porous. But, to avoid using 
too much chalk merely for this purpose, a certain 
quantity of coke may be put into the mixture. It 
is of-the first importance that the mixture be very 
intimate and finely pulverized. It is of greater 
importance that the mixture be subjected to just 
the proper w T ell-regulated temperature while being 
calcined. The cryolite will melt very easily, but 
this is to be avoided. On this account, the calci- 
nation cannot take place in an ordinary smelting 
furnace, because, in spite of stirring, the mass will 
rnelt at one place or another, while at another part 
of the hearth it is not even decomposed, because 
the heat at the fire-bridge is so much higher than 
at the farther end of the hearth. Thomson con- 
structed a furnace for this special purpose (see 
Figs. 6 and 7), in which the flame from the fire 
first went under the bed of the furnace, then over 
the charge spread out on the bed, and finally in a 
flue over the roof of the hearth. The hearth has 
an area of nearly 9 square metres, being 4 me- 
tres long and 2.5 metres w r ide. It is charged 



twelve times each day, each time with 500 kilos of 
mixture, thus roasting 6000 kilos daily, with a 

Fig. 6. 

consumption of 800 kilos of coal. The waste heat 
of the gases escaping from the furnace is utilized 

for drying the soda solution to its crystallizing 
point, and the gases finally pass under an iron 
plate on which the chalk is dried. In this fur- 


nace the mass is ignited thoroughly without a hit 
of it melting, so that the residue can be fully 
washed with water. The reaction commences at 
a gentle heat, hut is not completed until a red heat 
is reached. Here is the critical point of the whole 
process, since a very little raising of the tempera- 
ture ahove a red heat causes it to melt. However, 
it must not he understood that the forming of 
lumps is altogether to be avoided. These lumps 
would be very hard and unworkable when cold, 
but they can be broken up easily while hot, so 
that they may be drawn out of the furnace a few 
minutes before the rest of the charge is removed, 
and broken up while still hot without any trouble. 
The whole charge, on being taken out, is cooled 
and sieved, the hard lumps which will not pass the 
sieve arc ground in a mill and again feebly ignited, 
when they will become porous and may be easily 
ground up. However, the formation of these 
lumps can be avoided by industrious stirring of 
the charge in the furnace. A well-calcined mix- 
ture is porous, without dust and without lumps 
which are too hard to be crushed between the 
fingers. We would here remark that mechani- 
cal furnaces of similar construction to those used 
in the manufacture of soda, potash, sulphate of 
soda, etc., are more reliable and give the best 
results if used for this calcination. The mixture, 
or ashes, as the workmen call it, is drawn still hot, 
and washed while warm in conical wooden boxes 
with double bottoms, or the box may have but one 


bottom, with an iron plate about 76 millimetres 
above it. A series of such boxes, or a large appa- 
ratus having several compartments, may be so 
arranged that the washing is done methodically, 
i. ., the fresh water comes first in contact with a 
residue which is already washed nearly clean, and 
the fresh charge is washed by the strong liquor. 
This is known as the " Lessiveur methodique," 
and an apparatus constructed especially for this 
purpose is described in Dingier 186, 370, by P. J. 
Havrez, but the subject is too general and the de- 
scription too long to be given here. A very suit- 
able washing apparatus is also that of Schank, 
used in the soda industry for washing crude soda, 
and described in ' Lunge's Handbook of the Soda 
Industry,' Book II. p. 410. Since the ashes are 
taken warm from the furnace the washing water 
need not be previously heated, but the final wash- 
water must be warmed as the ashes have been 
cooled down by the previous washings. As soon 
as the strong liquor does not possess a certain 
strength, say 20 B., it is run over a fresh charge 
and so brought up. The solution contains sodium 

Xow, whether the sodium aluminate solution is 
made from beauxite or cryolite, it is treated further 
in the same way in either case to get the hyd rated 
alumina and the soda solution. Carbon dioxide is 
next passed through the solution. 

The carbon dioxide necessary for precipitating the 


by d rated alumina may be made in different ways. 
The gases coming from the furnace in calcining the 
cryolite might be used if they were not contaminated 
with dust ; and there is also the difficulty that ex- 
hausting the gases from the furnace would interfere 
with the calcination. It has also been recommended 
to use the gases from the fires under the evapora- 
ting pans, by exhausting the air from the flues and 
purifying it by washing with water. This can 
only be done where the pans are fired with wood 
or gas. However, the lime-kiln is almost exclu- 
sively used to furnish this gas. The kiln used is 
shaped like a small blast furnace. Leading in at the 
boshes are two flues from five fire-places built in 
the brickwork of the furnace, and the heat from 
these calcines the limestone. The gases are taken 
off by a cast-iron down-take at the top. At the 
bottom of the furnace, corresponding with the tap 
hole in a blast furnace, is an opening, kept closed, 
from which lime is withdrawn at intervals. A 
strong blast is blown in just above the entrance of 
the side flues, and by keeping up a pressure in the 
furnace, leakings into it may be avoided. The 
gas is sucked away from the top by a pump, which 
forces it through a cleaning apparatus constructed 
like a wash bottle, and it is then stored in a ga- 
someter. Instead of the pump, a steam aspirator 
may be used, which is always cheaper and takes up 
less room. 

The precipitation with CO 2 is made by simply 


forcing it through a tube into the liquid. The 
apparatus used at Salindres is one of the most im- 
proved forms. (See p. 163.) The precipitate is 
granular, and settles easily. However, it is not 
pure hydrated alumina, hut a compound of alumina, 
soda, carbonic acid, and water, containing usually 
about 45 per cent, APO 3 , 20 per cent, Na^O 3 , and 
35 per cent, H 2 0. The sodium carbonate can be 
separated by long-continued boiling with water, 
but by this treatment the alumina becomes very 
gelatinous and very difficult of further treatment. 
The precipitate was formerly separated on linen 
filters, but centrifugal machines are now preferred. 
The evaporated solution gives a high grade of car- 
bonate of soda free from iron. The heavy residue 
which is left after the ashes have been lixiviated 
consists of Fe*0 3 , CaO, undecomposed cryolite, and 
aluminate of Na, and has not been used for any- 

According to Lo wig's experiments, the solution 
of sodium aluminate can be precipitated by cal- 
cium, barium, strontium, or magnesium, hydrates, 
forming caustic soda and hydrated alumina, the 
latter being precipitated with the CaO, BaO, SrO, 
or MgO. The precipitate is washed by decantation 
and then divided into two portions, one of which 
is dissolved in HC1, the other made into a mush 
with water and gradually added to the solution of 
the other half until the nitrate shows only a very 
little APO 3 in solution. CaCP, EaCP, SrCP, or 


MgCl 2 has been formed, and the alumina all pre- 

Wet way. The decomposition of cryolite in the 
wet way is operated as follows: The finely 
powdered cryolite is boiled with dried burnt lime 
in the proportion of three parts cryolite to two of 
lime. There results a precipitate of calcium fluor- 
ide, CaF 2 , while sodium aluminate is in the 
solution. The reaction takes place quite easily. 
The solution is settled, washed by decaritation, 
and these washings put with the strong solution 
first poured off; the next washings are reserved 
for the fresh wash-water of another operation. 
The solution of sodium aluminate is then boiled 
with a quantity of cryolite equal to the amount 
first used, when sodium fluoride is formed and 
alumina precipitated. This operation is in noway 
difficult, only requiring a little more attention 
than the first. The alumina thus made is very 
finely divided. The reactions involved are : 

Al 2 F 6 .6^N T aF + 6CaO= AP0 3 .3^"a 2 4- 6CaF 2 . 
Al 2 F 6 .6STaF + Al 2 3 .3Ta 2 + 6H 2 0= 2(A1 2 3 .3H 2 0) 
+ 121S T aF. 

During this last operation it is best to add an 
excess of cryolite, and keep the liquid in motion 
to prevent the cryolite from caking at the bottom. 
Lead is the best material to make these precipitat- 
ing tanks of, since iron would contaminate the 
alumina. The precipitate is washed as in the 


previous operation. The solution of sodium fluor- 
ide, XaF, is boiled with the requisite quantity of 
burnt lime, which converts it into caustic soda, 
KaOH, which is separated from the precipitated 
CaF 2 by decantation and washing. The solution 
is evaporated down to a concentrated solution of 
XaOH, or to dryness, as desirable. The lime used 
should be as pure and free from iron as possible, to 
avoid contaminating the alumina. 

Alumina may also be obtained from alum stone 
or alum shales; by converting these into alums or 
into Al 2 (S0 4 ) 3 Aq. by any of the well-known 
methods of alum-makers, and then the alumina 
made by calcining this salt, as given on p. 144. 



SINCE the cost of the aluminium chloride is 
equal to the cost of the sodium used, in making 
aluminium, many attempts have been made to 
cheapen its manufacture from alumina, but with- 
out much success. Mr. Frishmuth, of Philadel- 
phia, claims that he has lowered the cost of alum- 
inium principally by making the APCl 6 much 
cheaper than before. Mr. Webster's process, 
which has been applied on such a large scale, is 
altogether concerned with producing the APCl 6 
cheaply, not a word being said about improve- 
ments in making the sodium. However, with 
these exceptions, and possibly one or two others 
which will be found further on, the making of 
these chlorides has remained much as Deville 
left it. The description of their manufacture as 
conducted at Salindres is the only account given 
by Mierzinski, and so that may be taken as the 
process now in general use, especially in Europe. 
It will be found on p. 166. I add here just a few 
words to Fremy's description of the process, which 
may serve to render his description more exact : 


Mierzinski says that when the double chloride 
is to be made, special importance is to be attached 
to using materials free from iron in preparing the 
alumina, as iron cannot be removed from A1 2 C1 6 .- 
2XaCl as easily as from A1 2 C1 6 . Mierzinski also 
devotes some space to descriptions of chlorine 
generators, but that is a separate subject, full de- 
scriptions of which can be found in any good work 
on practical chemistry. 

There have been a few attempts to make these 
chlorides in different ways from that used in 
Deville's process. I find two such processes, 
which, however, cannot have been much of an 
improvement on Deville's, or else they would have 
supplanted it. 

M. Dullo makes the following observations on 
the production of APC1 6 direct from clay: * 

"Up to the present time the A1 2 C1* necessary to 
the production of aluminium has been prepared by 
treating cryolite or beauxite, calcining them with 
carbonate of soda, and neutralizing directly with 
HOI or CO 2 the alu initiate of soda formed. This 
process may be simplified, and the APC1 6 obtained 
much more easily, by direct treatment of clay. 
For this purpose a good clay, free from iron and 
sand, is mixed with enough water to make a thick 
pulp, to which is added !N~aCl and pulverized 
carbon. For every 100 parts of dry clay there are 

* Bull, de la Soc. Chem. 1860, vol. T. p. 472. 


taken 120 parts XaCl and 30 of carbon. The mix- 
ture is dried and broken up into small fragments, 
which are then introduced into a red-hot retort 
traversed by a current of chlorine. Carbonic 
oxide is disengaged, while at the same time APC1 6 
and a little SiCl 4 are formed. It is not necessary 
that the chlorine should be absolutely dry, it may 
be employed just as it comes from the generator. 
The gas is absorbed very rapidly, because between 
the aluminium and silicon there are reciprocal 
actions under the influence of which the chemical 
actions are more prompt and energetic. The 
aluminium having for chlorine a greater affinity 
than silicon has, A1 2 C1 6 is first formed, and it is 
only when all the aluminium is thus transformed 
that any SiCl 4 is formed. When SiCl 4 begins to 
form the operation is stopped, the incandescent 
mixture is taken out of the retort and treated 
with water. The solution is evaporated to dryness 
to separate out a small quantity of silica, SiO 2 , 
which is in it, the-residue is taken up with water, 
and the Al 2 ClV2NaCl remains when the filtered 
solution is evaporated to dryness. These succes- 
sive solutions and evaporations might probably be 
suppressed, especially if only enough chlorine is 
passed over the incandescent clay to just convert all 
the aluminium into APC1 6 , in which case no SiCl 4 
will be formed, and therefore no soluble silica can 
exist in the solution to contaminate the APC1 6 or 


impede its reduction. M. Dullo recommends re- 
ducing the Al f ClV2]$raCl by zinc. See Part X. 

' Chemical News/ 1878, p. 307, contains a short 
account of an improved method of producing 
A1*C1 6 , which consists essentially in passing vapors 
of hydrochloric acid, HC1, and carbon disulphide, 
CS*, simultaneously over heated alumina or clay* 
The CS 2 changes it into aluminium, sulphide, 
A1 2 S 8 , and the HC1 converts this into Al'Cl 6 , 
which distils. 




We will now give the actual preparation at Salin- 
dres,* with the latest improvements which it has 
received in practice. Aluminium is there regularly 
prepared at the works of the Chemical Manufac- 
turing Company of Alais and Camargue, the old 
firm of Henry Merle & Co., new firm A. R. Pechi- 
ney & Co. 

The principal chemical reactions on which this 
process rests are the following : 

Formation of aluminate of soda by calcining 
beauxite with Na 2 C0 3 

(AlFe) 2 3 .2H 2 + 3a 2 C0 3 = Al 2 3 .33Ta 2 + Fe 2 3 

Formation of alumina by precipitating the alu- 
minate of soda with a current of carbon dioxide 

Al 2 3 .3ISra 2 + SCO 2 + 3II 2 = A1 2 3 .3H 2 -h 

Formation of Al 2 Cl 6 .2^s T aCl by the action of 
* Fremy's Ency. Chem., M. Margottet. 


chlorine on a mixture of alumina, carbon, and sodi- 
um chloride 

APO 3 + 30 + 2NaCl + 601= Al 2 CK2NaCl + SCO. 

Reduction of this double chloride by sodium. 
Al 2 CR2XaCl + 6a = 2 Al + SXaCl. 

The primary material then to furnish the alumin- 
ium is beauxite. It will be seen that to obtain 
the metal it is necessary to proceed successively 
through the following operations: 

I. Preparation of the aluminate of soda and so- 
lution of this salt to separate it from the ferric 
oxide contained in the beauxite. 

II. Precipitation of hyd rated alumina from the 
aluminate of soda by a current of carbon dioxide; 
washing the precipitate. 

III. Preparation of a mixture of alumina, car- 
bon, and salt, drying it, and then treating with 
gaseous chlorine to obtain the double chloride of 
aluminium and sodium. 

IV. Lastly, treatment of this chloride by sodium 
to obtain aluminium. 

We will now review these operations as practi- 
cally carried out in detail. We will not consider 
the preparation of the crude materials as chlorine, 
sodium, etc., which is spoken of elsewhere. 

I. Preparation of the Aluminate of Soda. 

The aluminate to serve for the preparation of 
Al 2 Cl 6 .2XaCl was first obtained by the calcination 


of ammonia alum. At Salindres this was with- 
drawn and beauxite used, a material consisting of 
sesqui-oxide of iron aad aluminium in varying pro- 
portions, with two molecules of water and a little 
silica. It is redder the more iron it contains. 
Beauxite is plentiful enough in the south of France, 
principally in the departments of Herault, Bouches- 
du-Rhone, and Yar. That used at Salindres comes 
from Yar. It contains at least seventy-five per 
cent, alumina. To separate the alumina from Fe 2 3 , 
it is treated with carbonate of soda, under the in- 
fluence of a sufficiently high temperature, the A1 2 3 
displacing the CO 2 and forming alurninate of soda, 
Al 2 3 .3N"a 2 0, while the Fe 2 3 remains unattacked. 
A simple washing with water then permits the 
separation of the Al 2 3 .31^a 2 from the insoluble 
Fe 2 3 . The beauxite is first finely pulverized by 
means of a vertical mill-stone, then intimately 
mixed with some Na 2 C0 3 . The mixture is made 
for one operation, of 

480 kilos beauxite. 

300 " Na 2 CO 3 of 90 alkali degrees. 

This mixture is introduced into a reverberatory 
furnace, resembling in form a soda furnace, and 
which will 'bear heating strongly. The mass is 
stirred from time to time, and it is kept heated 
until all the carbonate has been attacked, which is 
recognized by a test being taken which does not 
effervesce with acids. The operation lasts from 
five to six hours. 


The aluminate thus obtained is separated from 
Fe 2 3 by a washing with warm w r ater. This wash- 
ing is made at first with a feeble solution which has 
served for the complete exhaustion of the preceding 
charge, which was last washed with pure water, 
forming thus this feeble solution. This gives, on 
the first leaching, solutions of aluminate concen- 
trated enough to be called strong liquor, which are 
next treated by the current of CO 2 to precipitate 
the hyd rated alumina. The charge is next washed 
with pure water, w r hich completely removes the 
aluminate ; this solution is the weak liquor, which 
is put aside in a special tank, and used as the first 
leaching liquor on the next charge treated. This 
treatment takes place in the following apparatus 
(see Fig. 8) : B is a sheet-iron vessel, in the middle 
of which is a metallic grating>,F, on which is held 
all round its edges, by pins^ a cloth, serving as a 
filter. The upper part of this vessel is called sim- 
ply the filter. A ought to be closed by a metallic 
lid held on firmly by bolts. To work the apparatus, 
about 500 kilos of the charge to be washed is 
placed on the filter cloth, the lid is closed, then the 
steam-cock / of the reservoir A is opened. In A 
is the weak solution from the last washing of the 
preceding charge. The pressure of the steam 
makes it rise by the tube Tinto the filter; another 
jet of steam, admitted by the cock 6, rapidly 
warms the feeble liquor as it soaks into the charge. 
After filtering through, the strong liquor is drawn 




off by turning the stopcock Cr. The weak solu- 
tion of the reservoir A is put into the filter in 

Fig. 8. 

t.VYTYf> (Ji 

successive portions, and not all at once ; and after 
each addition of solution has filtered through, its 
strength in B. is taken, before any more solution 
is run in ; then, when the solution marks 3 to 4, 
it is placed in the special tank for weak liquor, 
with all that comes through afterwards. Just 


about this time, the weak liquor of the reservoir 
A is generally all used up, and is replaced by pure 
water introduced by the tube d. All the solutions 
which filtered through, marking over 3 to 4 B., 
are put together, and form the strong liquor which 
marks about 12 B. This extraction of the alu- 
minate being completed by the pure w r ater, the 
residue on the filter is taken out, and a new opera- 
tion may be commenced. 

II. Preparation of the Alumina. 

The strong liquor is introduced into a vessel 
having an agitator, w T here a strong current of CO 2 
may precipitate the A1 2 3 from it. The gas is 
produced by small streams of hydrochloric acid 
continuously falling on some limestone contained 
in a series of earthenware jars. The precipitation 
vessel is called a baratte. The CO 2 after having 
passed through a washing flask, is directed to a 
battery of three barattes, where the precipitation 
is worked methodically, so as to precipitate com- 
pletely the alumina of each baratte, and utilize at 
the same time all the carbon dioxide produced. 
In order to do this, the gas always enters first into 
a baratte in which the precipitation is nearest com- 
pletion, and arrives at last to that in which the 
solution is freshest. When the gas is not all ab- 
sorbed in the last baratte, the first is emptied, for 
the precipitation in it is then completed, and it is 



made the last of the series, the current being now 
directed first into the baratte which was previously 
second, while the newly charged one is made the 
last of the series. The process is thus kept on 

Fig. 9. 

a. Charging pipe. 
Z>. Steam pipe. 

c. Steam drip. 

d. CO 2 enters. 

/. Discharge pipe. 

A. Agitator, made of iron rods. 

C. Tank in which the precipitate settles. 

B. Baratte body. 

D. Steam jacket. 


continuously. The apparatus used is shown in 
Fig. 9. 

Each baratte holds about 1200 litres of solution, 
and the complete precipitation of all the alumina 
in it takes five to six hours. A mechanical agi- 
tator stirs the contents continually, and a current 
of steam is let into the double bottom so as to 
keep the temperature of the solution about 70. 
The precipitated alumina and the solution of 
Ka 2 C0 3 which remains are received in a vat 
placed beneath each baratte. The solution is de- 
canted off* clear, after standing, and then evapo- 
rated down to dry ness, regenerating the Na*C0 3 
used in treating the beauxite to make the alumi- 
nate, less the inevitable losses inseparable from all 
industrial operations. The deposit of alumina is 
put into a conical strainer to drain, or else into a 
centrifugal drying machine, which rapidly drives 
out of the hydrated alumina the solution of Ka 2 C0 3 
which impregnates it ; a washing with pure w r ater 
in the drier itself terminates the preparation of the 
alumina. At the works at Salindres, a part of this 
alumina is converted into sulphate of alumina, 
which is sold, the remainder being used for the 
aluminium manufacture. After washing in the 
dryer, the alumina presents this composition: 

APO 3 47.5 

H*0 50.0 



III. Preparation of the APCP.ZNaCl. 

When a current of chlorine is passed through a 
mixture of anhydrous alumina and carbon, APC1 6 
is obtained. This simple chloride may be em- 
ployed for obtaining aluminium ; it was first so 
employed by Deville ; but it is deliquescent, its 
preservation is difficult, and its employment very 
inconvenient. Industrially, as indicated by De- 
ville, the double chloride is always used, as it does 
not present these inconveniences to so large a 
degree. The double chloride may be obtained in 
the same manner as the simple chloride ; it is suf- 
ficient to put some common salt, NaCl, into a 
mixture of alumina and carbon, and, on heating 
this mixture strongly, there is formed, by the 
action of the chlorine, Al 2 Cl 6 .2NaCl, which distils 
at a red heat and condenses in a crystalline mass at 
about 200. The Irydrated alumina obtained in 
the preceding operation is mixed with salt and 
finely pulverized charcoal, in proper proportions, 
the whole is sifted, and a mixture produced as 
homogeneous as possible ; then it is agglomerated 
with water and made into balls the size of the fist. 
These balls are first dried in a drying stove, at 
about 150, then calcined at redness in retorts, 
where the double chloride should commence to be 
produced just as the balls are completely dried. 
These retorts are vertical cylinders of refractory 
earth, each one is furnished with a tube in its lower 



part for the introduction of chlorine, and with 
another towards its upper end for the exit of the 
vapor of double chloride. (See Fig. 10.) A lid 

Fig. 10. 

carefully luted during the operation with a mix- 
ture of fine clay and- horse dung serves for the 
charging and discharging of the retort. The 
double chloride is condensed in earthen pots like 
flower pots, made of ordinary clay, and closed by a 
well-luted cover, into which passes a pipe of clay 
to conduct the gas resulting from the operation 
into flues connected with the main chimney. Each 
retort is heated by a fire, the flame of which circu- 
lates all round it, and permits keeping it at a bright 
red heat. An operation is conducted as follows : 


The retort is filled with stove-dried balls, the lid- 
is carefully luted, and the retort is heated gently 
till all the moisture is driven off. This complete 
desiccation is of great importance, and requires 
much time. Then chlorine, furnished by a battery 
of three generating vessels, is passed in. During 
the first hours, the gas is totally absorbed by the 
balls, and the double chloride distils regularly for 
about three hours, and runs into the earthen pots 
where it solidifies. Toward the end, the distilla- 
tion is more difficult and less regular, and the 
chlorine is then only incompletely absorbed. After 
each operation there remains a little residue in the 
retort, which accumulates and is removed every 
two days, when two operations are made per day. 
One operation lasts at least twelve hours, and a 
retort lasts sometimes a month. The double 
chloride is kept in the pots in which it was con- 
densed until the time it is to be used in the next 
operation ; it is almost chemically pure, save traces 
of iron, and is easy to keep and handle. 

IV. Reduction of the Double Chloride by Sodium. 

The difficulty of this operation, at least from an 
industrial point of view, is to get a slag fusible 
enough and light enough to let the reduced metal 
easily sink through it and unite. This result has 
been reached by using cryolite, a white or grayish 
mineral originally from Greenland, very easy to 



melt, formula Al 2 F 6 .6XaF. This material forms 
with the XaCl resulting from the reaction a very 
fusible slag, in the midst of which the aluminium 
collects well, and falls to the bottom. In one ope- 

ration the charge is 

100 kilos 
45 " 
35 u 



The double chloride and cryolite are pulverized, 
the sodium, cut into small pieces a little larger than 
the thumb, is divided into three equal parts, each 
part being put into a sheet-iron basket. The mixture 
of double chloride and cryolite, being pulverized, is 
divided into four equal parts, three of these are 
respectively put in each basket with the sodium, 

Fig. 11. 

the fourth being placed in a basket by itself. The 
reduction furnace (see Fig. 11) is a little furnace of 



refractory brick, with an inclined hearth and a 
vaulted roof. This furnace is strongly braced by 
iron tie-rods, because of the concussions caused by 
the reaction. The flame may at any given moment 
be directed into a flue outside of the hearth. At 
the back part of the furnace, that is to say, on that 
side towards which the bed slopes, is a little brick 
wall which is built up for each reduction and is 
taken away in operating the running out of the 
metal and slag. A gutter of cast iron is placed 
immediately in front of the wall to facilitate run- 
ning out the materials. All this side of the furnace 


ought to be opened or closed at pleasure by means 
of a damper. Lastly, there is an opening for charg- 
ing in the roof, closed by a lid. At the time of an 
operation the furnace should be heated to low red- 
ness, then are introduced in rapid succession the 
contents of the three baske'ts containing sodium, 
etc., and lastly the fourth containing only double 
chloride and no sodium. Then all the openings of 
the furnace are closed, and a very vivid reaction 
accompanied b3 T dull concussions immediately takes 
place. At the end of fifteen minutes, the reaction 
subsides, the dampers are opened, and the heat con- 
tinued, meanwhile stirring the mass from time to 
time with an iron poker. At the end of three 
hours the reduction is ended, and the metal collects 
at the bottom of the liquid bath. Then the run- 
ning out is proceeded with in three phases : First. 
Running off the upper part of the bath, which 


consists of a fluid material completely free from re- 
duced aluminium and constituting the white slag. 
To run this out a brick is taken away from the 
upper course of the little wall which terminates 
the hearth. These slags are received in an iron 
wagon. Second. Running out the aluminium. 
This is done by opening a small orifice left in the 
bottom of the brick wall, which was temporarily 
plugged up. The liquid metal is received in a cast- 
iron melting pot, the bottom of which has been 
previously heated to redness. This aluminium is 
immediately cast in a series of small rectangular 
cast-iron moulds. Third. Running out of the rest 
of the bath, which constitutes the gray slags. 
These were, like the white slags, formed by the 
XaCl and cryolite, but they contain in addition, 
isolated globules of aluminium. To run these out 
all the bricks of the little wall are taken away. 
This slag is received in the same melting-pot into 
which the aluminium was run, the latter having 
been already moulded Here it cools gradually, 
and after cooling there are always found at the 
bottom of the pot several grains of metal. In a 
good operation there are taken from one casting 
10.5 kilos of aluminium, which is sold directly as 
commercial metal. 

The foregoing description from Fremy sets forth 
in its perfection the production of aluminium by 
means of sodium, and until very recently this was 
the only successful commercial process. A large 


amount of aluminium is now produced by this 
process, and it, therefore, does not lack interest. 
The following data as to the expense of this pro- 
cess may he very appropriately inserted here, giving 
the cost at Salindres in 1872. 

In 1872, 3600 kilos of Al were made at Salindres 
at the following average cost: 

a. Manufacture of one kilo of N"a. 

Soda . . . 9.35 kilos (a) 32 fr. per 100 kilos = 3 fr. 9 cent. 

Coal ... 74.32 " "1.40" " " " = 1" 4 " 

Wages ... 1 " 73 " 
Expenses . . 3 " 46 " 

Total . . . . 11 " 32 " 

p. Manufacture of one kilo of Al 2 Cl 6 .2NaCl. 

Anhydrous A1 2 O 3 

0.59 kilos @ 86 fr. per 100 kilos = fr. 50.7 cent. 

MnO 2 . 3.74 " " 14 " " " " =0 " 52.3 " 

HC1 . . 15.72 " " 3 " " " " =0 "47.1 " 

Coal . . 25.78 " "1.40 " " " =0 "36.1 " 

Wages . . . " 23.8 " 

Expenses . . " 38.0 " 

Total .... 2 " 48.0 ' 

y. Manufacture of one kilo of Al. 
Na . .3.44 kilos @ 11.32 fr. per kilo = 38 fr. 90 cent. 
Al 2 Cl 6 .2NaCl 

10.04 " " 2.48" " " =24 " 90 " 

Cryolite 3 87 " " 61.0 " " 100 kilos = 2 " 36 " 

Coal 29.17 " " 1.4.0 " " " " = " 41 " 

Wages ... 1 " 80 " 

Costs . " 88 " 

Total . 69 " 25 

* A. Wurtz, Wagner's Jaresb., 1874, vol. xxi. 


This must be increased ten per cent, for losses 
and other expenses, making the cost of aluminium 
80 fr. per kilo, and it is sold for 100. 

According to a statement in the ' Bull, de la Soc. 
de I'lndustrie Minerale,' ii., 451, made in 1882. 
Salindres was then the only place in which alu- 
minium was manufactured. 


The later improvements in this process have been 
made principally by Mr. J. Webster, of Birming- 
ham, England, and some are claimed by Frishmuth 
of Philadelphia. We will examine the reports of 
Webster's processes and the claims of Frishmuth. 


Recently the statement* has been current in a 
number of journals that material improvements 
have been made in the manufacture of aluminium at 
the Aluminium Crown Metal Works at Hollywood, 
near Birmingham, England, under the direction of 
Mr. Webster. Mr. Webster describes one of his 
improvements, which is patented,f as follows : 
Three parts of alum are mixed with one part of 
coal pitch, and the mixture heated to 200 or 260. 

* Dingier, 1883, cclix. 86. 
f Austrian Pat. Sept. 28, 1882. 


In about three hours the pasty mass is spread upon 
a stone floor, and after becoming cool is broken in 
pieces. Hydrochloric acid of twenty to twenty- 
five per cent, is poured upon these pieces placed in 
piles which are turned over from time to time. 
When the evolution of sulphuretted hydrogen, 
IPS, has stopped, about five per cent, of charcoal 
powder or lampblack, with enough water to make 
a thick paste, is added. The mass is thoroughly 
broken up and mixed in a mill, and then worked 
into balls of about a pound each. These are bored 
through to facilitate drying, and heated in a dry- 
ing chamber at first to 40, then in a furnace from 
95 up to 150. The balls are then kept for three 
hours at a low red heat in retorts while a mixture 
of two parts steam and one part air is passed 
through, so that the sulphur and carbon are con- 
verted into SO 2 and CO 2 , and thus escape. The 
current of gas carries over some K 2 S0 4 , FeSO 4 , and 
A1 2 3 , and is therefore passed through clay con- 
densers. After these have been driven off the dry 
residue is removed from the retort, again ground 
in a mill to fine powder, which now consists of 
A1 2 C 3 and K 2 30 4 . This powder is treated with 
about seven times its weight of water, then boiled 
in a pan or boiler by means of steam for about one 
hour, then allowed to stand till cool. The solution 
containing the K 2 S0 4 is run off and evaporated to 
dryness, the alumina is washed out and dried. 


The product thus obtained contains 84.1 per cent. 
A1 2 3 . 

The ahove patent is seen to cover only the man- 
ufacture of pure alumina. A later account thus 
describes Mr. Webster's plant and processes. It 
is taken from the Birmingham, England, ' Gazette,' 
and was copied into an American journal* as fol- 
lows : 

" There has been recently patented in most of 
the leading countries of the world an invention of 
great importance. The Aluminium Crown Metal 
Co., at Hollywood, near Birmingham, now claim to 
have perfected an improved process by which they 
produce pure alumina from alum, convert it into 
APC1 6 , and reduce this by sodium. By this pro- 
cess the two common impurities of aluminium, 
silicon and iron, are avoided. The inventor is Mr. 
James Webster, the founder and principal of the 
company. Their works having been erected within 
the last five years, the plant is of the most recent 
date, comprising all the modern improvements in 
calcining furnaces and retorts, sheet-rolling and 
wire-drawing mills, together with the requisite 
casting, fitting, and other shops. 

" On retiring from business some years ago as a 
metal manufacturer, Mr. Webster took up his resi- 
dence at Hollywood, and while nominally engaged 

* Bulletin of the Iron and Steel Association, Philadelphia, 
January 3, 1883. 


in farming carried on the experiments which he 
had commenced as far back as 1851 for the inven- 
tion of an expeditious and inexpensive mode of 
producing aluminium. He designed all the vari- 
ous buildings, appliances, and apparatus necessary 
for the carrying on of experiments, upon which he 
expended upwards of 3000, besides 2000 or 
3000 in procuring patent rights at home and 
abroad. A French syndicate has just oifered him 
25,000 for the patent for France alone, while 
parties in the United States, Belgium, and Ger- 
many are arranging to purchase rights. 

u The invention has only been perfected about 
eighteen months, and the firm have but recently 
begun to place the product on the market, yet such 
is the demand, that though they are now working 
day and night, they cannot execute one-quarter of 
the orders accumulating on their books. By the 
ordinary method of precipitation, 12 tons of alum 
and 6 tons of K 2 C0 3 or Na 2 C0 3 are required to pro- 
duce one ton of alumina, and the whole process 
occupies nine weeks ; whereas, in Mr. Webster's 
plan, no precipitant is used, and a ton can be manu- 
factured in a week with the existing plant. The 
cost of one ton of alumina by the ordinary method 
is upwards of 1000, while it is less than 100 by 
Mr. Webster's process. 

" Mr. Webster's process consists in taking a given 
quantity of alum and pitch, which are finely ground, 
mixed together, and placed in a calcining furnace, 


by which means 38 per cent, of water is driven off, 
leaving the sulphur, potash, and alumina, with 
some ferric oxide. The calcined mixture is then 
put in vertical retorts, and steam and air are forced 
through, which leaves a residue of K 2 and A1 2 3 
only. This is then placed in a vat of warm water 
heated by steam. The caustic potash liquor is then 
run oft' and boiled down, while the residual APO 3 
is collected in sacks and dried. This deposit con- 
tains about 84 per cent. APO 3 , while that obtained 
by the old process of precipitation has only 65 per 
cent. Thus a saving is effected of nine-tenths in 
cost and 19 per cent, more alumina is obtained. 
In addition to this, the whole of the bye products 
are recovered, consisting of KOH,S (which is used 
in making H 2 S0 4 ), and aluminate of iron. From 
these bye products is made a blue dye, which is 
sold for six shillings a pound, and is used in place 
of indigo for dyeing calico and other materials. 
The APC1 6 is reduced by sodium. 

" ' The English Ironmonger' for April, 1886, con- 
tains a long article describing the extensions which 
this company have made, their works having now 
attained a large size, w T hile the number and variety 
of their products, in aluminium and its alloys, as 
ingots, wire, sheet, or worked up in "hundreds ot 
different ways, is truly surprising. They have 
monopolized this business in England, and are very 
enterprising in introducing their manufactures else- 



In the United States the only improvement in 
the sodium process of reducing aluminium is 
contained in the following patent: * 

Win. Frishmuth, of Philadelphia, in his patent 
makes the following claims : 

1. The simultaneous generation of sodium vapor 
and a volatile compound of aluminium in two 
separate vessels or retorts, and mingling the 
vapors thus obtained in a nascent (?) state in a third 
vessel, wherein they react on each other. 

2. The sodium vapor is produced from a mixture 
of a sodium compound and carbon, or some other 
reducing agent ; and the aluminous vapor from 
aluminous material. 

3. The simultaneous generation of sodium vapor 
and vapor of A1 2 C1 6 or A1 2 F 6 ; or of sodium vapor 
and Al 2 Cl 6 .2NaCl. 

4. Converting the aluminous material to a vapor 
by heating it in a retort with NaCl,and subjecting 
it at the same time to chlorine gas; mingling the 
vapor of Al 2 Cl 6 .2Nad thus obtained with vapor 
simultaneously generated from Na 2 C0 3 and carbon. 

* U. S. Pat., 308,152. Nov. 18, 1884. 



H. Niewerth, of Hanover, has patented in the 
United States and other countries the following 
process :* A compound of aluminium, with chlorine 
or fluorine, is hrought by any means into the form 
of vapor, and conducted, strongly heated, into 
contact with a mixture of 62 parts Xa 2 C0 3 , 28 coal 
and 10 chalk, which is also in a highly heated con- 
dition. This mixture disengages sodium, which 

O O ' 

reduces the gaseous chloride or fluoride of alumin- 
ium, the nascent sodium being the reducing agent. 
In place of the above mixture other suitable mix- 
tures which generate sodium may be employed, or 
mixtures may also advantageously be used from 
which potassium is generated. 

Hector von Grousilliers, Springe, Hanover, pat- 
ents the following improvement :f In order to 
avoid the difficulties ordinarily met with in the 
use of Al 2 Cl 6 .2XaCl to obtain aluminium, the 
patentee raises the volatilizing point of APCl 6 by 
performing its reduction, either chemically or 
electrolytically, under pressure in a strong, her- 
metically-closed vessel lined with clay or magnesia 
and provided with a safety valve. 

* Sci. Am. Suppl., Nov. 17, 1883. 
t Eng. Pat., June 29, 1885, No. 7858. 




ACCORDING to Knowles's patent,* aluminium 
chloride, APC1 6 , is reduced by means of potassium 
or sodium cyanide, the APC1 6 , either fused or in 
the form of vapor, being brought in contact with 
either the melted cyanide or its vapor. The 
patent further states the strange fact that pure 
alumina may be added to increase the product. 

Corbelli, of Florence,f patented the following 
method in England : Common clay is freed from 
all foreign particles by washing, then well dried. 
One hundred grammes of it are mixed with six 
times its weight of concentrated sulphuric or 
hydrochloric acid ; then the mixture is put in a 
crucible and heated to 400 or 500. The mass re- 
sulting is mixed with 200 grammes of dry yellow 
prussiate of potash and 150 grammes of N"aCl, and 
this mixture heated in a crucible to whiteness. 

* Sir Francis C. Knowles, Eng. Pat. 1857, No. 1742. 
f Wagner's Jaliresb., 1858. 


After cooling, the reduced aluminium is found in 
the bottom of the crucible as a button. 

According to Deville's experiments, this process 
will not give any results. Watts remarks that 
any metal thus obtained must be very impure, 
consisting chiefly of iron. The patent is dated 
1858, No" 142. 


F. W. Gerhard* decomposes aluminium fluor- 
ide, APF 6 , or Al 2 F 6 .6NaF cryolite by subjecting 
it to hydrogen at a red heat. The aluminium 
compound is placed in a number of shallow dishes 
of glazed earthen ware, each of which is surrounded 
by a number of other dishes containing iron 
tilings. These dishes are placed in an oven pre- 
viously heated to redness, hydrogen gas is then 
admitted, and the heat increased. Aluminium 
then separates, hydrofluoric acid, HF, being 
formed, but immediately taken up by the iron 
filings and thereby prevented from reacting on the 
aluminium. To prevent the pressure of the gas 
from becoming too great, an exit tube is provided, 
which may be opened or closed at pleasure. This 
process, patented in England in 1856, No. 2980, is 
ingenious and was said to yield good results. The 
inventor has, however, returned to the use of the 

* Watts's Dictionary. 


more costly reducing agent, sodium, which would 
seem to imply that the hydrogen method has not 
yet quite fulfilled his expectations. 


Mr. A. L. Fleury,* of Boston, mixes pure 
alumina with gas tar, resin, petroleum, or some 
such substance, making it into a stiff paste which 
may be divided into pellets and dried in an oven. 
They are then placed in a strong retort or tube 
which is lined with a coating of plumbago. In 
this they are exposed to a cherry-red heat. The 
retort must be sufficiently strong to stand a press- 
ure of from 25 to 30 pounds per square inch, and 
be so arranged that by means of a safety valve the 
necessary amount of some hydro-carbon may be 
introduced into the retort among the heated mix- 
ture, and a pressure of 20 to 30 pounds must be 
maintained. The gas is forced in by a force pump, 
By this process the APO 3 is reduced, while the 
metal remains as a spongy mass mixed^vith car- 
bon. This mixture is re-melted with metallic 
zinc, and when the latter has collected the alumin- 
ium, it is driven off by heat. The hydrocarbon 
gas under pressure is the reducing agent. The 
time required for reducing 100 pounds of alumina, 
earth, cryolite, or other compound of aluminium, 

* Chemical News, June, 1869, p. 332. 


should not be more than four hours. When the 
gas can be applied in a previously heated condition 
as well as being strongly compressed, the reduction 
takes place in a still shorter period. 

Xothing is now heard of this process, and it has 
been presumably a failure. It is said that several 
thousand dollars were expended by Mr. Fleury 
and his associates without making a practical 
success of it. We should be glad to hear in the 
future that their sacrifices have not been in vain, 
and that the process still has possibilities in it 
which will some time be realized. 

Petitjean* makes aluminium sulphide, APS 3 , by 
one of Fremy's methods,f or makes a double sul- 
phide of aluminium with potassium or sodium by 
mixing alumina with a little tar or turpentine in 
a carbon lined crucible, heating strongly, and then 
mixing with a powder composed of Ka 2 C0 3 , or 
K 2 C0 3 , and sulphur ; again heating a long time at 
bright redness. The sulphide or double sulphide 
thus made is put in a crucible or retort through 
the bottom of which can be led a stream of carbu- 
retted hydrogen, which separates the aluminium 
from its combination with the sulphur. Alumin- 
ium J can also be reduced from APS 3 by mixing it 
with iron filings or a pulverized rnetal having 

* Kerl and Stohman, Poly. Central Blatt. 1858, 888. 
f See Appendix. 
J See Appendix. 


similar qualities, and melting the mixture. A 
metallic mixture may be used instead of carbu- 
retted hydrogen in the above operation. 


M. Comenge,* of Paris, obtains aluminium from 
its sulphide either by heating it in an atmosphere 
of hydrogen, or by heating it with A1 2 3 or 
A1 2 (S0 4 / in such proportions that sulphur dioxide, 
SO 2 , and aluminium may be the sole products; or 
the sulphide may be decomposed by iron, copper, 
or zinc. The reactions involved would be 

A1 2 S 3 + 3H-H= 2 Al + 3H 2 S. 

A1 2 S 3 + 2 A1 2 3 = 6 Al -f 3S0 2 . 

A1 2 S 3 + Al 2 (S0 4 /= 4A1 + 6S0 2 . 

A 2 1S 3 + 3(Fe.Cu.Zn.)= 2A1 + 3(Fe.Cu.Zn.)S. 
Johnsonf patented the following process: Alu- 
minium sulphide is mixed with quite dry A1 2 (S0 4 ) 3 
in such proportions that the sulphur and oxygen 
present may evolve as SO 2 . The mixture is heated 
to redness in an unoxidizing atmosphere, when 
SO 2 evolves and the metal remains. The reaction 
is furthered by agitation. The aluminium in the 
resulting mass can be treated in the way commonly 
used in puddling spongy iron, and then either 
pressed or hammered together. Or, the aluminium 

* Eng. Pat. 1858, No. 461. 

Kerl and S tollman's Handbucb. 


sulphide may be heated to redness in an unoxidiz- 
ing atmosphere and dry hydrogen or water gas 
conducted over it, and the metal separated from 
the resulting mass by dressing. 

Mr. Niewerth's* process may be operated in his 
newly invented furnace, but it may also be carried 
on in a crucible or another form of furnace. The 
furnace alluded to consists of three shaft furnaces, 
the outer ones well closed on top by iron covers, 
and connected beneath by tubes with the bottom 
of the middle one : the tubes being provided with 
closing valves. These side shafts are simply water- 
gas furnaces, delivering hot water-gas to the 
central shaft, and by working the two alternately 
supplying it with a continuous blast. The two pro- 
ducers are first blown very hot by running a blast 
of air through them with their tops open, then the 
cover of one is closed, the blast shut oft', steam 
turned on just under the cover, and water gas 
immediately passes from the tube at the bottom of 
the furnace into the central shaft. The middle 
shaft has meanwhile been filled with these three 
mixtures in their proper order: 

First. A mixture of sodium carbonate, carbon, 
sulphur, and alumina. 

Second. Aluminium sulphate. 

Third. A flux, preferably a mixture of XaCl and 

* Sci. Am. Suppl., Nov. 17, 1885. 


This central shaft must be already strongly 
heated to commence the operation, it is best to fill 
it with coke before charging, and as soon as that 
is hot to put the charges in on the coke. Coke 
may also be mixed with the charges, but it is not 
necessary. The process then continues as follows: 
The water-gas enters the bottom of the shaft at a 
very high temperature. These highly heated 
gases, carbonic oxide and hydrogen, act upon the 
charges so that the first breaks up into a combina- 
tion of sodium sulphide and aluminium sulphide, 
from which, by means of the second charge of 
A1 2 (SG 4 ) 3 , free aluminium is reduced. As the latter 
passes down the shaft, it is melted and the flux 
assists in collecting it, but is not absolutely neces- 
sary. Instead, of producing this double sulphide, 
pure aluminium sulphide might be used for the 
first charge, or a mixture which would generate 
APS 3 ; or, again, pure iui 2 S, K 2 S, CuS, or any 
other metallic sulphide which will produce the 
effect alone, in which case aluminium is obtained 
alloyed with the metal of the sulphide. Instead 
of the first charge a mixture of alumina, sulphur, 
and carbon might be introduced. Or, the A1 2 (S0 4 ) 3 
of the second charge might be replaced by alumina. 
So, one charge may be Na 2 S, K 2 S, or any other 
metallic sulphide, and the second charge may be 
either A1 2 3 or A1 2 (S0 4 ) 3 . 



J. Morris' 55 ' of Uddington claims to obtain alumin- 
ium by treating an intimate mixture of alumina 
and charcoal with carbon dioxide. For this pur- 
pose, a solution of A1 2 C1 6 is mixed with powdered 
wood-charcoal or lampblack, then evaporated till 
it forms a viscous mass which is shaped into balls. 
During the evaporation hydrochloric acid is given 
off. The residue consists of alumina intimately 
mixed with carbon. The balls are dried, then 
treated with steam in appropriate vessels for the 
purpose of driving off all the chlorine, care being 
taken to keep the temperature so high that the 
steam is not condensed. The temperature is then 
raised so that the tubes are at a low red heat, and dry 
carbon dioxide,C0 2 ,is then passed through. This CO 2 
is said to be reduced by the carbon to carbonic oxide, 
CO, which now, as affirmed by Mr. Morris, reduces 
the alumina. Although the quantity of carbonic 
oxide escaping is in general a good indication of the 
progress of the reduction, it is, nevertheless, not 
advisable to continue heating the tubes or vessels 
until the evolution of this gas has ceased, as in con- 
sequence of slight differences in the consistency of 
the balls some of them give up all their carbon 
sooner than others. The treatment with carbon 

* Dingier, 1883, vol. 259, p. 86. German Pat. No. 221oO, 
Aug. 30, 1882. 


dioxide lasts about thirty hours when the substances 
are mixed in the proportion of five parts carbon 
to four parts alumina. Morris states further that 
the metal appears as a porous spongy mass, and is 
freed from the residual alumina and particles of 
charcoal either by smelting it, technically " burn- 
ing it out," with cryolite as a flux or by mechani- 
cal treatment. 



About the first attempt of this nature we can 
find record of is the following article by M. Cha- 
pelle : * 

" When I heard of the experiments of Deville, 
I desired to repeat them, but having neither alu- 
minium chloride nor sodium to use, I operated as 
follows : I put natural clay, pulverized and mixed 
with ground Nad and charcoal, into an ordinary 
earthen crucible and heated it in a reverberatory 
furnace, with coke for fuel. I was not able to get 
a white heat. After cooling, the crucible was 
broken, and gave a dry pulverulent scoria in which 
were disseminated a considerable quantity of small 
globules about one^half a millimetre in diameter, 
and as white as silver, They were malleable, in- 
soluble in nitric or cold hydrochloric acids, but at 
60 dissolved rapidly in the latter with evolution 
of hydrogen ; the solution was colorless and gave 

* Compt. Bendus, 1854, yol, xxxyiij. p. 358. 


with ammonia a gelatinous precipitate of hydrated 
alumina. My numerous occupations do not permit 
me to assure myself of the purity of the metal. 
Moreover, the experiment was made under condi- 
tions which leave much to be desired, but my in- 
tention is to continue my experiments and especially 
to operate at a higher temperature. In addressing 
this note to the Academy I but desire to call the 
attention of chemists to a process which is very 
simple and susceptible of being improved. I hope 
before many days to be able to exhibit larger glob- 
ules than those which my first experiment fur- 

M. Chapelle never did address any further com- 
munications to the Academy on this subject, and 
we must presume that further experiments did not 
confirm these first ones. 

G. W. Keinar* states that the pyrophorous mass 
which results from igniting potash or soda alum 
with carbon, contains a carboniferous alloy of alu- 
minium with potassium or sodium, from which the 
alkaline metal can be removed by weak nitric acid. 


This process, which reduces alumina by carbon 
in the presence of another metal to take up the 
aluminium, using the electric furnace, is the nov- 

* Wagner's Jaliresb. 1859, p. 4. 


elty which is attracting widespread attention to the 
metallurgy of aluminium. Its history has already 
been sketched, and will be still further developed 
in the following pages. It properly comes under 
the heading of " Reduction by Carbon." 

" Early in the present century, Sir H. Davy, 
Berzelius, and Oerstedt, all famous chemists, at- 
tempted unsuccessfully to reduce alumina by elec- 
tricity. Likewise, many learned scientists have 
striven to decompose it by carbon, as other metals 
are smelted from their ores, but without success, 
and the opinion has become profound and wide- 
spread among chemists that alumina could not be 
reduced by carbon and heat. But this is exactly 
what the Cowles process accomplishes, and by its 
means the Cowles Electric Smelting and Alumin- 
ium Company is enabled to supply the alloys of 
aluminium with other metals at one-quarter to one- 
third their former price. * As to the details of the 
process, we refer to the papers of Professor Hunt 
and the one read by Mr. Mabery."* 

The following is the patent claim of Messrs. 
Cowles : U. S. Pat. 324,658 and 324,659, August 
18, 1885. Electric smelting of aluminium. To 
Cowles Bros., Cleveland, Ohio. Claim: Reducing 
the aluminium compound in company with a metal 
in a furnace heated by electricity in presence of 

* Cowles Bros. ' Pamphlet. 


carbon. The alloy of aluminium and the metal 
formed is treated to separate the aluminium. 

The following paper is the first official and sci- 
entific account of Cowles Bros/ process, and was 
read before the American Association for the Ad- 
vancement of Science by Professor Charles F. Ma- 
bery of the Case School of Applied Science, Cleve- 

" The application of electricity to metallurgical 
processes has hitherto been confined to the reduc- 
tion of metals from solution, while few attempts 
have been made to effect dry reductions by means 
of an electric current. Some time since Eugene H. 
Cowles and Alfred H. Cowles, of Cleveland, con- 
ceived the idea of obtaining a continuous high 
temperature on an extended scale by introducing 
into the path of an electric current some material 
that would afford the requisite resistance, thereby 
producing a corresponding increase in the tempera- 
ture. After numerous experiments, coarsely pul- 
verized carbon was selected as the best means for 
maintaining an invariable resistance, and at the 
same time as the most available substance for the 
reduction of oxides. When this material mixed 
with the oxide to be reduced was made a part of 
the electric circuit, enclosed in a fire-clay retort, 
and subjected to the action of a current from a 
powerful dynamo, not only was the oxide reduced, 

* Ann Arbor Meeting, August 28, 1885. 


but the temperature increased to such an extent 
that the whole interior of the retort fused com- 
pletely. In "other experiments lumps of lime, 
sand, and corundum were fused, with a reduction 
of the corresponding metal ; on cooling, the lime 
formed large, well-defined crystals, the corundum 
beautiful red-green and blue octahedral crystals. 
Following up these results with the assistance of 
Prof. Mabery, who became interested at this stage, 
it was soon found that the intense heat thus pro- 
duced could be utilized for the reduction of oxides 
in large quantities,, and experiments were next 
tried on a large scale with the current from a fifty 
horse-power dynamo. For the protection of the 
walls of the furnace, which were of fire-brick, a 
mixture of ore and coarsely pulverized gas carbon 
was made a central core, and was surrounded on 
the side and bottom by fine charcoal, the current 
following the lesser resistance of the core from 
carbon electrodes inserted in the ends of the fur- 
nace in contact with the core. The furnace was 
charged by first filling it with charcoal, making a 
trough in the centre, and filling this with the ore 
mixture, the whole being covered with a layer of 
coarse charcoal. The furnace was closed on top 
with fire-brick slabs containing two or three holes 
for the escape of the gaseous products of the reduc- 
tion, and the whole furnace was made air tight by 
luting with fire clay. Within a few minutes after 
starting the dynamo, a stream of carbonic oxide 


issued through the openings, burning usually with 
a flame eighteen inches high. The time required 
for complete reduction was ordinarily about an 
hour. Experience has already shown that alu- 
minium, silicon, boron, manganese, sodium, and 
potassium can be reduced from their oxides with 
ease. In fact, there is no oxide that can withstand 
the temperature attainable. in this furnace. Char- 
coal is changed to graphite ; does this indicate 
fusion ? As to w r hat can be accomplished by con- 
verting enormous electrical energy into heat within 
narrow limits it can only be said that it opens the 
way into an extensive field of pure and applied 
chemistry. It' is not difficult to conceive of 
temperature limited only by the power of carbon 
to resist fusion. 

" Since the motive power is the chief expense in 
accomplishing reductions by this method, its 
commercial success is closely connected with ob- 
taining power cheaply. Realizing the importance 
of this point, Messrs. Cowles have purchased at 
Lockport, !N". Y., a water-power where they can 
utilize 1200 horse-power. An important feature 
in the use of these furnaces from a commercial 
standpoint is the slight technical skill required in 
their manipulation. The four furnaces operated 
in the experimental laboratory at Cleveland are in 
charge of two young men, who six months ago 
knew absolutely nothing of electricity. The pro- 
ducts at present manufactured are the various 



grades of aluminium bronze^ made from a rich 
furnace product obtained by adding copper to the 
charge of ore. Aluminium silver is also made ; 
and a boron bronze may be prepared by the re- 
duction of boracic acid in contact with copper, 
while silicon bronze is made by reducing silica in 
contact with copper. As commercial results may 
be mentioned the production in the experimental 
laboratory, which averages 50 pounds of 10 per 
cent, aluminium bronze daily, which can be sup- 
plied to the trade in large quantities on the basis 
of $5 per pound for the aluminium contained, the 
lowest market quotation of aluminium being now 
$15 per pound." 

Dr. T. Sterry Hunt has written and read several 
papers on this furnace and process, and we extract 
from them anything not mentioned in Prof. Ma- 
be ry's paper. 

The following paper was read before the Am. 
Ins. of Mining Engineers by Dr. T. Sterry Hunt, 
of Montreal : * 

" The application of electricity in the extraction 
of metals has hitherto been chiefly confined to the 
electrolysis of dissolved or fused compounds by 
various methods. The power of electric currents 
to generate intense heat in their passage through 
a resisting medium has long been known, and the 
late Sir Wm. Siemens thereby succeeded in melting 

* Halifax Meeting, Sept, 1C, 1885. 


considerable quantities of steel. Messrs. Cowles took 
a new step in the metallurgic art by making the 
heat thus produced a means of reducing, in presence 
of carbon, the oxides not only of the alkali metals, 
but of calcium, magnesium, manganese, aluminium, 
silicon, and boron, with an ease which permits the 
production of these elements and their alloys with 
copper and other metals on a commercial scale. 

" If alumina, in the form of granular corundum, 
is mixed with the carbon in the electric path, 
aluminium is rapidly liberated, being in part car- 
ried off with the escaping gas and in part con- 
densed in the upper layer of charcoal. In this way 
are obtained considerable masses of nearly pure 
aluminium, and others of a crystalline compound 
of the metal with carbon. When, however, some 
granular copper is placed with the corundum, an 
alloy of aluminium and copper is obtained, which 
is probably formed in the overlying stratum, but 
at the close of the operation is found in fused 
masses below. In this way there is obtained, after 
the current has passed an hour and a half through 
the furnace, four or tive pounds of an alloy con- 
taining 15 to 20 per cent, of aluminium and free 
from iron. On substituting this alloy for the 
copper in a second operation, an alloy with over 
30 per cent, aluminium is obtained. The diffi- 
culties in the way of gathering together the reduced 
metal without the aid of copper promise to be 
overcome at an early day, so that we may expect 


a cheap production of such alloys and of the pure 
metal. The present plant at Cleveland is but an 
experimental one, and has been in operation only 
a few months. The company will soon put in 
operation at Loekport a 125 horse-power dynamo, 
and nine more of equal power will be added, per- 
mitting the establishment of the electric furnace 
on a large scale," 

Paper read before the National Academy of 
Science by Dr. Hunt: * 

u Dr. Hunt showed some alloys of aluminium 
with carbon and silicon, and a peculiar alloy be- 
lieved to consist entirely of aluminium and nitro- 
gen. As yet, the pure metal has only been 
produced direct from the furnace in small lumps, 
but it may be obtained by melting an alloy of 
aluminium and tin with lead, when the latter 
takes up the tin and separates from the aluminium, 
sinking beneath it. Or, we get aluminium by sub- 
liming either its alloy with carbon or with copper, 
when the pure aluminium is carried over. The 
maximum amount of aluminium which copper can 
tolerate is 10 per cent., until we approach the 
other end of the scale, when alloys with 70 to 80 
per cent, of aluminium, or more, give valuable work- 
able alloys. In the early experiments with the 
Cowles furnace, an engine of 30 horse-power running 
a dynamo yielded a daily output of 50 pounds of 

* Washington Meeting, April 30, 1886. 


10 per cent, aluminium bronze. Brush has now 
constructed an engine running 900 revolutions per 
minute, which for every 35 horse-power developed 
reduces one pound of the alloy per hour. The 
expense of working is now covered by one-half 
cent per horse-power per hour; thus the cost of 
the alloy is about 17 cents per pound. Within the 
past week, the gases given off by the furnace have 
been analyzed. In the first part of the process it 
is found that a large amount of nitrogen is given 
off, showing that air leaks into the furnace. After 
an hour and a half this gas is much diminished. 
The Cowles at first used moist carbon for packing, 
but have now overcome the necessity of dampen- 
ing it, thereby saving the waste of heat in driving 
out the water." 

The latest and most complete description of the 
process is a paper read by Mr. W. P. Thompson 
before the Liverpool Section of the Society of 
Chemical Industry.* Mr. Thompson has been 
Cowles Bros.' agent in taking out their patents in 
England. The paper is as follows : 

" That this invention is a new departure will be 
acknowledged by every one when they learn that 
chromium, titanium, silicon, aluminium, calcium, 
and the other alkaline earth metals are obtained 
by direct reduction of their oxides by carbon till 

* Jrnl. of the Soc. of Chcm. Industry, April 29, 1886. 


a year ago almost universally considered a prac- 
tical impossibility. 

"Conduction of the current of the large dynamo 
to the furnace and hack is accomplished by a com- 
plete metallic circuit, except where it is broken by 
the interposition of the carbon electrodes and the 
mass of pulverized carbon in which the reduction 
takes place. The circuit is of 13 copper wires, 
each 0.3 inch in diameter. There is likewise in 
the circuit an ampere meter, or ammeter, through 
whose helix the whole current flows, indicating 
the total strength of the current heing used^Cfhis 
is an important element in the management of the 
furnace, for, hy the position of the finger on the 
dial, the furnace attendant can tell to a nicety 
what is being done hy the current in the furnace. 
Between the ammeter and the furnace is a resist- 
ance coil of German silver kept in water, throwing 
-more or less resistance into the circuit as desired. 
This is a safety appliance used in changing the 
current from one furnace to another, or to choke 
off the current before breaking it by a switch. 

"The furnace (see Figs. 12, 13, 14) is simply a 
rectangular box, A, one foot wide, five feet long 
inside, and fifteen inches deep, made of firebrick. 
From the opposite ends through the pipes BB the 
two electrodes CC pass. The electrodes are im- 
mense electric-light carbons three inches in diam- 
eter and thirty inches long. If larger electrodes 
are required, a series this size must be used 


Fig 12. [( UNIVERSITY 

Longitudinal section. 
Fig. 14. 

Transverse section. 

instead, as so far all attempts to make larger car- 
bons that will not disintegrate on becoming 


incandescent have failed. The ends of the carbons 
are placed within a few inches of each other in the 
middle of the furnace, and the resistance coil and 
ammeter are placed in the circuit. The ammeter 
registers 50 to 2000 amperes. These connections 
made, the furnace is ready for charging. 

"The walls of the furnace must first be pro- 
tected, or the intense heat would melt the fire 
brick. The question arose, what would be the 
best substance to line thewalls? Finely powdered 
charcoal is a poor conductor of electricity, is con- 
sidered infusible and the best non-conductor of 
heat of all solids. From these properties it would 
seem the best material. As long as air is excluded 
it will not burn. But it is found that after 
usin^ pure charcoal a few times it becomes value- 
less ; it retains its woody structure, as is shown in 
larger pieces, but is changed to graphite, a good 
conductor of electricity, and thereby tends to 
diffuse the current through the lining, heating it 
and the walls. The fine charcoal is therefore 
washed in a solution of lime-water, and after dry- 
ing, each particle is insulated by a fine coating of 
lime. The bottom of the furnace is now filled 
with this lining about two or three inches deep. 
A sheet-iron gauge is then placed along the sides 
of the electrodes, leaving about two inches between 
them and the side walls, in which space more of 
the charcoal is placed*. The charge J5/, consisting 
of about 25 pounds of alumina, in its native form as 


corundum, 12 pounds of charcoal and carbon, and 
50 pounds of granulated copper, is now placed 
within the gauge and spread around the electrodes 
to within a foot of each end of the furnace. In 
place of granulated copper, a series of short copper 
wires or bars can be placed parallel to each other 
and transverse to the furnace, among the alumina 
and carbon, it being found that where grains are 
used they sometimes fuse together in such a way 
as to short-circuit the current. After this, a bed 
of charcoal, -F, the granules of which vary in size 
from a chestnut to a hickory, is spread over all, 
and the gauge drawn out. This coarse bed of 
charcoal above the charge allows free escape of the 
carbonic oxide generated in the reduction. The 
charge being in place, an iron top, 6r, lined with 
h're-brick, is placed over the whole furnace and 
the crevices luted to prevent access of air. The 
brick of the walls insulate the cover from the 

" Xow that the furnace is charged and the cover 
luted down, it is started. The ends of the electrodes 
were in the beginning placed close together, as 
shown in the longitudinal section, and for this 
cause the internal resistance of the furnace may be 
too low for the dynamo, and cause a short circuit. 
The operator, therefore, puts sufficient resistance 
into the circuit, and by watching the ammeter and 
now and then moving one of tfie electrodes out a trifle, 
he can prevent undue short circuiting in the begin- 


ning of the operation. In about ten minutes, the 
copper between the electrodes has been melted and 
the latter are moved far enough apart so that the 
current becomes steady. The current is now in- 
creased till 1300 amperes are going through, 
driven by 50 volts. Carbonic oxide has already 
commenced to escape through the two orifices in 
the top, where it burns with a white flame. By 
slight movements outwards of the electrodes during 
the coming five hours, the internal resistance in 
the furnace is kept constant, and at the same time 
all the different parts of the charge are brought in 
turn into the zone of reduction. At the close of 
the run the electrodes are in the position shown in 
the plan, the furnace is shut down by placing a 
resistance in the circuit and then the current is 
switched into another furnace charged in a similar 
manner. It is found that the product is larger if 
the carbons are inclined at angles of 30 to the 
horizontal plane. 

" This regulating of the furnace by hand is rather 
costly and unsatisfactory. Several experiments 
have therefore been tried to make it self-regulating, 

O O ' 

and on January 26, 1886, a British patent was 
applied for by Cowles Bros., covering an arrange- 
ment for operating the electrodes by means of a 
shunt circuit, electro-magnet, and vibrating arma- 
ture. Moreover, if the electrodes were drawn back 
and exposed to the air in their highly heated state, 
they would be rapidly wasted away. To obviate 


this, Messrs. Cowles place what may be called a 
stuffing box around them, consisting of a copper 
box tilled with copper shot. The wires are attached 
to the boxes instead of the electrodes. The hot 
electrodes as they emerge from the furnace first 
encounter the shot, which rapidly carry off the 
heat, and by the time they emerge from the box 
they are too cool to be oxidized by contact with 
the air. 

u Xinety horse-power have been pumped into 
the furnace for five hours. At the beginning of 
the operation the copper first melted in the centre 
of the furnace. There was no escape for the heat 
continually generated, and the temperature in- 
creased until the refractory corundum melted, and 
being surrounded on all sides by carbon gave up its 
oxygen. This oxygen, uniting with the carbon to 
form carbonic oxide, has generated heat which 
certainly aids in the process. The copper has had 
nothing to do with the reaction, as it will take 
place in its absence. Whether the reaction is due 
to the intense heat or to electric action it is difficult 
to say. If it be electric, it is Messrs. Cowles's im- 
pression that we have here a case where electrolysis 
can be accomplished by an alternating current, 
although it has not been tried as yet. Were the 
copper absent, the aluminium set free would now 
absorb carbon and become a yellow, crystalline 
carbide of aluminium ; but, instead of that, the 
copper has become a boiling, seething mass, and 


the bubblings of its vapors may distinctly be heard. 
The vapors probably rise an inch or two, condense 
and fall back, carrying with them the freed alumin- 
ium. This continues till the current is taken otf 
the furnace, when we have the copper charged 
with 15 to 30 per cent., and in some cases as high 
as 40 per cent, of its weight of aluminium, and a 
little silicon. After cooling the furnace this rich 
alloy is removed. A valuable property of the fine 
charcoal is that the metal does not spread and run 
through its interstices, but remains as a liquid mass 
surrounded below arid on the sides by fine charcoal 
which sustains it just as flour or other fine dust 
will sustain drops of water for considerable periods, 
without allowing them to sink in. The alloy is 
white and brittle. This metal is then melted in 
an ordinary crucible furnace, poured into large 
ingots, the amount of aluminium in it determined 
by analysis, again melted, and the requisite amount of 
copper added to make the bronze desired. 

"Two runs produce in ten hours' average work 
100 pounds of white metal, from which it is esti- 
mated that Cowles Bros., at Lockport, are producing 
aluminium in its alloys at a cost of about forty cents 
per pound. The Cowles Co. will shortly have 1200 
horse-power furnaces. With a larger furnace there 
is no reason why it should not be made to run con- 
tinuously like the ordinary blast furnace. 

" In place of the copper any non-volatile metal 
may be used as a condenser to unite with any 


metal it may be desired to reduce, provided, of 
course, that the two metals are of such a nature 
that they will unite at this high temperature. In 
this way aluminium may be alloyed with iron, 
nickel-silver, tin, or cobalt. Messrs. Cowles have 
made alloys containing 50 Al and 50 Fe, 30 Al, 
and 70 Cu, 25 Al and 75 ]^i. Silicon or boron 
or other rare metals may be combined in the same 
way, or tertiary alloys may be produced ; as, for 
instance, where tire clay is reduced in presence of 
copper we obtain an alloy of aluminium, silicon, 
and copper. This alloy is white and brittle if it 
contains over ten per cent, of aluminium and sili- 
con together. With from two to six per cent, of 
these two, in equal proportions, the alloy is stronger 
than gun-metal, has great toughness, does not 
oxidize when heated in the air, and has a fine gold 
color. I hear to-day that an aluminium-silicon 
bronze wire made by Cowles has shown a tensile 
strength of 200,000 pounds, hitherto unprecedented 
in any metal. 

"As to the ores of aluminium. For Mitis cats- 
ings, where iron and silicon are not prejudicial, 
beauxite or various clays may be used to advantage. 
For bronze making, alumina containing silica in 
considerable quantities is as available as the pure 
earth and is indeed superior to it." To manufacture 
pure aluminium, pure alumina is necessary. 
Cowles Bros, use corundum obtained from Xorthern 
Georgia. (See p. 49.) 




The statement has been made* that aluminium 
sulphide, APS 3 , is to be obtained from powdered 
cryolite by treating it with water, which dissolves 
out sodium fluoride, NaF, and the residual A1 2 F 6 
being calcined with sulphide of lime, CaS, there 
results A1 2 S 3 and CaF 2 . The A1 2 S 3 is then decom- 
posed by heating to redness with iron turnings. 

According to a patent given to F. Lauterborn,f 
Germany, Aug. 14, 1880, if pulverized cryolite is 
boiled with water, NaF is set free and A1 2 F 6 
remains. Likewise, calcium fluoride, CaF 2 , boiled 
with APC1 6 gives CaCP and APF 6 . The aluminium 
fluoride by heating with sulphide of lime will be 
converted into APS 3 . Finally, the APS 3 , by heat- 
ing red hot with iron gives, it is claimed, metallic 

The above are all the details of this process to 
be found. See in the Appendix an experiment on 
thus decomposing cryolite. 

H. Niewerthij: has patented the following pro- 
cess: "Ferro-silicumis mixed with APF 6 in proper 
proportions and the mixture submitted to a suit- 
able red or melting heat by which the charge is 
decomposed into volatile silicon fluoride, SiF 4 , iron, 
and aluminium, the two latter forming an alloy. 

* Chemical News, 1860. 

t Dingier, 242, p. 70. 

\. Sci. Am. Suppl. Nov. 17, 1883. 


In order to obtain the valuable alloy of aluminium 
and copper from this iron-aluminium alloy, the 
latter is melted with metallic copper, which will 
then by reason of greater affinity unite with the 
aluminium, while the iron will retain but an 
insignificant amount of it. On cooling the bath, 
the bronze and iron separate in such a manner that 
they can readily be kept apart. In place of pure 
APF 6 , cryolite may advantageously be employed, 
or A1 2 C1 6 may also be used, in which case silicon 
chloride volatilizes instead of the fluoride. Or, 
again, pure silicon may be used with APF 6 , cryo- 
lite, or APC1 6 , in which case pure aluminium is 

Preparation of Aluminium and Sodium im the 
Bessemer Converter. 

According to the experiments of Mr. W. P. 
Thompson,* sodium and aluminium may be advan- 
tageously prepared by means of a Bessemer con- 
verter. The same process it seems should serve 
equally well for the preparation of the other 
difficultly reducible metals, such as calcium, stron- 
tium, barium, magnesium, etc. 

Mr. "W. P. Thompsonf has taken out a patent in 
England^ for the manufacture of aluminium and 
similar metals, which is carried out as follows: 
The inventor employs as a reducing agent iron, 

* Bull, de la Soc. Chcm. de Paris, 1880, xxiv. 128. 
f Idem. p. 719. \ Mar. 27, 1879. No. 2101. 


either alone or conjointly with carbon or hydrogen. 
The operation is effected in an apparatus similar to 
a Bessemer converter, divided into two compart- 
ments. In one of these compartments is placed 
melted iron, "or an alloy of iron, which is made to 
run into the second by turning the converter. 
This last compartment has two tuyeres, one of 
which serves to introduce hydrogen, while by the 
other is introduced either A1 2 C1 6 , APF 6 , APC1 6 .- 
2NaCl, or Al 2 F 6 .6NaF, in liquid or gaseous state. 
In presence of the hydrogen the iron takes up 
chlorine or fluorine, chloride or fluoride of iron is 
diseno-ao-ed, and aluminium mixed with carbon 

D O ' 

remains as a residue. Then this mixture of iron, 
aluminium, and carbon is returned to the other 
compartment where the carbon is burnt out by 
means of a current of air. The mass being then 
returned to the chamber of reduction, the operation 
described is repeated. When almost all the iron 
has been consumed, the reduction is terminated by 
hydrogen alone. There is thus obtained an alloy 
of iron and aluminium. (The preparation of sodium 
does not require the intervention of hydrogen. A 
mixture of iron with an excess of carbon and 
caustic soda, N"aOH, is heated in the converter, 
when the sodium distils off.* "When all the 
carbon has been burnt, the iron remaining as a 
residue may be converted into Bessemer steel. As 
iron forms an alloy with potassium, the method 

* Compare with p. 141. 


would scarcely serve for the production of that 
metal.) To obtain the pure aluminium, sodium is 
first prepared by the process indicated, the chlo- 
ride or fluoride of aluminium is introduced into 
the apparatus in the other chamber, when the 
metal is reduced by the vapor of sodium. The 
chambers ought to be slightly inclined, and an 
agitator favors the reaction. The inventor intends 
to apply his process to the manufacture of mag- 
nesium, strontium, calcium, and barium. 

Calvert and Johnson* made experiments on the 
reduction of aluminium by iron, and the produc- 
tion thereby of iron-aluminium alloys. We give 
the report in their own words : 

"We shall not describe all the fruitless efforts 
we made, but confine ourselves only to those which 
gave satisfactory results. The first alloy we ob- 
tained was by heating to a white heat for two 
hours the following mixture : 

8 equivalents of A1 2 C1 6 . . . 1076 parts. 
40 " " iron filings . . 1120 *' 

8 u " lime . . .224 " 

"The lime was added to the mixture with the 
view of removing the chlorine from the APC1 6 , so 
as to liberate the metal and form fusible calcium 
chloride, CaCl 2 . Subtracting the lime from the 
above proportion, we ought to have obtained an 
alloy having the composition of 1 Equivalent Al 

* Phil. Mag., 1855, x. 240. 


to 5 Equivalents of Fe, or with 9.09 per cent, 
aluminium. The alloy we obtained contained 12 
per cent., which leads to the formula AlFe 4 . This 
alloy, it will be noticed, has an analogous com- 
position to the one we made of iron and potas- 
sium, and like it was extremely hard, and rusted 
when exposed to a clamp atmosphere. Still it 
could be forged and welded. We obtained a 
similar alloy by adding to the above mixture some 
very finely pulverized charcoal and subjecting it 
to a high heat in a forge furnace for two hours. 
This alloy gave on analysis 12.09 per cent.* But, in 
the mass of CaCl 2 and carbon remaining in the cruci- 
ble there was a large amount of globules varying 
in size from a pin head to a pea, as white as silver 
and extremely hard, which did not rust in the air 
or in hyponitric fumes. Its analysis gave 24.55 
per cent, aluminium ; the formula APFe 3 would 
give 25 per cent. Therefore this alloy has the 
same composition as A1 2 3 , iron replacing oxygen. 
"We treated these globules with weak sulphuric 
acid, which removed the iron and left the alumin- 
ium, the globules retaining their form, and the 
metal thus obtained had all the properties of the 
pure aluminium. 

"We have made trials with the following mix- 
ture, but, although they have yielded results, still 
they are not sufficiently satisfactory to describe in 

* In the original paper it is given as 12.09 per cent. iron. 
The inference is unavoidable that this was a misprint, but it 
is not corrected in the Errata at the end of the volume. 


this paper, which is the first of a series we intend 
publishing on alloys. This mixture was : 

Kaolin 1750 parts. 

NaCl 12CO " 

Fc 875 " 

" From this we obtained a metallic mass and a 
few globules which we have not yet analyzed." 

Fremy: Alloys of aluminium and iron have 
been prepared by Benzon by calcining a mixture 
of alumina, carbon, and iron or Fe 2 3 . (See p. 214.) 

Watts : E. L. Benzon* reduces aluminium by 
heating alumina with the oxide of another metal, 
as of copper, iron, zinc, or a mixture of alumina 
with carbon and the other metal in a free state, 
the materials being all finely divided and mixed 
in atomic proportions, or rather with the carbon 
slightly in excess. 

M. Evrard,f in order to make aluminium 
bronze, makes use of an aluminous pig iron. (It 
is not stated how this aluminous pig iron is made.) 
This is slowly heated to fusion, and copper is 
added to the melted mass. Aluminium, having 
more affinity for copper than for iron, abandons 
the latter and combines with the copper. After 
the entire mass has been well stirred, it is allowed 
to cool slowly so as to permit the bronze, which 
is heavier than iron, to find its way to the bottom 

* Eng. Pat., 1858, No. 2753. 

t Annalesdu Genie Civil, Mars, 1867, p. 189. 


of the crucible. M. Evrard makes silicon bronze 
in the same way by using siliceous iron. 

< Eng. and Mining Journal,' May 15, 1886 : " The 
iron-aluminium alloy used in the Mitis process, we 
are informed by Mr. Ostberg, is made in Sweden 
by the addition of clays in iron smelting, a patented 
process producing alloys with 7 to 8 per cent, 
aluminium very cheaply. Mr. Ostberg adds that 
he purchased a small quantity of Cowles Bros.' 
alloy, which gave rise to our previous unqualified 
statement that he used Cowles' alloys." (See 
'Mitis Castings,' Part XL). 


Calvert and Johnson* obtained copper alloyed 
with aluminium by recourse to a similar chemical 
reaction to that employed to get their iron-alu- 
minium alloy. Their mixture was composed of 

20 equivalents of Cu . . . . 640 parts. 

8 " " A1 2 C1 6 .... 1076 " 

10 " " CaO . . . . 280 " 

" We mixed these substances intimately together, 
and after having subjected them to a high heat for 
one hour we found at the bottom of the crucible a 
melted mass covered with cuprous chloride, Cu 2 Cl 2 , 
and in this mass small globules, which on analysis 
contained 8.47 per cent, aluminium, corresponding 
to the formula 

* Phil. Mag. 1855, x. 242. 


5 equivalents of Cu . . 160 . . 91.96 per cent. 
1 " " Al . . 14 . . 8.04 " 

174 100.00 

" We made another mixture of A1 2 C1 6 and copper 
in the same proportions as above, but left out the 
lime. We obtained an alloy in this case also, 
which contained 12.82 per cent, aluminium, corres- 
ponding to the formula 

3 equivalents of Cu . . 96 . . 87.27 per cent. 
1 " " Al . . 14 . . 12.73 " 

110 100.00 

Kerl and Stohman give the following account of 
Benzon's process: "Benzon* has patented the 
reduction of aluminium with copper, forming an 
aluminium-copper alloy. He mixes copper, or 
oxidized copper, or cupric oxide, in the finest 
possible state, with fine, powdered, pure alumina 
and charcoal, preferably animal charcoal. The 
alumina arid copper or copper oxide are mixed in 
equivalent proportions, but an excess of charcoal 
is used. The mixture is put in a crucible such as 
is used for melting cast steel, which is lined inside 
with charcoal. The charge is covered with char- 
coal, and the crucible subjected first to a tempera- 
ture near the melting point of copper, until the 
alumina is reduced, and then the heat is raised 
high enough to molt down the alloy. In this way 
can be obtained a succession of alloys, whose hard- 

* Eng. Pat, 1858, No. 27C3. 


ness and other qualities depend on the percentage 
of aluminium in them. In order to obtain alloys 
of a certain composition, it is best to produce first 
an alloy of the highest attainable content of alu- 
minium, to analyze it, and then melt it with the 
required quantity of copper. The same process 
can be used for the reduction of alumina with iron 
or Fe 2 3 , only the carbon must in this case be in 
greater excess, and a stronger heat kept up longer 
must be used than when producing the copper- 
aluminium alloy. In contact with Fe 2 3 the 
alumina is more easily reduced than with metallic 

Kerl and Stohman remark that were these 
methods practicable, then at once there is the 
possibility of producing copper-aluminium alloys 
at a low price, and, on the other hand, of easily 
producing pure aluminium from the iron alloy. 
According to researches conducted in the labora- 
tories at Zurich and Augsburg, it was found that 
the melted-down copper contained either no alu- 
minium or at most a trace. (See Appendix.) 

Aluminium-bronze is also made by Mr. Evrard's 
process given on p. 211. 


M. Dullo* observes that the double chloride of 
aluminium and sodium, which he makes directly 

* Bull, dc la Soc. Chem. 1860, v. 472. 


from clay, may be reduced by zinc. He says, 
" The reduction by zinc presents no difficulties, 
but it is less easy tban with sodium. An excess 
of zinc should be employed, which may be got rid 
of afterwards by distillation. The metal thus pre- 
pared possesses all the characteristics and all the 
properties of that obtained from beauxite with 

M. IS". Basset,* a chemist in Paris, has recently 
patented a new process for obtaining aluminium. 
If the statements are correct they are of great value. 
The paper is as follows: All the metalloids and 
the metals which form by double decomposition 
proto-chlorides or sesqui-chlorides more fusible or 
more soluble than A1 2 C1 6 may reduce A1 2 C1 6 or 
even Al'Cr^NaCl. Thus, As, Bi, Cu, Zn, Sb, Hg, 
or even Sn, or amalgam of Zn, Sb, or Sn may be 
employed to reduce the single or double chloride. 
The author employs zinc in preference to the others 
in consequence of its low price, the facility of its 
employment, its volatility, and the property which 
it has of metallizing easily the aluminium as it is 
set free. When metallic zinc is put in the presence 
of Al 2 Cl 6 .2XaCl at 250 to 300, zinc chloride, 
ZnCl 2 , is formed and aluminium is set free. This 
dissolves in the zinc present in excess, the ZnCl 2 
combines with the I^aCl, and the mass becomes 
little by little pasty, then solid, while the alloy 

* Le Genie Industrie], 1862, p. 152. 


remains fluid. If the heat is now raised, the mass 
melts anew, the zinc reduces a new portion of the 
double chloride, and the excess of zinc enriches 
itself in aluminium proportionately. These facts 
constitute the basis of the following general pro- 
cess : One equivalent of A1 2 C1 6 is melted, two of 
KaCl added, and when the vapors of hydrochloric 
acid are dissipated, four equivalents of zinc, in 
powder or grain, is introduced. The zinc melts 
rapidly, and by agitation the mass of chloride 
thickens and solidifies. The mass is now composed 
of A1 2 C1 6 , NaCl, and ZnCl 2 , and remains in a pasty 
condition on top of the fluid zinc containing alu- 
minium. This pasty mass is removed, piled up in 
a crucible or in a furnace, and bars of the fluid 
alloy of zinc and aluminium obtained from a pre- 
vious operation are placed on top of it. This is 
gradually heated to bright redness, and kept there 
for an hour. The melted mass is then stirred with 
a rake and poured out. It is an alloy of the two 
metals in pretty nearly equal proportions. This 
alloy, melted with some chloride from the first 
operation furnishes aluminium containing only a 
small per cent, of zinc, which disappears by a new 
fusion under chloride mixed with a little A1 2 F 6 , 
providing the temperature is raised to a white 
heat and maintained till the cessation of the vapors 
of zinc, air being excluded. 

The metal is pure if the zinc employed contained 
no foreign materials or metals. It is melted and 


cast into ingots. In case the zinc contains iron, or 
even if the A1*C1 6 contains some, the metallic pro- 
duct of the second operation may be treated with 
dilute sulphuric acid to remove it. The insoluble 
residue is washed and melted layer by layer with 
fluorspar or cryolite and a small quantity of APC1 6 .- 
2$"aCl, intended solely to help the fusion." 

Mr. Wedding* makes the following remarks on 
this process : 

" It is some time since Mr. Basset established the 
possibility of replacing sodium by zinc in the 
manufacture of aluminium. Operating on A1 2 C1 6 .- 
2XaCl with granulated zinc, the reduction takes 
place towards 300. The reduced aluminium dis- 
solves in the excess of zinc, while the ZnCl 2 formed 
combines with the ]S"aCl, forming a pasty mass if 
the heat is not raised. Under the action of heat 
the alloy enriches itself in aluminium, because the 
zinc volatilizes. The zinc retained by this alloy is 
completely eliminated by fusion with Al 2 Cl 6 .2KaCl 
and a little fluorspar. The temperature ought to 
be pushed at last to a white heat, and maintained 
till no vapor of zinc escapes, air being excluded 
during the operation. These results I have con- 
firmed, having submitted the experiments of Mr, 
Basset to an attentive examination, and I recom- 
mend its use. However, the process demands very 
much precaution because of the high temperature 

* Journal de Pharm. L4] iii. p. loo (1866). 


which it necessitates. Another chemist, Mr. 
Spccht, even in 1860 decomposed APC1 6 by zinc, 
and has the same report to make that he thinks 
the process will be some time advantageously prac- 
tised on a large scale." 

However, this method has not succeeded in being 
established in practice, probably on account of the 
high temperature which is necessary to drive off 
the zinc, in which operation some aluminium is 

Kagensbusch,* in Leeds, makes the singular 
proposition to melt clay with fluxes ; then, by add- 
ing zinc or lead, to decompose it by an electrical 
current and isolate an aluminium-zinc or alu- 
minium-lead alloy, from which the zinc may be 
volatilized or the lead cupelled. 

Mr. Fred. J. Seymourf patents the reduction of 
aluminium by zinc, and makes the following claim : 
An improvement in extracting aluminium from 
aluminous earths and ores by mixing them with 
an ore of zinc, carboniferous material and a flux, 
and subjecting the mixture to heat in a closed 
retort, whereby the zinc is liberated, is caused to 
assist in bringing or casting down the aluminium 
in a metallic state, and an alloy of aluminium and 
zinc is obtained. 

The only information outside of the patent claims 

* Eng. Pat., 1872, No. 4811. 

t U. S. Pat., No. 291,631, Jan. 8, 1884. 


which I could find in regard to this process is con- 
tained in the following newspaper article, which, 
although wordy and indefinite, will have to be 
taken in the absence of a more precise account. 

"Mr. F. J. Seymour,* a well-known practical 
metallurgist, late of Bridgeport, Conn., has, as the 
result of several years' study, succeeded in producing 
aluminium at a low cost, and by the novel furnace 
just designed asserts that he can extract the metal 
on a commercial basis in large quantities. Not to 
go into all the technical details, which are ex- 
tremely interesting to metallurgists, it is sufficient 
to say that Mr. Seymour has discovered that the 
close affinity existing between aluminium and zinc 
can be utilized in vaporizing, capturing, and deposit- 
ing the aluminium, the separation being effected 
by the aid of heat in a furnace, or rather a series of 
furnaces, of peculiar construction. The charge for 
each furnace is zinc ore 100 parts, koalin 50, carbon 
(either anthracite coal or its equivalent in hydro- 
carbon gas) 125, pearl ash or its equivalent 15, 
XaCl 10 ; all intimately mixed. The retorts are of 
steel, 36 inches long, 12 inches diameter, sides J 
inch thick. The heat necessary to produce the 
result is about 2500 F., or 1400 C. Properly 
handled, one furnace should make two charges in 
24 to 30 hours. Four men can operate 50 retorts. 

* Cleveland Letter to the ' New York Times,' April 14, 



The number of retorts can be increased to several 
hundred in a single system. Capitalists are already 
interested in this new process, and the prospects are 
that operations on an extensive scale will soon 
follow. Independent investigations in the same 
line in this city have resulted in the recent incor- 
poration of a company for the extraction of alu- 
minium by electricity. Thus far the secret of the 
process has been strictly guarded, and no details 
can be given." 

Mr. Seymour has quite recently taken out another 
patent, the claims of which are hardly reconcilable 
with those of the former patent. The claim is as 
follows : 

Patent to Fred. J. Seymour,* Wolcottville, Conn., 
assignor of one-half to Mr. Henry Brown, New 
York. The following is the claim : u The process 
of extracting aluminium from aluminous earths, 
consisting in subjecting such ore or earth with an 
ore of zinc, carbonaceous matter, and a flux, to 
heat, in a retort; wherein the oxides of aluminium 
and zinc are vaporized ; collecting and condensing 
the vapors in a condenser, and afterwards subject- 
ing the condensed product to heat with carbo- 
naceous matter, substantially as herein described." 

If Mr. Seymour can make a process work accord- 
ing to the details of the above extraordinary claim, 

* U. S. Pat. No. 337,996, filed March, 1885, granted March 
16, 1886. 


he will certainly have a claim on the admiration 
of all scientific men. The idea of vaporizing the 
oxides of zinc and aluminium is certainly unique. 
I wrote to Mr. Seymour, asking for further details 
of his process, and if he was making any alu- 
minium, but have received no further informa- 
tion than has already been given. 

4 The American Machinist,' August, 1886, con- 
tains the statement that the American Aluminium 
Company has been organized at Detroit with a 
capital stock of 2,500,000 ; to use the patents of 
Dr. Smith for the United States, Great Britain and 
France. I was informed- by a gentleman in the 
aluminium industry that this company were to 
operate Mr. Seymour's zinc process. 


Accord ing to the invention of Mr. A. E.Wilde,* of 
Xotting Hill, lead or sulphide of lead, or a mixture 
of the two, is melted and in a molten state poured 
upon dried or burnt alum. The crucible in which 
the mass is contained is then placed in a furnace 
and heated, with suitable fluxes. The metal, when 
poured out of the crucible, will be found to contain 
aluminium. The aluminium and lead can be sub- 
sequently separated from each other by any known 
means, or the alloy or mixture of the two metals 

* Sci. Am. Suppl., Aug. 11, 1877. 


can be employed for the various useful purposes for 
which lead is more or less unsuited. 

Kagensbusch's process, using lead, is described 
on p. 218 under the reduction by zinc. 


"W. Weldon,* of Burstow, Eng., claims to melt 
together cryolite with CaCl 2 or another non-metal- 
lic chloride or sulphide, and then to reduce the 
APC1 6 or APS 3 produced with manganese, which 
he claims is even powerful enough to reduce 


The reduction of A1 2 C1 6 or APCl 6 .2^aCl by 
sodium is the only process by which the pure 
metal is now made. However, many attempts 
have been made to isolate it by means of the elec- 
tric current. The reduction may take place in 
either the dry or wet way. The reduction of 
fused APCl 6 .2XaCl by the battery was accidentally 
discovered simultaneously by Deville in France 
and Bunsen in Germany, in 1854, and is nothing 
else but an application of the process already an- 
nounced by Bunsen of decomposing magnesium 

* Eng. Pat., 1883, No. 97. Wagner's Jahresb., 1884. 


chloride, MgCl 2 , by the battery. Deville's account 
of the process is as follows: * 

"It appears to me impossible to obtain alumin- 
ium by the battery in aqueous solutions. I should 
believe this to be an impossibility if the brilliant 
experiments of Mr. Bunsen in the preparation 
of barium did not shake my convictions. Still 
I must say that all the processes of this de- 
scription which have recently been published for 
the preparation of aluminium have failed to give 
me good results. To prepare the bath for decom- 
position in the dry way, I heated a mixture of 2 
parts APC1 6 and 1 part NaCl, dry and pulverized, 
to about 200 in a porcelain capsule. They com- 
bine with disengagement of heat, and the resulting 
bath is very fluid. The apparatus which I use for 
the decomposition comprises a glazed porcelain 
crucible, which as a precaution is placed inside a 
larger one of clay. The w r hole is covered by a 
porcelain cover pierced by a slit to give. passage to 
a large, thick leaf of platinum, w 7 hich serves as the 
negative electrode ; the lid has also a hole through 
which is introduced, fitting closely, a well-dried 
porous cylinder, the bottom of which is kept at 
some distance from the inside of the porcelain 
crucible. This porous vessel incloses a pencil of 
retort carbon, which serves as the positive electrode. 
Melted Al 2 Cl 6 .22s"aCl is poured into the porous jar 
and into the crucible so as to stand at the same 

* Ann. de CUem. et de Phys. [3J. 46, 452. 



height iu both vessels; the whole is heated just 
enough to keep the bath in fusion, and there is 
passed through it the current from several Bunsen 
cells, two cells being strictly sufficient. The an- 
nexed diagram shows the crucibles in section. 

Fig. 15. 

" The aluminium deposits with some JS"aCl on 
the platinum leaf; the chlorine, with a little 
APC1 6 , is disengaged in the porous jar, and forms 
white fumes, which are prevented from rising by 
throwing into the jar from time to time some dry, 


pulverized XaCl. To collect the aluminium, the 
platinum leaf is removed when sufficiently charged 
with the saline and metallic deposit; after letting 
it cool the deposit is rubbed off and the leaf placed 
in its former position. The material thus detached, 
melted in a porcelain crucible, and after cooling 
washed with water, yields a gray, metallic powder, 
which is melted under a layer of Al 2 Cl 6 .22>TaCl and 
reunited into a button." 

Bunsen* adopted a similar arrangement. The 
porcelain crucible containing the bath of A1 2 C1 6 . 
2XaCl kept in fusion was divided into two com- 
partments in its upper part by a partition, in order 
to separate the chlorine liberated from the alumin- 
ium reduced. He made the two electrodes of 
retort carbon. To reunite the pulverulent alumin- 
ium, Bunsen melted it in a bath of Al 2 Cl 6 .2XaCl, 
continually throwing in enough XaCl to keep the 
temperature of the bath about the fusing point of 

Deville,f without being acquainted with Bun- 
sen's investigations, employed the same arrange- 
ment, but he abandoned it because the retort 
carbon slowly disintegrated in the bath, and a 
considerable quantity of Al 2 Cl'.2^"aCl was lost by 
the higher heat necessary to reunite the globules 
of aluminium after the electrolysis. Deville also 

* Pogg, 97, 648. 

t Ann. de Phys. et de Chem. [3], 43, 27. 


observed that by working at a higher tempera- 
ture, as Bunsen has done, he obtained purer metal, 
but in less quantity. The effect of the high heat 
is that silicon chloride is formed and volatilizes, and 
the iron which would have been reduced with the 
aluminium is transformed to FeCl 2 by the A1 2 C1 6 , 
and thus the aluminium is purified of silicon and 

Mierzinski makes the following practical remarks 
on the use of electricity in producing aluminium : 

"An important factor which we must notice in 
the present production of aluminium is the appli- 
cation of electricity. On all sides the greatest 
efforts are being made to apply electricity to 
chemical technology ; in the future the importance 
of electricity will centre on its application to reduc- 
ing metals. Even in the year 1807 Davy succeeded 
in decomposing caustic potash by means of a current 
from a 400 element Wollaston battery. But we 
now have magneto-electric and dynamo-electric 
machines which are much lighter and cheaper than 
they were in Davy's time. The application of 
electricity for producing metals also possesses the 
advantage not to be ignored, that a degree of heat 
may be attained with it such as cannot be reached 
by a blowpipe or regenerative gas furnace. The 
highest furnace temperature attainable is 2500 to 
2800 C., but long before this point is reached the 
combustion becomes so languid that the loss of 
heat by radiation almost equals the production of 


heat by combustion, and hinders a further elevation 
of temperature. But in applying electricity, the 
degree of heat attainable is theoretically unlimited. 
A further advantage is that the smelting takes 
place in a perfectly neutral atmosphere, the whole 
operation goes on without much preparation and 
under the eyes of the operator. Finally, in ordi- 
nary furnaces the refractory material of the vessel 
must stand a higher heat than the substance in it, 
whereas by smelting in an electrical furnace the 
material to be fused has a higher temperature than 
the crucible itself. 

" The manufacture of aluminium is effected now 
either by separating out the metal itself directly 
from the solutions of its salts or by reducing it 
with sodium. However, in spite of numerous 
attempts, sodium has not been replaced as a reduc- 
ing agent. In the production of aluminium, the 
making of A1 2 3 from beauxite costs 9.7 per cent., 
making the Al 2 Cl 6 .2XaCi 33.4 per cent,, and de- 
composing by sodium 56.9 per cent, of the whole 
cost. The attempt to reduce alumina directly by 
carbon Mr. W. Weldon considers as impossible 
because he could not produce the temperature 
required for the reaction to take place. Hence 
appears the great importance of utilizing the 
temperature attainable by the electric current. 
The separation of aluminium by electrolysis is now 
done only by the use of anhydrous Al 2 Cl 8 .2!N"aCl, 
melting at 200 C. The anodes are made of plates 


of alumina and carbon pressed together, having the 
conducting wire leading through their whole 
length in order to lessen the resistance as much as 
possible. The metal is obtained as a granular 
powder mixed with Js"aCl. Where possible, vessels 
of chalk or magnesia should be used, since alu- 
minium takes up silicon from siliceous crucibles 
and becomes brittle." 

There have been some improvements made in the 
form of apparatus over those used by Bunsen and 
Deville, designed to produce the metal on a com- 
mercial scale. The best one is that patented in 
Germany by Richard Gratzel.* He uses melting- 
pots of porcelain, alumina, or aluminium, which 
serve also as negative electrodes. A number of 
these are placed in one furnace. The following 
section shows the arrangement (Fig. 16). The 
positive electrode K can be made of a mixture of 
anhydrous alumina and carbon pressed into shape 
and ignited. A mixture of alumina and gas-tar 
answers very well ; or it can even be made of gas- 
tar and gas-retort carbon. During the operation 
little pieces of carbon fall from it and would con- 
taminate the bath, but are kept from doing so by 
the mantle (7. This isolating vessel G is perforated 
around the lower part at #, so that the chlorine gas 
liberated at K may escape through the tube 0', 
while reducing gases can be brought into the cruci- 

* D. R. Pat. No. 26,962. 


ble by the tube O 2 . To lessen the electrical resist- 
ance and to renew the bath of chloride or fluoride, 

Fig. 16. 

bars of carbon, alumina, or magnesia are placed 
inside the isolating mantle G. 

This process is now being worked on a large 
scale in Germany, being also used for producing 
magnesium. There are works at Bremen and 

M. Duvivier* states that by passing an electric 


* The Chemist, Aug. 1854. 


current from eighty Bunsen cells through a small 
piece of laminated disthene between two carbon 
points, the disthene melted entirely in two or three 
minutes, the elements which composed it were 
partly disunited by the power of the electric cur- 
rent, and some aluminium freed from its oxygen. 
Several globules of the metal separated, one of 
which was as white and as hard as silver. 

Kagensbusch,* of Leeds, makes the singular 
proposition to melt clay with fluxes, then add zinc 
or a like metal, pass an electric current through 
the fused mass, isolating an alloy of aluminium and 
the metal, from which the foreign metal may be 
removed by distillation, sublimation, or cupella- 

Gaudinf reduces aluminium by a process to 
which he applies the somewhat doubtful title of 
economic. He melts together equal parts of cryo- 
lite and NaCl, and traverses the fused mass by an 
electric current. Fluorine is evolved at the positive 
pole, while aluminium accumulates at the negative. 

Thus far we have given the methods based on 
elect rolyzing fused salts. These seem to be the 
operations best suited to throwing down aluminium 
in mass. The electrolysis of aqueous solutions 
seems so far to have succeeded only in depositing 
very thin films of metal. We will now give the 

* Eng. Pat. 1872, No. 4811. 
f Moniteur Scieutifique, xi. 62. 


various methods proposed for electrolyzing alu- 
minium in the wet way. 

Messrs. Thomas and Tilly* coat metals with 
aluminium and its alloys by using, for depositing 
the pure metal, a solution of freshly precipitated 
alumina dissolved in boiling water containing 
potassium cyanide, or a solution of freshly calcined 
alum in aqueous potassium cyanide ; also from 
several other liquids. Their patent covers the 
deposition of the alloys of aluminium with silver, 
tin, copper, iron, silver and copper, silver and tin, 
etc. etc. 

M. Corbelli, of Florence,f deposits aluminium 
by electrolyzing a mixture of rock alum or sulphate 
of alumina with CaCl 2 or UaCl, in aqueous solu- 
tion, the anode being mercury placed at the bottom 
of the solution and connected to the battery by an 
iron wire coated with insulating material and 
dipping its uncovered end into the mercury. The 
zinc cathode is immersed in the solution. Alu- 
minium is deposited on the zinc, and the chlorine 
which is liberated at the anode unites with the 
mercury, forming calomel. 

J. B. Thompson^ reports that he has for over 
two years been depositing aluminium on iron, steel, 
and other metals, and also depositing aluminium 

* Eng. Pat., 1855, No. 2756. 
f Eng. Pat., 1858, No. 507. 
J Chem. News, xxiv. 194. 


bronze of various tints, but declines to state his 

J. A. Jeancon* has patented a process for de- 
positing aluminium from an aqueous solution of a 
double salt of aluminium and potassium of specific 
gravity 1.161 ; or from any solution of an alumin- 
ium salt, such as sulphate, nitrate, cyanide, etc., 
concentrated to 20 B. at 50 F. He uses a battery 
of four pairs of Smee's or three Bunsen's cells, 
with elements arranged for intensity, and electro- 
lyses the solutions at 140 F. The first solution 
will decompose without an aluminium anode, but 
the others require such an anode on the negative 
pole. The solution must be acidulated slightly 
with acid corresponding to the salt used, the tem- 
perature being kept at 140 F. constantly. 

M. A. Bertrandf states that he deposited alu- 
minium on a plate of copper from a solution of 
double chloride of aluminium and ammonia, by 
using a strong current, and the deposit was capable 
of receiving a brilliant polish. 

C. W inkier J states that he has spent much time 
and tried all methods so far proposed, and comes 
to the conclusion that aluminium cannot be de- 
posited by electro-deposition in the wet way. 

* Annual Record of Science and Industry, 1875. 

t Chera. News, xxxiv. 227. 

t Journal of the Chem. Soc., x. 1134. 


Sprague* also states his inability to deposit alumin- 
ium electrically from solution. 

M. L. Senetf electrolyzes a saturated solution of 
AP(S0 4 ) 3 , separated by a porous septum from a 
solution of NaCl. A current is used of four 
amperes. The double chloride, Al 2 Cl 6 .2NaCl, is 
formed, then decomposed, and the aluminium 
liberated deposited on the negative electrode. 

Gerhard and Smith:): patented a process for de- 
positing electrically aluminium and its alloys. 

John Braun decomposes a solution of alum, of 
specific gravity 1.03 to 1.07, at the usual tempera- 
ture, using an insoluble anode. In the course of 
the operation, the sulphuric acid set free is neu- 
tralized by the continual addition of alkali ; and, 
afterwards, to avoid the precipitation of alumina, 
a non-volatile organic acid is added to the solution. 

Moses Gr. Fanner) has patented an apparatus for 
obtaining aluminium electrically consisting of a 
series of conducting cells in the form of ladles, 
each ladle having a handle of conducting material 
extending upwards above the bowl of the next 
succeeding ladle ; each ladle can be heated sepa- 
rately from the rest ; the anodes are hung in the 
ladles, being suspended from the handles of the 

* Sprague's Electricity, p. 309. 
f Cosmos les Mondes, Aug. 10, 1885. 
\ Eng. Pat., 1884, No. 16,653. 
German Pat., No. 28,760. 
II U. S. Pat., No. 315,266, Apr. 1885. 


preceding ladles, the ladles themselves being the 

Mierzinski says that the deposition of aluminium 
from an aqueous solution of its salt has not yet 
been accomplished, and declares Gore to have been 
in error when he stated that he had covered copper 
with a film of aluminium by using a feeble current 
and a solution of APC1 6 in water. 

Several years ago, the writer was in Mr. Frish- 
muth's works, in Philadelphia, and observed that 
he was then doing a large amount of plating, de- 
positing an alloy of aluminium and nickel. Nickel 
plating is known to be very hard and lasting, but 
it has a dark-bluish color, not agreeable to many. 
The presence of aluminium with it whitens it so 
that the plating is a very close imitation of silver, 
and wears much better than silver plating. He 
was depositing with a twenty horse-power dynamo. 
The articles were previously cleaned in a hot pot- 
ash solution, and then hung in the plating bath. 
I do not know the composition of his solution, he 
keeps that secret, but it was green and strongly 




DEVILLE : To melt aluminium it is necessary to 
use an ordinary earthen crucible and no flux. 
Fluxes are always useless and almost always harm- 
ful. The extraordinary chemical properties of the 
metal are the cause of this ; it attacks very actively 
borax or glass with which one might cover it to 
prevent its oxidation. Fortunately this oxidation 
does not take place even at a high temperature. 
When its surface has been skimmed of all impuri- 
ties it does not tarnish. Aluminium is very slow 
to melt, not only because its specific heat is consid- 
erable, but its latent heat appears very large. It 
is best to make a small fire and then wait patiently 
till it melts. One can very well work with an un- 
covered crucible. When it is desired to melt 
pieces together, they can be united by agitating the 
crucible or compressing the mass with a well-cleaned, 
cylindrical bar of iron. Clippings, filings, etc., are 
melted thus : Separate out first, as far as possible, 
foreign metals, and to avoid their combining with 


the aluminium heat the divided metal to as low 
a heat as possible, just sufficient to melt it. The 
oil and organic matters will burn, leaving a cinder, 
which hinders the reunion of the metal if one does 
not press firmly with the iron bar. The metal may 
then be cast very easily, and there is found at the 
bottom of the crucible a little cinder which still 
contains a quantity of aluminium in globules. 
These may be easily separated by rubbing in a 
mortar and then passing through a sieve, which 
retains the flattened globules. 

Kerl & Stohman : To be able to melt well and 
pour aluminium, the whole quantity of metal which 
is to be melted at one time must not be put into 
the crucible at once, but little by little, so increas- 
ing the mass from time to time as the contents 
become fully melted. The necessary knack for 
attaining a good clean melt consists in dipping the 
pieces which are to be melted together in benzine 
before putting in the crucible. Mourey even pours 
a small quantity of benzine into the crucible after 
the full melting of the metal, and he recommends 
the employment of benzine in the melting of all 
the noble metals. Turning to the cases arising in 
the employment of aluminium in the different in- 
dustrial arts, one must as far as possible separate 
out first the pieces which have been soldered, in 
order that the newly melted aluminium may riot 
be contaminated by the solder. The solder adher- 
ing to these pieces can be removed by treating them 


with, nitric acid, by which the aluminium is not 

Mierzinski : To melt aluminium one cannot heat 
it in common clay crucibles, because it reduces sil- 
icon from them, by which the metal becomes gray 
and brittle. This difficulty can be removed by 
lining the crucible with carbon, or better, with well- 
burnt cryolite-clay. Moreover, in practice, it is 
only in the rarest cases that pure aluminium is 
obtained to be melted up, but, as a rule, it is al- 
loyed with four to eight per cent, of silver. 


Deville : Aluminium can be cast very easily in 
metallic moulds, but better in sand for complicated 
objects. The mould ought to be very dry, made of 
a porous sand, and should allow free exit to the air 
expelled by the metal, which is viscous when 
melted. The number of vents ought to be very 
large, and a long, perfectly round git should be 
provided. The aluminium, heated to redness, 
ought to be poured rather quickly, letting a little 
melted metal remain in the git till it is full, to pro- 
vide for the contraction of the metal as it solidifies. 
In general, this precaution ought to be taken even 
when aluminium is cast in iron ingot moulds or 
moulds of any other metal. The closed ingot 
moulds give the best metal for rolling or hammer- 
ing. By following these precautions, castings of 


great beauty may be obtained, but it is not advisa- 
ble to conceal tbe fact that to be able to succeed 
completely in all these various operations requires 
for aluminium, as for all other metals, a special 
familiarity with the material which practice alone 
is able to give. 

In the fusion of impure aluminium, very different 
phenomena are observed according to the nature of 
the foreign metal which contaminates it. Ferru- 
ginous material often leaves a skeleton less fusible 
and pretty rich in iron ; a liquation has taken 
place, increasing the purity of the melted material. 
When the aluminium contains silicon this liquation 
is no longer possible, or at least it is very difficult, 
and I have sometimes seen some commercial alu- 
minium so siliceous that the workmen were unable 
to remelt it. But the aluminium which is made 
at present is much purer than that. 


Freeing from Slag. Deville gives the following 
information on this important subject: 

"It is of great importance not to sell any 
aluminium except that which is entirely free from 
the slag with which it was produced and with 
which its whole mass may become impregnated. 
We have tried all sorts of ways of attaining this 
end, so as to obtain a metal which would not give 
any fluorides or chlorides upon boiling with water, 


or give a solution which would be precipitated by 
silver nitrate. At Glaciere, we granulated the 
metal by pouring it while in good fusion into 
water acidulated with H 2 S0 4 ; this method par- 
tially succeeded. But the process which M. Paul 
Morin uses at present, and which seems to give 
the best results, is yet simpler. Three or four 
kilos of aluminium are melted in a plumbago cru- 
cible without a lid, and kept a long time red hot 
in contact with the air. Almost always acid 
fumes exhale from the surface, indicating the 
decomposition by air or moisture of the saline 
matter impregnating the metal. The crucible 
being withdrawn from the fire, a skimmer is put 
into the metal. This skimmer is of cast iron ; its 
surface ought not to be rough and it will not be 
wetted by the aluminium in the least during the 
skimming. The white and slaggy matters are 
then removed, carrying away also a little metal, 
and are put aside to be remelted. So, in this 
purification, there is really no loss of metal. After 
having thus been skimmed, the aluminium is cast 
into ingots. This operation is repeated three or 
four times until the metal is perfectly clean, which 
is, however, not easily told by its appearance, for, 
after the first fusion, the crude aluminium when 
cast into ingots has a brilliancy and color such as 
one would judge quite irreproachable, but the 
metal would not be clean when it was worked, 
and especially when polished would present a mul- 


titude of little points called technically 'piqures,' 
which give to its surface, especially with time, a 
disagreeable look. Aluminium, pure and free 
from slag, improves in color on using. It is the 
contrary with the impure metal or with alumin- 
ium not freed from slag. When aluminium is 
submitted to a slow, corroding action, its surface 
will cover itself uniformly with a white, thin 
coating of alumina. However, any time that this 
layer is black or the aluminium tarnishes, we may 
be sure that it contains a foreign metal and that 
the alteration is due to this impurity." 

Watts suggests that the iron skimmer be oxi- 
dized on its surface. 

Freeing from Impurities. Again Deville is the 
authority, and we quote his advice on the sub- 
ject : 

" A particular characteristic of the metallurgy 
of aluminium is that it is necessary, in order to get 
pure metal, to obtain it so at the first attempt. 
When it contains silicon, I know of no way to 
eliminate it, all the experiments which I have 
made on the subject have had a negative result ; 
simple fusion of the metal in a crucible, permitting 
the separation by liquation of metals more dense, 
seems rather to increase the amount of silicon than 
to decrease it. When the aluminium contains iron 
or copper, each fusion purifies it up to a certain 
limit, and if the operation is done at a low heat 
there is found at the bottom of the crucible a 


metallic skeleton containing much more iron and 
copper than the primitive alloy. At first I made 
this liquation in the muffle of a cupel furnace, in 
which process the access of air permitted the par- 
tial oxidation of these two metals. The little lead 
which aluminium may sometimes take up may 
thus be easily separated. Unfortunately, the pro- 
cess does not give completely satisfactory results. 
It is the same in fusing impure aluminium under 
a layer of potassium sulphide, K 3 S 3 ; there is a 
partial separation of the lead, copper, and iron. 
That which has succeeded best with us is the pro- 
cess which we have employed for a long time at 
Glaciere, and which consists in melting the alu- 
minium under nitre in an iron crucible. We have 
in this way improved the quality of large quanti- 
ties of aluminium. The operation is conducted as 
follows: Aluminium has generally been melted 
with nitre in order to purify it by means of the 
strong disengagement of oxygen at a red heat, no 
doubts being entertained as to the certainty of the 
result. But it is necessary to take great care 
when doing this in an earthen crucible. The 
silica of the crucible is dissolved by the nitre, the 
glass thus formed is decomposed by the aluminium, 
and the siliceous aluminium thus formed is, as we 
know, very oxidizable, and especially in the pres- 
ence of alkalies. So, the purification of aluminium 
by nitre ought to be done in a cast-iron crucible 
well oxidized itself by nitre on the inside. 


" On melting aluminium containing zinc in con- 
tact with the air and at a temperature which will 
volatilize the zinc, the largest part of the latter 
burns and disappears as flaky oxide. To obtain a 
complete separation of the two metals it is neces- 
sary to heat the alloy to a high temperature in a 
brasqued crucible. This experiment succeeds very 
W 7 ell,but it is here shown that the aluminium must 
oxidize slightly on its surface, for some carbon is 
reduced by the aluminium from the carbonic 
oxide with w ? hich the crucible is filled. This 
carbon thus separated is quite amorphous." 

This phenomenon may not appear so extraor- 
dinary if we consider the case in this way : The 
aluminium is dissolved in the fluid zinc in a man- 
ner strictly analogous to the aluminium dissolved 
in mercury. Kow, it will be seen that alumin- 
ium-amalgam decomposes easily, the mercury ap- 
pearing to impart to the aluminium the ability to 
combine easily with oxygen, so that .in the 
amalgam aluminium is said to play the part of an 
alkali metal, with which it is so closely related in 
its compounds. Considering the case of the alu- 
minium dissolved in melted zinc instead of in 
mercury, it appears probable that the zinc imparts 
in the same manner as the mercury, though not 
necessarily in the same degree, the alkali charac- 
teristics to the metal, causing it to oxidize even at 
the expense of carbonic oxide. 

Mierzinski recommends the purification with 


nitre to be made in a crucible made of alumina or 
aluminate of soda. 

Gr. Bucbner* states that commercial aluminium 
contains considerable quantities of silicon, which 
by treatment, when melted, with hydrogen, evolves 
hydrogen silicide. This does not result if arsenic 
is present. 

Mallet made chemically pure aluminium by treat- 
ing the commercial metal with bromine, purifying 
the resulting APBr 6 by fractional distillation, and 
then reducing it with pure sodium. By repeatedly 
melting the metal upon aluminium leaf, he obtained 
it chemically pure. Although this method is quite 
applicable when studying the properties of the 
pure metal, yet it cannot serve on an industrial 


" Since aluminium was prepared by Devillef on a 
large scale it has received numerous applications. 
Its beautiful color, its lightness, its unoxidizability 
in contact with air or sulphuric acid, its harmless- 
ness to the health, the ease with which it may be 
worked, are some of the properties which assure for 
it a place among the useful metals. On account of 
its very high price the first articles made of it were 
those of ornament and luxury. The very first article 

* Wagner's Jahresb., 1884. 
t Fremy's Ency., 1883. 


made of it was a baby rattle, intended for the young 
Prince Imperial in 1856. Afterwards there were 
made of it jewelry, medals, inlaid work, and carved 
mouldings for inlaid work and rich furniture. It is 
very well suited for fine jewelry by reason of its 
adaptability to being cast and carved, the beautiful 
reflections from a chased surface, its color, which 
matches well with gold, and its absence of all odor. 
Later on, the lightness of aluminium leads to its 
use for telescope tubes, marine glasses, eye-glasses, 
and especially sextants. In delicate physical ap- 
paratus, where it is necessary to avoid the inertia 
of large masses, aluminium replaces the other 
metals with advantage. It is used for beams 
for delicate balances and for very small weights. 
There have been made of it sabre sheaths, sword 
handles, and the imperial eagles for the French 
army. Finally, made into fine wire, it is worked 
into lace, embroidery, etc. For all these purposes 
aluminium answers better than silver, for the 
objects are much lighter and do not tarnish. The 
resistance of aluminium to most of the agents 
which attack the useful metals has led to its em- 
ployment for culinary articles ; a large number of 
which were seen at the London Exhibition in 1862. 
But the advantages of aluminium vessels have not 
yet been sufficiently comprehended, and this use 
of it has at present been entirely discontinued. 
Likewise, aluminium jewelry is not seen any 
more; so that the metal seems reserved for little 


more than optical and surgical instruments. But 
the aluminium industry is nevertheless established 
on a permanent basis and will continue, because of 
the numerous applications of its alloys." 

M. Dumas made a helmet of aluminium, gilded 

' o 

and ornamented, which weighed complete only one 
and one-fifth pounds. 

Aluminium leaf, beaten very thin, may be used 
anywhere in place of silver leaf. It is applied in 
the same manner, and is more durable. 

Aluminium wire has been proposed for telegraph 
lines. The conductivity of aluminium is double 
that of iron, and as it is so much lighter, thinner 
wire can be used. As its high price is a practical 
difficulty, an alloy of iron and aluminium has been 

" One of the most likely applications of alu- 
minium is probably as a material for statuettes and 
small works of art of this description, especially if 
the means could be found of giving to it a richer 
color and appearance either by a kind of bronzing 
or some alloy. 

" Aluminium makes very bright reflectors, not 
tarnished by the products of combustion, while the 
slight bluish tinge of the metal corrects the yel- 
lowish tinge of the flame. For culinary uses it is 
well adapted, because of its lightness and the little 
tendency it has to become corroded by any of the 
liquids likely to come in contact with it. It is 
necessary to observe, however, that this power of 



resisting the action of corroding agencies, and 
more especially the atmosphere of large towns, is 
exhibited only by the pure metal. Most of the 
metal of commerce is very impure with iron and 
silicon, not having been properly freed from slag. 
Aluminium thus contaminated soon becomes tar- 
nished, and much disappointment has been experi- 
enced from this cause by those who have used it 
for ornamental purposes. According to Deville, the 
impurities just mentioned are found to the greatest 
amount in the metal obtained from cryolite." 

In the ' Scientific American/ vol. xii. pp. 31 and 
51, is a long article on plating with a luminium, 
giving complete directions for preparing articles, 
solutions, etc. 

A large collection of articles of aluminium was 
shipped from England to Calcutta in Oct. 1883, 
intended for exhibition there. The exhibit con- 
sisted of wire, pens, pencil-cases, railway-carriage 
fittings, locks and bolts, harness furniture in great 
variety, chandeliers, cutlery, and ships' fittings, 
and illustrated very well the various uses to which 
the metal can be put. It is being used for the 
lighter parts of such instruments as galvanometers, 
etc., for suture wire, and perhaps its most promis- 
ing field is for engineering, astronomical, and 
optical instruments. 

" Aluminium is sold as leaf in books, like gold 
leaf, for decorations, at from 40 to 50 cents per 
book, and is being experimented with by manu- 


facturers of jewelry. In Germany, experiments 
have been made with it as a coating for iron, to be 
applied for ornamental purposes, and as an improve- 
ment on tin plate. Its use is extending slowly but 
surely, its cost being at present the principal 
obstacle to its wider employment."* 

Experiments were made in the U. S. Mint in 
1865, on alloys of aluminium for coins. The 
results w r ere not sufficiently successful to induce 
the Government to adopt the metal for that purpose. 


At the time Deville wrote his book, the difficulty 
of soldering aluminium properly was one of the 
greatest, if not the greatest, obstacle to the employ- 
ment of the metal. His views on the question may 
be, therefore, very interesting ; they are as follows : 

"Aluminium may be soldered, but in a very 
imperfect manner, either by means of zinc or 
cadmium, or alloys of aluminium with these 
metals. But a very peculiar difficulty arises here, 
w r e know no flux to clean the aluminium which 
does not attack the solder, or which, protecting the 
solder, does not attack the aluminium. There is also 
an obstacle in the particular resistance of aluminium 
to being wetted by the more fusible rnetals, and 
on this account the solder does not run between 

* Mineral Resources of the U. S. 1883-4. 


and attach itself to the surfaces to be united. .M- 
Christofle and M. Charriere made, in 1855, during 
the Exposition, solderings with zinc or tin. But 
this is a weak solder and does not make a firm 
seam. MM. Tissier, after some experiments made 
in my laboratory, proposed alloys of aluminium 
and zinc, which did not succeed any better. How- 
ever, M. Denis, of Nancy, has remarked that when- 
ever the aluminium and the solder melted on its 
surface are touched by a piece of zinc, the adhesion 
becomes manifest very rapidly, as if a particular 
electrical state was determined at the moment of 
contact. But even this produces only weak solder- 
ings, insufficient in most cases. 

" A long time ago, M. Hulot proposed to avoid 
the difficulty by previously covering the piece 
with copper, then soldering the copper surfaces. 
To effect this, plunge the article, or at least the 
part to be soldered, into a bath of acid sulphate of 
copper. Put the positive pole of a battery in com- 
munication with the bath, and with the negative 
pole touch the places to be covered, and the copper 
is deposited very regularly. M. Mourey has suc- 
ceeded in soldering aluminium by processes yet 
unknown to me ; samples which I have seen looked 
excellent. I hope, then, that this problem has 
found, thanks to his ingenuity, a solution ; a very 
important step in enlarging the employment of 


Mierzinski gives the following statements about 
M. Mourey's solder: 

" Mourey, who first made a practicable solder 
for aluminium, used two kinds of solder, soft and 
hard. The first was used for the usual soldering 
up of flasks or pieces of metal. He made solders 
of five different alloys, the composition of which 
were as given in the table below : 

I. II. III. TV. V. 
Al ... 20 15 12 8 6 

Zn ... 80 85 88 92 94 

These solders have varying melting points, and 
thus there results the hard and soft solders. One 
can take a soft solder, as IV., for brazing, and one 
like II. for ordinary soldering."* 

Schwarzf improved these solders by adding 
copper to the alloy. His solders have the follow- 
ing composition : 

I. II. III. IV. V. 

Al ... 12 9 7 6 4 

Cu ... 8 6 5 4 2 

Zn ... 80 85 88 90 94 

MoureyJ recommends improved solders of some- 
what similar composition. They are : 








Al . . . 








Cu . . 








Brass . 








Zn . . . 








* It is usual to employ hard solder for brazing, and No. II. 
would be harder than No. IV. J. W. R. 

t Dingier, 157, 445. \ Dingier, 166, 205. 


Col. "Wm. Frishmuth* recommends a solder con- 
taining : 

Al . . . . . . . .20 

Cu 10 

Zn 30 

Sn 60 

Ag 10 

Col. Frishmuthf states that the solder just given 
is used for fine ornamental work , while for lower- 
grade work he uses the following : 

I. n. in. 

Sn .... 95 97 98-99 
Bi .... 5 3 2-1 

Frishmuth recommends for a flux, in all cases, 
either paraffin, stearin, vaseHn, copaiva balsam, or 
benzine. In the solder for fine work, if aluminium 
is used in larger quantity than recommended, the 
solder becomes brittle. 

Kerl and Stohman give the following practical 
observations on this subject: 

" At first, the soldering of aluminium appeared 
impossible. But Ph. Mourey, a gold and silver 
worker in Paris, invented a new method by which 
he could solder any kind of object of this metal. 
The following are his receipts: 

" There are needed, according to the objects to be 
soldered, five different solders, which are composed 
of aluminium, copper, and zinc, in different propor- 
tions : 

* Teclmiker, vi. 249. f Wagner's Jahresb., 1884. 


I. II. III. IV. V. 

Al. . . 12 9 7 6 4 

Cu. . . 8 6 5 4 2 

Zn . . . 80 85 88 90 94 

"To make the solder, first pat the copper in the 
crucible. When it is melted, then add the alu- 
minium in three or four portions, thereby some- 
what cooling the melted mass. When both metals 
are melted, the mass is stirred with a small iron 
rod, and then the required quantity of zinc added, 
free from iron, and as clean as possible. It melts 
very rapidly. The alloy is then stirred briskly 
with an iron rod for a time, some fat or benzine 
being meanwhile put in the crucible to prevent 
contact of the metal with air and oxidation of the 
zinc. Finally the whole is poured out into an in- 
got mould previously rubbed with benzine. After 
the addition of zinc, the operation must be finished 
very rapidly, because the latter will volatilize and 
hum out. As soon as the zinc is melted, the cru- 
cible is taken out of the fire. 

"The separate pieces of metal to be soldered 
together are first well cleaned, then made some- 
what rough with a file at the place of juncture, 
and the appropriate solder put on it in pieces about 
the size of millet grains. The objects are laid on 
some hot charcoal, and the melting of the solder 
effected by a blast lamp or a Rochemont turpentine- 
oil lamp. During the melting of the solder, it is 
rubbed with a little soldering iron of pure alumin- 


ium. The soldering iron of pure aluminium is 
essentially a necessity for the success of the opera- 
tion, since an iron of any other metal will allo} 7 
with the metals composing the solder, while the 
melted solder does not stick to the iron made of 

" The method just described differs from the one 
described by Mourey in so far that he used, at first, 
alloys of aluminium and zinc only, with no copper. 
He used one of the more fusible alloys to first unite 
the pieces, and then used a less fusible one to finish 
with. In order to avoid the oxidation of the sol- 
der he added while using the hard solder, which 
must be worked with a hotter iron, a quantity of 
copaiva balsam and turpentine, which acts just as 
borax in working silver. With these new solders 
of aluminium, copper, and zinc the process is much 
simpler, the work is done w T ith one solder and the 
moistening with balsam is unnecessary. The sol- 
derings may be done so perfectly that plates soldered 
together never break at the joint when bent back 
and forth, but always give way in other places ; 
which is a result not always possible in the best 
soldering of plates of silver." 

Bell Bros, used to operate the works at N"ewcas- 
tle-on-Tyne, and their description may contain a 
few points not yet brought forward : * 

"In order to unite pieces of aluminium, small 

* Chem. News, iv. 81. 


tools of the same metal are used, which facilitate 
at the same time the fusion of the solder and its 
adhesion to the previously prepared surfaces. Tools 
of copper or brass must be strictly avoided, as they 
would form colored alloys with the aluminium and 
the solder. The use of the little tools of alumin- 
ium is an art which the workman must acquire by 
practice. At the moment of fusion the work needs 
the application of friction, as the solder suddenly 
melts very completely. In soldering it is well to 
have both hands free and to use only the foot for 
the blowing apparatus. The solders used are of 
aluminium, copper, and zinc. (See the ones given 
by Kerl & Stohman, p. 250.) No. IY. is the one 
generally preferred, particularly for small objects. 
In order to make the solder, the copper is first 
melted, the aluminium added, and the whole 
stirred with an unpolished iron rod, just as it 
comes from the forge, adding also a little tallow. 
The zinc is then added, avoiding too much heat, 
which would drive it off. In soldering, also, too 
high a heat should be avoided for the same reason. 


Deville is the first writer to make mention of 
this art : 

" M. Sevrard succeeded in 1854 in plating alumin- 
ium on copper and brass with great perfection. 
The two metallic surfaces being prepared in the 


ordinary manner and well scoured with sand, they 
are placed one on the other and held tightly be- 
tween two iron plates. The packet is then heated 
to dark redness, at which temperature it is strongly 
compressed. The veneer becomes very firmly at- 
tached, and sheets of it may be beaten out. I have 
a specimen of such work perfectly preserved. The 
delicate point of the operation is to just heat the 
packet to that point that the adherence may be 
produced without fusing the aluminium, for when 
it is not heated quite near to this fusing point, the 
adherence is incomplete. Experiments of this 
kind with copper and aluminium foil did not suc- 
ceed, for as soon as any adherence manifested itself 
the two metals combined and the foil disappeared 
into the copper. In an operation made at too low a 
temperature, the two metals, as they do not behave 
similarly on rolling, become detached after a few 
passes through the rolls. Since then, the experi- 
ments in veneering aluminium on copper, with or 
without the intervention of silver, have succeeded 
very well." 

The only other article to be found on this subject 
is Dr. Clemens Winckler's paper, from which we 
extract the following : * 

u The question demands attention whether it is 
not possible to coat certain metals and alloys w r ith 
aluminium, and thereby impart to them, superfi- 

* Industrie Blatter, 1873. 


cially at least, the advantageous properties of that 
metal. The present high price of the metal does 
not stand in its way for this purpose ; and it only 
remains now to decide whether it is practicable to 
coat our common metals, iron, copper, etc., with it. 
The question must at present be answered in the 
negative. Two methods can be used for covering 
one metal with another, galvanoplasty and plating 
or veneering. The separation of aluminium by 
the galvanic current succeeds only by the use of a 
bath of molten anhydrous Al 2 Cl 6 .2^N"aCl, melting 
at 165 C. (329 F.), but the metal is deposited as a 
non-coherent powder, mixed with ISTaCl, and there- 
fore the object of plating is not attained in this way. 
Ko one has yet been able to throw down aluminium 
in a metallic state from aqueous solution, and it was 
an error when Grore stated that he had coated cop- 
per with aluminium by means of a solution of A1 2 C1 6 
in water and a weak galvanic current. Concerning 
the coating of metals by the so-called plating 
method, it is indeed, according to my own experi- 
ence, possible to a certain degree, but the product . 
is entirely useless, every plating requiring an incip- 
ient fusing of both metals and their final intimate 
union by rolling. The ductility of aluminium is, 
however, greatly injured by even a slight admixture 
with other metals ; iron makes it brittle and copper, 
in small per cent, makes it fragile as glass. If now 
it were possible in any way to fuse a coating of 
aluminium upon another metal, there would be 


formed an intermediate alloy between the two 
metals from which all ductility would be gone and 
which would crumble to powder under the pressure 
of the rolls, thus separating the aluminium surface 
from the metal beneath. But even if it were pos- 
sible in this way to coat a metal with a thin plate, 
it is still doubtful if anything would be attained 
thereby. For, while compact aluminium resists 
oxidizing and sulphurizing agencies, the divided 
metal does not. In powder or leaves aluminium is 
readily oxidized, as is shown by its amalgam be- 
coming heated in the air and quickly forming alu- 
mina. In the form of a coating upon other metals 
it must necessarily be in a somewhat finely divided 
state, and hence would probably lose its durability." 


Deville says: "The gilding and silvering of 
aluminium by electricity is very difficult to do 
satisfactorily and obtain the desirable solidity. M. 
Paul Morin and I have often tried it by using a 
bath of acid sulphide of gold or of nitrate of silver 
with an excess of sulphurous acid. Our success 
has only been partial. However, M. Mourey, who 
has already rendered great services in galvano- 
plasty, gilds and silvers the aluminium of com- 
merce with a surprising perfection considering the 
little time he has had to study the question. I 
also know that Mr. Christofle has gilded it, but I 


am entirely ignorant of the methods employed by 
these gentlemen." 

Watts's Dictionary : " Eight grammes of gold are 
dissolved in aqua regia, the solution diluted with 
water and left to digest twenty-four hours with an 
excess of lime. The precipitate, with the lime, is 
well washed, and then treated with a solution ot 
twenty grammes of hyposulphate of soda. The 
liquid resulting serves for the gilding of aluminium 
without the aid of heat or electricity, the metal 
being simply immersed in it after being previously 
well cleaned by the successive use of caustic potash, 
nitric acid, and pure water." 

Kerl and 8 tohmau : " Gilding and silvering 
aluminium galvanically does not offer the least 
difficulty. One can, by using a proper ground, 
coat it with silver and gold in six different colors, 
by employing the correct combination, such as 
shining or matt gold and silver or lead gray." 




General Remark. Mierzinski : 

"Aluminium unites easily with most metals, the 
combination being usually accompanied by a lively 
disengagement of heat. Quite homogeneous alloys 
can be made, which for the most part are easily 
worked and have important applications. The 
alloys in general become harder the greater the 
proportion of aluminium, and become brittle if this 
proportion passes a certain limit, which with gold 
and copper is very low. On addition of a larger 
amount of aluminium than this limit allows, gold 
and copper become whiter, and at last entirely lose 
their color. The addition of other metals to alu- 
minium imparts to it the same new properties. It 
becomes brighter and somewhat harder, but, united 
with small quantities of zinc, tin, gold, or silver, 
remains malleable. Iron and copper impart to it 
no specially prejudicial qualities, if they are not 
present in too large quantities. The alloys most 
frequently used are those of copper, silver, and tin. 
These owe their numerous uses to their fine color, 
their resistance to most chemical agents, and the 
facility with which they may be worked." 



Tissier: "As Deville has observed, silicon is far 
from injurious to the malleability of aluminium, 
the latter bearing it much as iron and copper do. 
We have had occasion to analyze a specimen of 
aluminium, which, although it worked with diffi- 
culty, was yet employed to make various objects, 
and yet, attacked by HC1, it left an insoluble resi- 
due of no less than 15.67 per cent. But, even 
admitting that this residue still retained some alu- 


minium with the silicon, we think that there was 
at least 10 per cent, of the latter in this specimen." 
Deville : " Any siliceous material whatever, put 
in contact with aluminium at a high temperature, 
is always decomposed ; and if the metal is in excess 
there is formed an alloy or a combination of silicon 
and aluminium in which the two bodies may be 
united in almost any proportions. Glass, clay, and 
the earth of crucibles act in this way. However, 
aluminium may be melted in glassware or earthen 
crucibles without the least contamination of the 
metal if there is no contact between the metal and 
the material ; the aluminium will not wet the 
crucible if put into it alone. But, the moment that 
any flux whatever facilitates immediate contact, 
even sodium chloride does this, the reaction begins 
to take place, and the metal obtained is always 
more or less siliceous. It is for this reason that I 
have prescribed in melting aluminium not to add 


any kind of flux, even when the flux would not be 
attacked by the metal. Among the fusible ma- 
terials which facilitate the me] ting of aluminium, 
it is necessary to remark of the fluorides that they 
attack the siliceous materials of the crucible, dis- 
solving them with* great energy, and then the 
siliceous materials thus brought into solution are 
decomposed by the aluminium with quite remark- 
able facility. Aluminium charged with silicon 
presents quite different qualities according to the 
proportion of the alloy. When the aluminium is 
in large excess, there is obtained what I have called 
the ' cast-iron' state of aluminium, by means of which 
I discovered crystallized silicon in 1854. This 
4 cast' aluminium, gray and brittle, contains accord- 
ing to my analysis 10.3 per cent, of silicon and 
traces of iron. When siliceous aluminium is at- 
tacked by hydrochloric acid, the hydrogen which 
it disengages has an infected odor, which I formerly 
attributed to the presence of a hydrocarbon, but 
which we now know is due to hydrogen silicide, Sill 4 , 
thanks to the fine experiments of MM. Wohler 
and Buff. It is by the production of this gas that 
may be explained the iron smell which is given 
out by aluminium more or less contaminated with 
silicon. But aluminium may absorb much larger 
proportions of silicon, for, on treating fluo-silicate 
of potash with aluminium, M. Wohler obtained a 
material still metallic containing about 70 per cent, 
of silicon, sometimes occurring as easily separable 


crystals. Since I had the occasion in a work which 
I published on silicon to examine a large number 
of these combinations, I found that they were much 
more alterable than pure aluminium or silicon, 
without doubt because of the affinity which exists 
between silica and alumina. I have, therefore, 
dwelt on and tried to explain the importance 
of this point in obtaining perfectly pure alumin- 
ium. I should say, in addition, that the metal 
now sold in commerce may contain either iron or 
silicon, according to the method of preparation. 
These two impurities are hurtful to most of the 
qualities of the aluminium, and everything ought 
to be done to avoid their presence." 


Deville : " Mercury is not able to unite with 
aluminium. Experiments of this nature which I 
have made myself, and which Mr. Wollaston has 
confirmed, prove it most clearly." 

Watts : " According to Caillet, aluminium may 
be amalgamated by the action of ammonium or 
sodium amalgam, with water; also when it is con- 
nected with the negative pole of a voltaic battery 
and dipped into the mercury moistened with acid- 
ulated water, or into a solution of mercuric nitrate. 
Tipsier* confirms this statement respecting the 

* Compt. Rend., xlix. 56. 


battery method, and adds that if the aluminium 
foil is not very thick it becomes amalgamated 
throughout and very brittle." Tissier also finds 
that aluminium may be made to unite with mer- 
cury merely by the intervention of a solution of 
caustic potash or soda, without the intervention of 
the battery. If the surface of the metal be well 
cleaned, or moistened with the alkaline solution, it 
is immediately melted by the mercury, and a shin- 
ing amalgam forms on its surface. The amalgam 
of aluminium instantly loses its lustre when ex- 
posed to the air, becoming heated and rapidly 
converted into alumina and mercury. It decom- 
poses water with evolution of hydrogen and forma- 
tion of alumina and mercury. Nitric acid attacks 
it with violence. 

Watts (First Supplement) states that aluminium 
amalgam may be formed either by bringing the 
aluminium in contact with mercury containing a 
small quantity of sodium, or by Joules's method of 
electrolyzing the solution of an aluminium salt, 
with mercury for the negative pole ;* but the best 
method is to heat the two metals together in a gas 
which does not act on either of them. To do this, 
a piece of aluminium foil is placed at the bottom 
of a thick-walled test-tube, and well-dried mercury 
is poured on it, the tube having been previously 
drawn out at the middle to prevent the foil rising 

* Chem. Gazette, 1850, p. 339. 


to the surface. The air is then expelled by a 
stream of carbonic acid gas and the tube is heated, 
without interrupting the current of gas, till the 
metal is all dissolved. 

Aluminium amalgam decomposes in contact 
with air or water more quickly than sodium amal- 
gam. When a few drops of an amalgam contain- 
ing but a small proportion of aluminium are left 
in contact with moist air, gelatinous, opalescent 
excrescences of pure hydrated alumina are seen to 
form on their surfaces, exhibiting both in their 
form and mode of growth considerable resemblance 
to the so-called Pharoah's serpents. This hydrated 
alumina is perfectly soluble in acids and alkalies. 
Water has the same effect as moist air. Watts, in 
vol. viii., states that aluminium oxidizes when 
its surface is rubbed with a piece of soft leather 
impregnated with mercury. The rubbed surface 
becomes warm, and in a few seconds whitish ex- 
crescences appear, consisting of pure alumina. 
The presence of mercury appears necessary to 
produce the result. 

Fremy says that Tissier has proven that alumin- 
ium previously contaminated with caustic potash 
or soda combines easily with mercury. The alloy 
which results is very brittle, the aluminium in it 
decomposes water, oxidizes easily in the air, and 
behaves as a metal of the alkaline earths. 

Gmelin* states that potassium amalgam intro- 

* Hand Book, vi. 3. 


duced into a hole bored in a crystal of alum 
immediately acquires a rotary motion, which lasts 
sometimes half an hour. At the same time, it 
takes up a considerable quantity of aluminium and 
becomes more viscid. 


Tissier Bros., 1858 : " Just as copper increases 
the hardness of aluminium, so aluminiu'm in small 
proportions increases the hardness of copper. How- 
ever, aluminium does not injure its malleability, 
but makes it susceptible of taking a beautiful 
polish, and, according to the proportions, varies its 
color from red gold to pale yellow. These facts 
were announced some time back by Dr. Percy, in 
England, who made the alloy by introducing 
copper into the mixture of cryolite and sodium 
which he was reducing. We have made large 
quantities of these alloys, and we may say that 
they leave nothing to be desired in regard to lustre 
or color to make them perfect imitations of gold. 
They alter much less by successive fusions than 
the alloys of copper with zinc and tin employed 
for the same object. A ten per cent aluminium 
alloy was harder than our gold coin, took a fine 
polish by burnishing, and had the color of pale 
jeweller's gold ; it could be forged and worked the 
same as copper. The five per cent, aluminium 
alloy was less hard than the preceding, but, like 


it, takes a fine polish, and in tint approaches 
nearly to pure gold. The twenty per cent, alumin- 
ium alloy much resembles bismuth, having a 
whitish-yellow tint. This alloy crystallizes in 
large leaves and pulverizes in the mortar like bis- 
muth or antimony. Alloys with five to ten per 
cent, of aluminium may have their color changed 
at will, either by leaving in nitric acid, which 
takes away the copper and leaves the aluminium, 
or in hydrochloric, which leaves the copper. The 
resistance, hardness, and elasticity, which are 
communicated to copper by introducing small 
quantities of aluminium, will certainly make these 
important industrial alloys." 

Deville, 1859: "The aluminium and copper 
alloys with two to three per cent, aluminium are 
used by M. Christofle, who employs them for large 
castings of objects of art. They are harder than 
aluminium, and work well under the burin and 
chisel. The alloy with ten per cent, aluminium 
had its useful properties first described by M. 
Debray. It is very hard, can be beaten out cold, 
but with remarkable perfection when hot, and may 
be well compared to iron, which it resembles in all 
these physical properties. It is also very ductile. 
This ten per cent, aluminium alloy is usually 
known as aluminium bronze. It behaves as a true 
alloy, and, in consequence, will not liquate into 
different combinations. It is formed of 



9 equivalents of Cu . . . 275 9 

1 " " Al . . . 28 1 

303 10 

This is proven by the fact that, when in making 
the alloy the pure copper is in the crucible and a 
bar of aluminium is added, the combination takes 
place with such disengagement of heat that if the 
crucible is not of good quality it will be fused, for 
the whole becomes white hot. 

" The color of the ingot of bronze is exactly that 
of c green gold,' an alloy of gold and silver. The 
bronze receives a beautiful polish, being comparable 
in this regard only to steel. Its chemical proper- 
ties do not differ much from those of most of the 
allo3 r s of copper. However, in numerous experi- 
ments, we have noticed that it resists most chemical 
agents much better than these, especially sea-water 
and sulphuretted hydrogen. Its tenacity is equal 
to that of steel. M. Lechatelier made the follow- 
ing determinations on the metal cast into cylinders: 

Per cent, of Diarn. of 
aluminium. cylinder. 

10 -10.0m. m. 

Breaking strain. 

4627 kilos. 

Strength per 
sq. m. m. 

58.36 kilos. 


10.1 " 

4432 " 

55.35 " 


10.1 " 

2657 " 

33.18 " 


10.1 " 

2582 " 

32.20 " 


10.1 u 

2517 " 

31.43 " 

French wrought iron . . 35.00 " 

" A. Gordon made some experiments recently, in 
which the strength of the aluminium bronze which 


he tested was 84.00 kilos per square millimetre. 
I made the test on some wire, and the result I 
reached was 85.00 kilos ; under the same condi- 
tions iron gave 60.00 and best steel 90.00 kilos. 
According to experiments as to its wear as journal 
boxes, it is found to wear away less than any other 
journal metal yet tried. 

" Its malleability is almost perfect, as is seen by 
the following report of M. Boudaret, a practical 
engineer: First, aluminium bronze is malleable at 
all temperatures, from bright red to cold ; second, 
it is perfectly malleable at red heat, breaking less 
and elongating more than pure copper ; third, it is 
hard to roll in the cold, after several passes it 
ceases to elongate and must then be annealed very 
often or it will break quickly; fourth, it results 
from the foregoing that it is best to roll it at as 
high a heat as possible below fusion ; fifth, anneal- 
ing and tempering render it softer than simple 
annealing. If after having annealed at bright red 
heat it is let cool in still air to redness arid then 
plunged into cold water, it is ductile and malleable 
enough in the cold to stand all industrial working." 

Mierzinski, 1885: "Two points are to be at- 
tended to in making aluminium bronze. First, a 
very pure copper must be used, the best is that 
electrically deposited, but it generally costs too 
much. The next best is the Lake Superior brand. 
The usual commercial copper gives all sorts of poor 
results, owing to the antimony, arsenic, tin, zinc, 


or iron contaminating it. The bronze loses by being 
alloyed with zinc or tin. Second, the alloy must 
be remelted two or three times to remove its brittle- 
ness. In all probability, the percentage of alu- 
minium increases by remelting. The usual alloys 
are those with 1, 2, 5, and 10 per cent, aluminium. 
The 5 per cent bronze is golden in color, polishes 
well, casts beautifully, is very malleable cold or 
hot, and has great strength, especially after ham- 
mering ; its defect is that it easily oxidizes or 
tarnishes. The 7.5 per cent, bronze is to be recom- 
mended as superior to the 5 per cent. ; it has a 
peculiar greenish-gold color, which makes it very 
suitable for decoration. All these good qualities 
are possessed by the 10 per cent, bronze. It is 
bright golden, keeps its polish in the air, may be 
easily engraved, shows an elasticity much greater 
than steel, and can be soldered with hard solder. 
It gives good castings of all sizes and runs in sand 
moulds very uniformly. Thin castings come out 
very sharp, but if a casting is thin and suddenly 
thickens, small offshoots must be made at the 
thick place into which the rnetal can run and then 
soak back into the casting as it cools and shrinks, 
thus avoiding cavities by shrinkage at the thick 
part. Its sp. gr. is 7.689, that of soft iron. Its 
strength, when cast, is between that of iron and 
steel ; but when hammered it is equal to best steel. 
It may be forged at about the same heat as cast 
steel, and then hammered until it is almost cold 


without breaking or ripping. Tempering makes 
it soft and malleable. It does not foul a file, and 
may be easily drawn into wire. Any part of a 
machine which is usually made of steel can be re- 
placed by this bronze. As a solder for it, Hulot uses 
an alloy of the usual half-and-half lead-tin solder 
with 12.5, 25, or 50 per cent of zinc amalgam." 

Fremy : " By the addition of a small amount of 
copper, aluminium becomes hard, brittle, and takes 
a bluish-white color. The alloy with 5 per cent, 
aluminium is very malleable, but if over 10 per 
cent. Al is present the alloy cannot be used. 
The 10 per cent, bronze is now replacing ordinary 
bronze in the manufacture of articles which are to 
stand great resistance, such as axle bearings, 
weavers' shuttles, etc. Reflectors are also made of it, 
for the smoke of oil, like illuminating gas, does not 
tarnish it. By whatever method these bronzes are 
made, they are at first very brittle, but by a series 
of successive fusions and solidifications they may be 
made to acquire the necessary solidity and tenacity." 

Kerl and Stohman : "Most of the copper-alu- 
minium alloys are very brittle and easily oxidized. 
Only the 5 to 10 per cent, aluminium alloys are 
fixed, forgeable, tenacious, and of fine color. 
Alloys with much aluminium and little copper are 
not forgeable, and are bluish or grayish-white. 
AVith 60 to 70 per cent, aluminium they are very 
brittle, glass hard, and beautifully crystalline. 



With 50 per cent, the alloy is quite soft, but under 
30 per cent, of aluminium the hardness returns." 

4 Chemical News,' vii. p. 220, contains a long 
paper on testing aluminium bronze (10 per cent.) 
as to its suitability for the construction of astro- 
nomical and philosophical instruments, the work 
of an English Royal Engineer. He concludes his 
observations with these words : " It appears from 
these experiments that the 10 per cent, bronze is 
far superior, not in one or in some but in every 
respect, to any metal hitherto used for these instru- 
ments. Its sp. gr. is 7.689, strength 73,185 pounds 
per square inch, to that of gun metal 35,000 ; it is 
malleable almost to its melting point, and can be 
soldered with either brass or silver solder.' 7 

' Chemical News,' v. p. 138, contains a number 
of experiments on the relative strengths of these 
alloys. The results are as follows, the numbers 
expressing the results being merely relative : 

Ordinary gun metal, 11 per cent tin and 

89 per cent, copper . . . . . .10 

Copper, with 10 per cent, aluminium . . .19 
Drawn copper- wire ...... 7 

Drawn brass-wire . . . . . .8 

( Cu Sn Al 

I 96 4 . . . .4 
Tertiary alloys <| 96 4 l ^ _ w 

( 96 4 2 . . . .16 

Bell Bros., Newcastle, give the specific gravity 
of the aluminium bronzes as being 


3 per cent, aluminium . . . 8.091 

4 " " ... 8.621 

5 " " ... 8.369 
10 " " , . 7.689 

' Wagner's Jahresb.' vol. x., contains a long article 
on aluminium bronze, ten per cent., most of the 
facts in which have been already given. We may 
note that the melting-point of this alloy is there 
stated as about 650. 

Bernard S. Procter,* after describing thirty-one 
experiments comparing aluminium bronze and 
brass, sums up the conclusions as follows : 

" From the above experiments it appears that 
aluminium bronze has a little advantage over ordi- 
nary brass in power to withstand corrosion, and its 
surface, when tarnished, is more easily cleaned. 
This should give it general preference where cost 
of material is not an important consideration, es- 
pecially if strength, lightness, and durability are 
at the same time desirable. It is out of my power 
to say anything about its fitness for delicate ma- 
chinery, except that its chemical examination has 
revealed nothing which can detract from the pre- 
ference its mechanical superiority should give it. 
Being so much less acted on by ammonia and coal- 
gas suggests its suitability for chemical scales, 
weights, scoops, etc. Its resistance to the action of 
the weather and the ease with which tarnish is. 
removed render it especially applicable for door- 

* Chem. News, 1861, vol. iv. p. 59. 


plates, bell-handles, etc. Its mechanical strength 
and chemical inactivity together recommend it for 
hinges exposed to the weather. In experiments 18, 
22, etc., the tendency of brass to corrode on the 
edges and at any roughness on its surface will be 
observed, while the bronze is free from this defect. 
In several cases the bronze seemed to be more 
quickly covered with a slight tarnish which did 
not increase perceptibly, probably the tarnish act- 
ing as a protection to the metal ; but the brass, 
though less rapidly discolored, continued to be 
corroded and apparently with increased speed as 
the action was continued. The bronze is more 
easily cleaned. For culinary vessels its superiority 
to metals now in use appears questionable. Vari- 
ous philosophical instruments are among the pur- 
poses for which the use of the bronze appears 
advantageous. Undoubtedly, the great obstacle to 
its extensive application is its high price, resulting 
partly from the difficulty of getting sufficiently 
pure copper, the presence of a small amount of iron 
being very prejudicial." The author states that he 
wrote the article with a home-made pen of alumin- 
ium bronze, and suggests that it is well worthy of 
the attention of pen-makers. 

Thurston* says: "The ten per cent, bronze has 
a tenacity of about 100,000 pounds, compressive 
strength 130,000 pounds, and its ductility and 

* Materials for Engineering. 


toughness are such that it does not even crack 
when distorted by this load. It is so ductile and 
malleable that it can be drawn down under a ham- 
mer to the fineness of a cambric needle. It works 
well, casts well, holds a fine surface under the tool, 
and when exposed to the weather it is in every 
respect considered the best bronze yet known. Its 
high cost alone has prevented its extensive use in 
the arts. The alloys are very uniform in character. 
Even one per cent, of aluminium added to copper 
causes a considerable increase in ductility, increases 
its fusibility, and enables it to cast well ; two per 
cent, gives a mixture used for castings which are 
to be worked with a chisel. It is softened by sud- 
den cooling from a red heat. Its coefficient of ex- 
pansion is small at ordinary temperatures. It has 
great elasticity when made into springs." 
Guettier makes the following remarks : * 
" Mr. Strange's experiments in regard to the 
relative rigidity of brass, ordinary bronze, and alu- 
minium bronze showed that the latter was about 
forty times as rigid as soft brass and three times 
as rigid as ordinary bronze. Under the tool, alumin- 
ium bronze produces long and resisting chips, and 
although not entirely unoxidizable, it is not so 
easily tarnished by air as brass, bronze, or steel." 
Knight :f "Aluminium bronze is more difficult 

* Metallic Alloys, by Guettier. 

f American Mechanical Dictionary. 


to cut than brass, but cuts very smooth and clean. 
If less costly it would replace red and yellow brass. 
In contact with fatty matters or juice of fruit, no 
soluble metallic salt is formed, which highly recom- 
mends it for various articles of table use." 

Cowles Bros.* thus describe the alloys of alumin- 
ium and copper which they make : 

" In England the Aluminium Crown Metal Co. 
has for the past three or four years been turning 
out large quantities of aluminium alloys based on 
the price of $14.60 per pound for the aluminium 
in them. Even at the high prices charged, these 
Webster alloys have attained a great popularity, 
and are replacing German silver, brass, bronze, etc. 
Aluminium added to any of the common alloys, 
such as brass, German silver, or Britannia metal, 
adds greatly to all their desirable qualities. Alu- 
minium bronze cannot only be used in all places 
where brass or bronze are now used, but it will 
likewise soon supersede iron and steel in many 
places; as for artillery. The maximum standard 
of strength demanded by the British and German 
governments in their wrought-steel guns, which 
cost from 50 cents to $1 per pound, is at present 
70,000 pounds tensile strength and 15 per cent, 
elongation. These guns could be cast of aluminium 
bronze, giving a greater strength and elongation, 
at far less cost, being made in one-quarter of the 

* Cowles' Pamphlet, April, 1886. 


time and with a comparatively inexpensive plant. 
The melting-point of the bronze is somewhat below 
that of copper and its specific gravity is 7.23. It 
is without rival as an anti-friction metal, besides 
having the hardness, tenacity, and wearing quali- 
ties of the best steel. It has also the peculiar 
uiictuousness of copper and lead, being so strong 
and tough that very small quantities of the rolled 
bronze may be used to bush boxes of cast or 
wrought iron, so that its first cost is less than that 
of the thick masses of brass or phosphor-bronze 
now used. The five per cent, bronze makes beauti- 
ful wearing plumbers' goods, and can be used also for 
table articles, being free from the offensive smell 
and taste peculiar to brass. Aluminium in almost 
all proportions up to eight per cent, improves all 
brasses. Some it makes more ductile, in others it 
improves the color, and all are greatly increased in 
strength and power to resist corrosion. The alloy 
copper 67, zinc 26, aluminium 7 has a strength of 
96,000 pounds, while that of copper 67, zinc 30, 
aluminium 3 has a strength of 65,000 pounds with 
12 per cent, elongation. When we understand 
that ordinary brass rarely has a tensile strength 
over 30,000 pounds, the extraordinary value of the 
aluminium can be appreciated. The strength of 
these alloys on the testing machine is as follows : 


Alloy, Tensile strength per Elongation, 

Al brass castings. sq. in., pounds. per cent. 

Al Cu Zn 

5.8 67.4 26.8 95,712 1 

3.3 63.3 33.3 85,867 7.6 

3.0 67.0 80.0 67,341 12.5 

1.5 77.5 21.0 32,356 41.7 

1.5 71.0 27.5 41,952 27.0 

1.25 70.0 28.0 35,059 25.0 

2.5 70.0 27.5 40,982 28.0 

1.0 57.0 42.0 68,218 2.0 

1.15 55.8 43.0 69,520 4.0 

Average commercial cast brass 23,000 Less than 10.0 

" The second alloy is made by mixing two parts 
five per cent, aluminium bronze with one part zinc. 

" The aluminium bronzes gave the following 
results : 

Al Cu Tensile strength, Elongation in 

pounds. per cent. 

2.5 97.5 42,770 53 
5.0 95.0 68,480 7.8 

6.6 93.4 55,038 80 
7.5 92.5 54,636 16 
7.5 92.5 60,520 22 

91 9 87,783 5 

90 10 108,966 

90 10 99,931 1.5 

90 10 97,103 3.0 

90 10 105,336 7.8 

90 10 110,657 5.4 

16.8 83.2 29,369 (Sp. gr. 3.23) 

" The two 10 per cent, bronzes last given were 
plunged while red hot into water. Cowles Bros. 


are now selling 10 per cent, bronze at forty cents 
per pound." 

In regard to some alloys of aluminium and 
copper in which other metals are present, we Would 
notice the following alloys which have been made in 
addition to those already incidentally mentioned. 

Aluminium can be melted with brass, argentan, 
etc., by which new bronzes are made of beautiful 
color, great hardness, and polish, unalterable in the 
air, easily cast, etc. One per cent, of aluminium 
is sufficient to modify the qualities of brass or tin 
bronze, while 2 per cent, shows a decided change. 
By taking ordinary bronze with 1 to 2 per cent, of 
zinc or tin, and adding 1 to 2 per cent, of alu- 
minium, alloys are obtained possessing additional 
qualities to those of aluminium bronze, and which 
can replace it in places and for purposes where the 
latter's qualities are not so well suited. 

Besides these simple alloys we have those of 
copper with nickel, tin, zinc, bismuth, and alu- 
minium, in such quantities as to make any desired 
color or degree of hardness. The following has a 
beautiful white polish, which is a close imitation 
of silver : 

Copper . 100 

Nickel 23 

Aluminium 7 

F. H. Sauvage makes a metal resembling pure 
silver, which he calls Neogen. It contains 


Cu . . . . . . . 58 

Zn ....... 27 

Ni ....... 12 

Sn ....... 2 

Al ....... 

" Minargent" is a similar alloy, containing 

Cu ....... 100 

Ni ....... 70 

Sb ....... 5 

Al ...... .2 

To make this last alloy, the directions are first to 
melt together the copper, nickel, and antimony, 
and then granulate the resulting alloy in water. 
The dried granules are mixed with the aluminium 
and with 1.5 per cent, of a flux consisting of 2 parts 
horax and 1 part fluorspar, and then remelted. 

P. Baudrin makes an alloy very much resembling 
silver in color, malleability, ring, and even sp. gr., 
of the following composition : 

Cu ....... 75 

Ni ....... 16 

Zn ....... 2.25 

Sn ....... 2.75 

Co ....... 2 

Fe .... 1.5 

Al ....... 0.5 

Jas. Webster* patents the following bronze: 
copper is melted, and aluminium added so as to 

* German Pat., 11,577. 


make a 10 per cent, bronze, which is then mixed 
with 1 to 6 per cent, of an alloy of 

Cu 20 

Ni 20 

Sn 30 

Al 7 

Thos. Shaw, of Newark, N. J.,* pa tents a phosphor 
aluminium bronze, making the following claims: 
First, an alloy of copper, aluminium, and phos- 
phorus containing 0.83 to 5 per cent, of aluminium, 
0.05 to 1 per cent, of phosphorus, and the remainder 
copper. Second, its manufacture by melting a bath 
of copper, adding to it aluminium in the proportion 
stated, the bath being covered with a layer of palm 
oil to prevent oxidation, and then adding a small 
proportion of phosphorus. 

Cowles Bros, in their pamphlet give the follow- 
ing tests of the strength of aluminium-silver cast- 

Tensile strength, Elongation, 

pounds. per cent. 

5 p. ct. Al broiize, 1 part ; Ni 2 parts 79,163 33.0 

" 4 parts ; Ni 1 part 118,000 

German silver without aluminium 44,242 24.0 

" " with " 92,849 1.0 

Solders for Al Bronze. Cowles give the follow- 
ing jeweller's solder for aluminium bronze: 

* U. 8. Pat., 303,236. Aug. 1884. 


Hard solder for 10 per cent, bronze 

Au ....... 88.88 

Ag ....... 4.68 

Cu ....... 6.44 

Middling hard solder for 10 per cent, bronze 

Au ....... 54.40 

Ag ....... 27.00 

Cu . . ..... 18.00 

Soft solder for Al bronze 

Au .... 14.30 
Ag .... 57.10 
Cu .... 14.30 

Silicon and Aluminium Bronze. Cowles Bros. 
have, by reducing fire clay in presence of copper, 
obtained alloys of aluminium, silicon, and copper. 
This alloy is white and brittle if it contains over 
10 per cent, of aluminium and silicon together. 
With from 2 to 6 per cent, of these in equal pro- 
portions, the alloy is stronger than gun metal, is 
very tough, does not oxidize when heated in the 
air, and has a fine color. Cowles report that a 
silicon-aluminium bronze wire has shown a tensile 
strength of 200,000 pounds, a strength hitherto 
unprecedented in any metal. 


Tissier Bros., 1858 : " An alloy of aluminium 
and iron with 5 per cent, iron was made by 


placing very fine iron wire with fragments of alu- 
minium in a crucible containing melted XaCl. 
Under these circumstances the iron could not oxi- 
dize, and the alloy was easily formed. We have 
in this way been able to discover that small quan- 
tities of iron give to aluminium the property of 
crystallizing, and much impair its malleability. 
When aluminium has become low in price, it will 
be interesting to see what qualities it can com- 
municate to iron as cast iron or steel, introduced 
in large or small quantities. Iron raises the fusing 
point of the aluminium, for we have melted alu- 
minium free from iron on a plate of aluminium 
containing 4 to 5 per cent. iron. 

Deville, 1859 : . " Iron and aluminium combine 
in all proportions. These alloys are hard, brittle, 
and crystallize in long needles, when the propor- 
tion of iron reaches 7 or 8 per cent. The alloy 
containing 10 per cent, iron much resembles sul- 
phide of antimony. It liquates, however, with 
some facility, leaving a less fusible skeleton, while 
less ferruginous aluminium runs down. But this 
method of purifying aluminium is not exact. The 
presence of a large quantity of iron in aluminium 
alters both its chemical and physical properties." 

Rogers :* " By melting a steel high in carbon 
with aluminium, alloys of steel and aluminium 
may be obtained. I have one containing 6.4 per 

* Moniteur Industrie!, 1859, No. 2379. 



cent, of the latter. I melted 67 parts of this alloy 
with 500 of steel, so that the resulting steel con- 
tained 0.8 per cent, aluminium. This metal had 
the qualities of the best Bombay wootz. A small 
per cent, of aluminium makes steel hard, strong, 
and brittle, a larger quantity makes it very dense, 
without impairing its peculiar polish or detracting 
from its qualities." 

Fremy, 1883: "Aluminium unites with iron 
with the greatest facility. To form an alloy it is 
sufficient to stir a rod of iron in melted aluminium, 
when it covers itself with a layer of aluminium 
and takes on the aspect of being amalgamated. 
The alloy with 5 per cent, iron is hard, brittle, 
and more difficult to fuse than aluminium. The 
7 per cent, iron alloy possesses the same proper- 
ties, with a crystalline structure. The 10 per 
cent, iron alloy, according to Deville, resembles 
sulphide of antimony, Sb 2 S 3 . On the other hand, 
M. Debray affirms that 7 to 9 per cent, of 
iron in aluminium causes no appreciable change in 
its properties. By melting ten parts aluminium, 
five parts ferric chloride, and twenty parts KC1 
and !NaCl, Michel obtained on cooling a mass 
which, treated with very dilute sulphuric acid, 
left six-sided prisms having the color of iron and 
the formula Al 2 Fe, containing 51 per cent. Fe.* 
Calvert and Johnson obtained the alloy Al 2 Fe 3 , 

* Ann. Cheni. und Pharm. 115, 102. 


containing twenty-four per cent, aluminium and 
seventy-six per cent, iron, which was unalterable 
in moist air (see p. 210). The alloy AlFe 4 , con- 
taining 10.8 per cent, aluminium, has been pre- 
pared by melting two parts aluminium, five parts 
sheet iron, and one part of chalk. It is easily 
worked and rolled, but rusts on contact with the 

Mierzinski : " A few per cent, of aluminium is 
useful in making cast steel, to which it imparts 
greater hardness and a bright silver-like polish ; 
0.8 per cent, aluminium gives steel all the qualities 
of best Bombay wootz, and objects made of it, 
treated with dilute sulphuric acid, give the undu- 
lating markings generally found only on Damascus 
steel. Stoddart and Faraday found in wootz 
steel 0.013 to 0.690 per cent, of aluminium. An 
alloy of 24.5 per cent, aluminium is silver white, 
extraordinarily hard, and does not rust in the air. 

Mitis castings :* " The subject of the use of alu- 
minium in wrought-iron castings was discussed at 
the meeting of the American Society of Mining 
Engineers, Pittsburgh meeting, on Feb. 16. It 
was described by the inventor, Mr. Peter Ostberg, 
of Stockholm, and as his paper has not yet appeared 
we give a few particulars which may be of interest. 

u Wrought-iron scrap is melted in plumbago 
crucibles in a special reverberatory furnace fired 

* Eng. and Mining Journal, Feb. 27, 1886. 


with petroleum. The crucible is covered, while a 
'hole in a cover corresponds with and is directly 
under a hole in the roof of the furnace. Wrought 
iron fuses at about 4000 F., and it would be neces- 
sary to heat it far beyond its point of fusion before 
it would be fluid enough to cast into line moulds 
and to make it possible to handle it before it would 
solidify. Now it is in this superheating that the 
iron absorbs gases, and consequently it is impossible 
to make solid castings in this way. In order to 
obviate this difficulty, Mr. Ostberg has made use 
of the well-known fact that certain alloys of metals 
possess a fusing point much less than that of the 
metals composing them, among which aluminium 
alloys are very noticeable. In making w rough t- 
iron or mitis castings a very small quantity of alu- 
minium, about 0.05 per cent., is added to the charge 
in the crucible the moment it has been melted. 
The charge is about sixty pounds. The aluminium 
is added in the form of an iron-aluminium alloy 
containing 7 to 8 per cent, of aluminium. The 
fusing point of the whole is at once lowered 
some 500 degrees, and the charge being then 
nearly 500 degrees above its new .fusing point be- 
comes extremely fluid and can be cast into the 
finest moulds ; while the great difference between 
its temperature and its reduced fusing point gives 
all the time necessary for manipulating it without 
danger of solidifying. This extreme fluidity 
allows the ready escape of gases which would 


otherwise make the casting porous, and the result 
appears to be a remarkably fine, solid, and tough 
casting of wrought iron. 

" These mitis castings are said to be 30 to 
50 per cent, stronger than the iron from which 
they are made; but, although aluminium undoubt- 
edly increases the strength of most metals with 
which it alloys, it is not credited with the increase 
of strength in this case ; for it is said that after 
hammering, the mitis metal loses its increase in 
strength and returns to the fibrous appearance and 
strength of the original iron. 

" The alloys of iron and steel with aluminium 
have long been known, and reference is made to 
the addition of such an alloy to steel by Faraday, 
only a few years after the discovery of aluminium ; 
but this application to wrought iron castings 
appears to be new and is certainly very interest- 

" The alloy used by Mr. Ostberg at his works in 
"Worcester, Mass., is made by the Cowles Electric 
Smelting Co., and contains 6 to 8 per cent, 
aluminium and 1 to 1.25 per cent, of silicon. It 
costs about fort} T cents per pound, but as only 0.05 
per cent, aluminium is required in the iron, 
the addition to its cost is very slight. This utili- 
zation of the well-known property of aluminium 
to lower the fusing point of the iron is a very neat 
and clever application of a curious phenomenon, 
and it is said to succeed very well. Whether it. 


will also facilitate the making of small steel cast- 
ings is not stated, but it would probably in this 
case make the metal more fluid and obviate the 
necessity of using those extremely high heats 
which are necessary to cause the steel to melt and 
run well into the moulds." 

Mr. Ostberg sent a note to the ' Engineering and 
Mining Journal/ stating that he used only a small 
sample of Cowles' alloys, but that he uses almost 
altogether a 7 to 8 per cent, aluminium alloy, 
made in Sweden by a very simple and cheap 
patented process, which consists in adding clays in 
iron smelting. 

The following note, bearing on this subject, is 
from Watts: "The 'London Mining Journal' 
states that if common kaolin is added to iron when 
being smelted in a crucible to convert it into steel, 
an improved product is the result." Aside from 
this note, the author has been unable to find any 
reference to the process suggested by Mr. Ostberg. 

Mr. Sellers, of Philadelphia, remarked after the 
reading of Dr. Hunt's paper on the Cowles furnace 
at the Washington meeting of the National Acad- 
emy of Sciences, April, 1886 (see p. 196), that he 
had made a series of experiments on the use of 
aluminium with iron in casting, and obtained 
what is technically called a " dead melt" in two or 
three minutes, instead of an hour as required by 
previous methods. The result is very fine castings, 


and without the flaws which so often vex the 

A company has been incorporated in New Jersey 
within the last month to regulate the use and sell 
rights to use Mr. Ostberg's patents. Mr. Fritz, of 
the Bethlehem Iron Works, is one of the heads of 
the company, which includes other prominent 
Bethlehem capitalists. 


Tissier Bros., 1858: "An alloy with 10 per 
cent, aluminium is brittle, has the appearance of 
zinc, is more fusible than aluminium, and less 
so than zinc. An alloy with 25 per cent, 
aluminium has a tine even grain, and is still more 
fusible than aluminium and less so than zinc. An 
alloy with 50 per cent, did not appear to be 
homogeneous ; heated on an aluminium plate it 
separated into a fusible portion and a part which 
did not melt till the plate did. These alloys have 
been tried as solders for aluminium, and so far 
have succeeded better than any other alloys, but, 
unfortunately, when, melted they are thick and 
cast with difficulty, so much so that it is necessary 
to spread them over the joint as a plumber does 
when he wipes the joints of lead pipes. Joints 
thus made stand hammer blows or rough usage 
very poorly." 

Deville, 1859 : " The alloys of aluminium and 


zinc are brittle, at least unless the zinc is in small 
proportion. Several specimens of zinciferous alu- 
minium were put into commerce by a singular 
accident ; the retorts used for making the alumin- 
ium were made at the Vielle Montague Zinc Works, 
and having in their mixture some ground-up old 
zinc retorts, the new retorts contained zinc, which 
got into the aluminium and altered its properties 
in a very evident manner. Some analyses of this 
metal having been made in England, some asserted 
that French aluminium was only an alloy to which 
zinc gave a fusibility which might be wanting in 
pure aluminium. The alloys of zinc and alumin- 
ium have been used in experiments to solder alu- 
minium solidly, but so far with little success. 
Zinc unites easily with the aluminium, altering its 
properties when exceeding a few per cent." 

Kerl and Stohman, 1874 : " Zinc and alumin- 
ium melted together in atomic proportions under 
a cover of Nad and KC1 unite with incandescence, 
forming a silver-white, very brittle, crystalline alloy, 
with a specific gravity of 4.532." 

Fremy, 1883: "The alloys of zinc and alu- 
minium are employed to solder aluminium. They 
will take a very fine polish. The alloy with three 
per cent, zinc is yet malleable, but that with thirty 
per cent, aluminium is white, crystalline, and very 



Tissier Bros., 1858 : An alloy with 3 per cent, 
tin is very brittle, a little more fusible than 
aluminium. It was made by combining the metals 
under a cover of NaCl, then remelted alone, and 
cast. Its grain is very fine and crossed, and it 
breaks at the first blow of the hammer. If tin, 
even in small quantities, injures the qualities of 
aluminium, the latter, on the contrary, gives to tin 
hardness and tenacity, if it is not present in too 
large an amount. The alloy with 5 per cent, 
aluminium possesses these desirable qualities. The 
alloy with 10 per cent, is not homogeneous, for it 
arranges itself in the ingot in two layers, an upper 
brittle one, a little more fusible than aluminium, 
another lower one containing nearly all the tin but 
rendered harder and less fusible by a small quan- 
tity of aluminium. These alloj^s have been used 
to solder aluminium because of their fusibility and 
the ease with which they adhere to a clean surface, 
but they have the same inconveniences as the zinc 
solders, tney run thick and are fragile. 

Deville : Tin unites easily with aluminium, 
altering its properties as soon as the proportion 
has passed a few per cent. These alloys may be 
used to solder aluminium, but they answer imper- 

Kerl and Stohman : The aluminium-tin alloys 
with over 30 per cent, of the former are silver- 



white, but porous and brittle. The 19 per cent. 
and especially the 7 per cent, aluminium alloys 
are, on the contrary, malleable and workable at a 
red heat. 

Fremy : A small quantity of tin renders alu- 
minium brittle, but a small percent, of aluminium 
alloyed with tin renders it harder and more elastic. 
Such an alloy, besides being easy to work, may 
advantageously replace tin in many of its uses. 
The alloys most recommended are those with 5, 7, 
and 19 per cent, of aluminium. 

Mierzinski: Aluminium and tin unite in cer- 
tain proportions, but the tin will not combine with 
more than 7 per cent, of aluminium, for the 10 
per cent, aluminium alloy is no longer homogeneous 
but on cooling liquates away a more fusible and 
leaves a less fusible alloy, the latter being richer 
in tin. An alloy with 3 per cent, aluminium is 
harder than tin and less acted on by acids. The 
7 per cent, aluminium alloy is especially recom- 
mended as being easy to work, capable of being 
polished, but possessing the drawback that it can- 
not be melted without a part of the tin separating 
from the aluminium. 

M. Bourbouze,* a French physicist, employs an 
alloy of aluminium and tin for the interior parts 
of optical instruments, in place of brass. The 
alloy contains 9 per cent, of tin. It is white, like 

* Iron Age, July 29, 1886. 


aluminium, and has a density of 2.85. This light- 
ness is of great advantage. It can be soldered as 
easily as brass, without special apparatus, and is 
more resistant to reagents than aluminium. It 
would be very useful for electrical instruments, 
especially those of a portable character. 


Tissier: As Deville has remarked, these two 
metals have such little tendency to combine that 
there may be recovered intact in the bottom of an 
ingot of aluminium any small pieces of lead which 
may accidentally have got into the metal. 

Deville: Lead unites only imperfectly with 
aluminium. However, an alloy may exist in cer- 
tain proportions, especially at the temperature 
necessary to the cupellatiou of aluminium. The 
cupellation of aluminium with lead is quite pos- 

Kerl and Stohman : Aluminium does not unite 
with lead. 

Mierzinski : Aluminium and lead do not unite. 
By melting the metals together and cooling down, 
they are found separated from each other, the 
aluminium above and the lead beneath. This 
property suggests the possibility of using it to 
separate silver from work lead, as soon as its price 



Tissier: Aluminium also appears to have as 
little tendency to unite with antimony as with 
lead ; we did not succeed in getting a homoge- 
neous alloy of the two metals. 

Kerl and Stohman : Aluminium does not unite 
with antimony. 


Tissier : The combination of these two metals 
takes place easily and gives rise to very fusible 
alloys, which oxidize very rapidly when melted. 
They are also very alterable in the air at ordinary 
temperatures when the bismuth is in large per 
cent. However, these metals do not appear able 
to unite in all proportions, as the following experi- 
ment seems to prove. We melted together 10 
grms. aluminium and 20 grms. bismuth. The 
combination took place under NaCl, and although 
it was stirred carefully the button appeared to be 
of two layers, the lower one composed of almost 
pure bismuth, and the upper one more malleable, 
detachable from the lower by a blow of the 
hammer, and weighing 13.45 grms. Supposing 
that this latter contained all the aluminium (there 
appeared to be none in the other layer), then the 
alloy was composed of nearly 75 per cent, alumin- 
ium and 25 per cent, bismuth. Thus the aluminium 
did not appear able to take up over 25 per cent, of 


bismuth. The alloy containing 10 per cent, bis- 
muth is hard, malleable, takes a fine polish, is 
unattaoked by nitric acid, and not blackened by 
sulphuretted hydrogren. We say it was malleable 
because it could be worked to a certain extent under 
the hammer, and we thought it could be easily 
drawn out, but in spite of frequent annealings it 
split in all directions and we had to stop working 
it. We tried, by diminishing the per cent, of 
bismuth, to take away this bad quality, and to 
this end prepared alloys with 5, 3, 2.5, and 0.5 per 
cent, of the latter, but without obtaining satisfac- 
tory results. 

Watts : One-tenth of one per cent, of bismuth 
renders aluminium so brittle that it cracks under 
the hammer after being repeatedly annealed. 


Tissier: The alloy with 50 per cent, nickel was 
made by melting together the metals in equal pro- 
portions under XuCl ; the heat evolved was suffi- 
cient to raise the mass to incandescence. This alloy 
remained pasty at the temperature of melting 
copper. It is so brittle that it pulverizes under 
the hammer. By melting proper proportions of 
this alloy with more aluminium, an alloy with 25 
per cent, nickel was produced. This is less fusible 
than aluminium, and as brittle as the 50 per cent, 
alloy. By melting some 25 per cent, nickel alloy 



with aluminium, a 5 per cent, nickel alloy was 
obtained. This is much less brittle than the pre- 
ceding, but is still very far from being easy to 
work. From the 5 per cent, alloy one with 3 per 
cent, was made. With this amount of nickel the 
aluminium acquired much hardness and rigidity, 
and was easy to work. A curious fact with this 
alloy is that it may be melted on a plate of alu- 
minium, showing its fusion point to be less than 
that of pure aluminium, the reverse effect to what 
iron produces, which if present in the same pro- 
portion would diminish the fusibility of the 
aluminium. To sum up, the action of nickel on 
aluminium is much analogous to that of iron, for 
nickel, like iron, produces crystalline alloys with 
aluminium, and if employed with care gives to it 
certain desirable qualities such as hardness, elas- 
ticity, etc. 

Mierzinski : To alloy aluminium with nickel a 
certain limiting quantity of nickel must not be 
exceeded. When the latter is present less than 3 
per cent., it behaves similarly to iron in improving 
the qualities of the aluminium in many ways, 
especially in hardness and elasticity. More than 
3 per cent, makes the aluminium brittle and un- 

Argentan has a beautiful color, and takes a high 
polish, it contains 

Cu 70 

Ni 23 

Al . 7 


Minargent contains 

Cu . 

Ni . 

Sb . . 

Al . 






Tissier: Silver is the metal which seems most 
useful in improving aluminium. Five per cent, 
silver gives to aluminium elasticity which is want- 
ing in pure aluminium, increases its hardness and 
its capability of being polished, and does not injure 
its malleability. We have sold a quantity of these 
alloys, the properties of which we will describe. 
All the alloys up to 50 per. cent of silver are more 
fusible than aluminium, the fusibility increasing 
with the amount of silver. The alloy with 33 per 
cent, silver is fusible enough to serve for a solder ; 
but, like the alloys of aluminium with zinc and 
tin, it casts with difficulty and makes a brittle 
joint. With 10 per cent, silver the aluminium 
will not stand under the hammer. The 50 per 
cent, alloy breaks like those of copper. The pres- 
ence of silver in aluminium can always be recog- 
nized by the action of the alloy on a moderately 
concentrated solution of caustic potash. Alumin- 
ium whitens in this solution, but, if it contains 
silver, this being exposed by the dissolving away 
of the aluminium gives the surface a black color. 
By introducing 5 per cent, of aluminium into silver 


the latter acquires the hardness of silver coin, the 
alloy takes a beautiful polish, does not contain as 
alterable a metal as copper, and contains 95 per 
cent, of silver instead of 90. This alloy is easily 
distinguished from the alloy into which copper 
enters by the test with nitric acid, which whitens 
instead of blackening it. 

Deville: A few per cent, of silver will take 
away from aluminium all its malleability. How- 
ever, the alloy with 3 per cent, is used by M. 
Christofle for casting objects of art ; and the alloy 
with 5 per cent, to make knife blades, and it may 
be worked like pure aluminium. It has, moreover, 
the color and lustre of silver, and is not tarnished 
by sulphuretted hydrogen. 

Kerl and Stohman : According to Hirzel, the 
alloy containing 20 per cent, aluminium is very 
porous, silver-white, tarnishing in the air, sp. gr. 
6.733. AlAg 2 , containing 11.11 per cent, alumin- 
ium is also silver-white, a little porous, tarnishes 
in the air, sp. gr. 8.744. AlAg 4 , containing 5.9 per 
cent, aluminium is pure silver-white, very malle- 
able, forgeable, tarnishing in the air, sp. gr. 9.376. 

Fremy : The alloys of aluminium and silver are 
easy to form by direct fusion of the two metals ; 
their hardness is generally superior to that of 
aluminium, but, nevertheless, they are quite as easy 
to work, and in some cases more fusible than it. 
Debray states that the 50 per cent, alloy is as hard 
as bronze. 


Mierzinski : Five per cent, of silver makes alu- 
minium elastic and as hard as coin silver, but not 
brittle. Tbis alloy is workable like pure alumin- 
ium, takes a fine polisb, is light, not magnetic, 
does not rust, and has the color of pure silver, 
whose place it can take for many purposes. How- 
ever, the assertion that this or any other alloy of 
silver and aluminium is not attacked by hydrogen 
sulphide is incorrect and untenable, since, according 
to careful experiments, these alloys are attacked 
quicker and more actively by it than pure silver. 
This alloy is used for watch-springs, dessert-spoons, 
etc., on account of its hardness and elasticity. The 
alloy with 3 per cent, silver has a very fine silver 
color. The 50 per cent, alloy is as hard as bronze, 
but so brittle that it cannot be pressed ; all the 
alloys with over 10 per cent, silver up to the 50 per 
cent, alloy are brittle and cannot be worked with a 

" Tiers Argent" is an alloy of two-thirds alumin- 
ium and one-third silver, which was made homo- 
geneous at first with some difficulty but is now 
easily made. Spoons, forks, and salvers of this 
alloy leave nothing to be desired. It possesses a 
hardness superior to silver, and can be easily en- 

Cowles Bros, state that what is generally known 
and sold as aluminium silver is an alloy of alu- 

* Cbem. News, xvi. 289. 


minium, nickel, and copper; or, in effect, it is alu- 
minium added to German silver. The great 
advantage of this metal is that it will keep its 
beautiful white lustre for all time, and permits of 
objects being made from it in an enduring and sub- 
stantial manner. It requires no plating of any kind. 


Tissier : Aluminium endures a large quantity of 
gold without its ductility being impaired. We have 
prepared an alloy with 10 per cent, of gold which 
works at a red heat as well as aluminium, is a little 
harder but scarcely polishes any better than it. Its 
color, for some cause, is darkish brown, like that 
of tin lightly sulphurized. The alloy containing 
15 per cent, gold can no longer be forged. As to 
the effect of small quantities of aluminium on gold, 
5 per cent, of it gives to the latter a white color 
and makes it brittle as glass. 

Fremy : The alloy with one percent, aluminium 
possesses the color of " green gold ;" it is very hard 
but yet malleable. The alloy with 10 per cent, 
aluminium is white, crystalline, and brittle; the 
alloy with 5 per cent, is brittle as glass. 

Mierzinski : Aluminium can take up as much as 
10 per cent, of gold without its malleability de- 
creasing. This alloy can be forged, but not well 
polished. The color of the gold has entirely dis- 
appeared, seeming to have no effect on the alumin- 



Tissier : Aluminium unites with platinum with 
great ease, forming with it alloys more or less fusi- 
ble according to the proportions of aluminium. 
Five per cent, of platinum makes an alloy not mal- 
leable enough to be worked ; it is probable that by 
diminishing the amount of platinum a suitable 
alloy might be produced. In color it approaches 
that of gold containing 5 per cent of silver. 


Deville : Cadmium unites easily with alumin- 
ium. The alloys are all malleable and fusible, and 
may be used to solder aluminium, though imper- 


Deville: "By melting aluminium with borax, 
boracic acid, or fluo-borate of potassa, an alloy 
very rich in boron was obtained. This alloy, like 
siliceous aluminium, possesses the singular prop- 
erty that the boron diminishes all its useful qualities. 
The alloy is very white, only able to bear slight 
bending, and tears under the rolls. It exhales a 
very strong odor of hydrogen silicide, SiH 4 , with- 
out doubt due to the silica of the vessel which was 
attacked at the same time as the borax. M. 


Wohler and I have shown that the boron may be 
extracted from this alloy in two different forms, 
the graphitoidal and the diamantine boron." De- 
ville gives at the end of his volume on aluminium 
the mode of preparation of this diamantine boron. 


Deville : I was not able, by any effort I made, 
to combine carbon with aluminium. On decom- 
posing carbon tetrachloride, CC1 4 , by aluminium, 
there is formed ordinary carbon, while the alumin- 
ium which remains has undergone no change. 

Cowles: Specimens of alloys of aluminium and 
carbon, yellow and crystalline, have been exhibited, 
which were made in the Cowles furnace. (See 
p. 195.) 


Watts : Lecoq de Boisbaudran makes the fol- 
lowing remarks : " If the proportion of aluminium 
is to be considerable, the two metals are melted 
together at dull redness. The alloys thus obtained 
remain brilliant, arid do not sensibly absorb the 
oxygen of the air in their preparation. After 
cooling they are solid but brittle, even when the 
excess of aluminium has raised the melting point 
to incipient redness. They decompose water iu 
the cold, but better at 40, with rise of tempera- 


ture, evolution of hydrogen, and formation of a 
chocolate-brown powder, which is ultimately re- 
solved into white flakes of alumina." 


"Wohler* fused in a clay crucible 10 grms. of 
titanic acid, 30 grms. cryolite, 15 grms. each of 
Nad and KC1, and 5 grms. of aluminium. This 
was kept at the melting point of silver for one 
hour and then opened. The aluminium had 
become lammelar, and when dissolved in caustic 
soda left a quantity of brilliant, crystalline plates, 
found to be a compound of aluminium, titanium, 
and silicon. The elements of the compound appear 
to be able to unite in various proportions. Its 
density was 3.3. It was infusible before the blow- 
pipe, but heated to redness in chlorine it burnt, 
giving chlorides of the three metals present. 
Another experiment, heated only to the melting 
point of nickel, gave a white compound richer in 
silicon, sp. gr. 2.7. 

Alloysf of aluminium with wolfram, molybde- 
num, and manganese were made by Michel in 
Wohler's laboratory, on which the following report 
is made : 

* Chcm. News, 1860, p. 310. 
t Ibid. 



A1 4 W was made by fusing together 15 grms. 
tungstic acid, 30 grms. cryolite, 15 grms. each of 
KC1 and ]N"aCl, and 15 grms. aluminium, at a strong 
red heat. The excess of aluminium was removed 
from the regulus by HC1. The alloy is an iron- 
gray powder, crystalline, single crystals were 
several millimetres long, brittle and hard rhombic 
prisms. Sp. gr. 5.58. Hot caustic soda extracts 
all the aluminium from these crystals, leaving 
behind pure tungsten. 


Molybdic acetate is dissolved in hydrofluoric 
acid, the solution evaporated to dry ness, and the 
.residue mixed with cryolite, flux, and alumin- 
ium, in the same proportions as given for tungsten. 
Excess of aluminium is dissolved from the product 
with caustic soda, and there remains a black, 
crystalline powder consisting of iron-gray rhombic 
prisms, soluble in hot nitric or hydrochloric acid, 
and consisting entirely of aluminium and molyb- 


We fused together 10 grms. anhydrous manganese 
chloride, 15 grms. each of KC1 and NaCl, and 15 


grms. aluminium. The excess of aluminium was 
removed by HC1. There remained a dark-gray, 
crystalline powder consisting of square prisms, spe- 
cific gravity 3.4. Dilute caustic soda extracts all 
the aluminium from these, leaving the manganese. 


Deville : Aluminium unites easily with sodium, 
especially in small proportions. From this it fol- 
lows that the properties of the metal made care- 
lessly by using sodium are completely altered. 
The last traces of sodium can be removed only with 
great trouble, especially when the aluminium has 
been produced in presence of fluorides, because of 
the marked affinity of aluminium for fluorine at 
the temperature at which aluminium fluoride, 
A1 2 F 6 , commences to volatilize. 

Fremy: Aluminium easily combines with so- 
dium. If the combination contains 2 per cent, of 
sodium, it easily decomposes water, which circum- 
stance gave cause to the notable loss of aluminium 
when it was first being manufactured. 


Dr. Hunt,* in reading a paper on the Cowles 
furnace (see p. 196), showed a specimen of a pecu- 
liar alloy believed to consist entirely of aluminium 
and nitrogen. 

* Washington Meeting, Nat. Acad. Sciences, April, 1886. 



IN the summer of 1884, a large deposit of rock called 
" native alum" was discovered on the Gila River, Sorocco 
Co., New Mexico, about two miles below the fork of the 
Little Gila and four miles below the Gila Hot Springs. 
The deposit is said to extend over an area one mile square 
and to be very thick in places. The greater part of the 
mineral is impure, as is usual with native occurrences, but 
it is thought that large quantities are available. A com- 
pany formed in Sorocco has taken up the alum-bearing 
ground. Through the kindness of Mr. W. B. Spear, of 
Philadelphia, I was enabled to get a specimen of it. 

It is white, with a yellowish tinge. On examining 
closely it is seen to consist of layers of white, pure-looking 
material arranged with a fibrous appearance at right 
angles to the lamination. These layers are about one- 
quarter of an inch thick. Separating them are thin layers 
of a material which is deeper yellow, harder and more 
compact. The whole lump breaks easily and has a strong 
alum taste. On investigation, the fibrous material was 
found to be hydrated sulphate of alumina, the harder 
material sulphate of lime. 

It is probable that this deposit was the bed of a shallow 


lake in which the alum-bearing water from the hot springs 
concentrated and deposited the sulphate of alumina. 
Periodically, or during freshets, the Little Gila, flowing 
through a limestone country, bore into this lake water 
containing lime, which, meeting the A1 2 (S0 4 ) 3 solution, 
immediately caused a deposit of CaSO*. When the dry 
season came, the Little Gila dried up, the deposit of alum 
was made, and thus were formed the succession of layers 
through the deposit. 

Analysis showed 7 to 8 per cent, insoluble material, 
and the remainder A1 2 (SO 4 ) 3 .18H 2 O. A small amount of 
iron was present. 


According to a patent given to F. Lauterborn (see p. 
206), cryolite can be decomposed by boiling with water ; 
sodium fluoride going into solution arid aluminium fluor- 
ide remaining as residue. 

To test the accuracy of this statement, I boiled 250 
grms. of the mineral in 5 litres of water for 3 hours. The 
solution was filtered hot and evaporated to dryness. 
There was no residue. The material on the filter ap- 
peared to be undecomposed cryolite. 

The experiment does not prove that the decomposition 
is impossible, but makes it appear extremely improbable. 


I bought some of Mr. Frishmuth's aluminium from 
Bullock & Crenshaw, Philadelphia. The surface was 
slightly whitened by oxidation, resembling, though not 


to such a degree, the oxidation which takes place on slabs 
of zinc when exposed to the air. The wire was not per- 
fectly smooth, being at places slightly rough and scaly. 
It was quite soft and malleable. Its color was nearly white, 
but with a slight blue tinge, which, if intensified, would 
have made it resemble zinc more than any other metal. 
Duplicate analyses of it gave me the following results : 

Si 0.65 0.56 

Fe 1.94 1.87 

Al (by diff.) . . . 97.41 97.57 

After making these analyses, I came across the analysis 
of Mr. Frishmuth's metal given on p. 53. 


The sp. gr. of the metal whose analysis was just given 
I determined very accurately on a Becker balance. Com- 
pared with water at 4 C., it was 2.735. I wished to see 
if this would correspond to the sp. gr. calculated from the 
analysis. The data were as follows : 

Si . 
Fe . 
Al . 

Calculated sp. gr 2.757 

The correspondence being so close has suggested that 
the sp. gr. of commercial aluminium, carefully taken, gives 
the approximate amount of iron present ; for the sp. gr. 
of silicon is so near to that of aluminium, that 10 per 
cent, of the former, an amount never found in commercial 
aluminium at present, would only affect the sp. gr. 0.03. 

sp. gr. 

Average per 
cent, present. 









So then, within the limits usually found in commercial 
aluminium, i. e., silicon less than 5 per cent, and iron 
anywhere less than 10 per cent., a careful determination 
of the sp. gr. should, hy a little calculation, give the amount 
of iron present within a limit of error of 0.5 per cent, at 
most, thus saving a wet determination of iron. 


Wishing to observe the effect of mercury on metallic 
aluminium, I took a clean, bright piece of aluminium foil 
of Mr. Frishmuth's make, and put on it a small globule 
of mercury, which I rubbed in with the finger. Almost 
immediately a white powder appeared and the foil felt 
warm from the heat generated. On brushing away this 
powder, the foil underneath appeared white and unattacked. 
By letting the mercury remain on the foil, it very soon 
eat a hole through it. Compare with p. 261. 

It thus appears that mercury unites with a clean sur- 
face of aluminium, forming an amalgam, and the alumin- 
ium in the amalgam oxidizes in the air to alumina. The 
question arises, why does aluminium oxidize so easily ? 
We know how the properties of this metal depend much 
on its state of division ; its foil will burn in the air, where- 
as the metal in bulk will not. The mercury serves, as it 
amalgamates the aluminium, to draw apart even the mole- 
cules of the metal, and so this extremely minute, even 
molecular division of the aluminium permits it to exhibit 
in an intensified degree the principle just stated, which 
was illustrated by the burning of the foil, t. e., the finer its 
state of division the more easily is it acted on by oxidiz- 
ing agents. Translating this into the language of chemi- 
cal affinities, in metallic aluminium the atoms are united 


two by two by a mutual exchange of affinities, and the 
oxygen of the air is not able to break this molecular bond 
at ordinary temperatures. But by the intervention of 
the mercury this bond is broken, and the atoms of alu- 
minium become united with atoms of mercury, which 
weakens the bond holding the molecule together. The 
strong affinity which oxygen has for aluminium is now 
able to break up the new molecule, the metal is rapidly 
oxidized and the mercury set free. 


I experimented on reducing alumina by carbon in pres- 
ence of copper. (See p. 213.) I took for a charge 

40 grms CuO and Cu. 

5 " . . . . A12O 3 . 

5 " . . . . Charcoal. 

These were intimately mixed and finely powdered, put in a 
white-clay crucible and covered with cryolite. The whole 
was slowly heated to bright redness, and kept there for two 
hours. A bright button was found at the bottom of the 
crucible. This button was of the same sp. gr. as pure 
copper, and a qualitative test showed no trace of aluminium 
in it. 

This is the same result that other experimenters have 
reached, and the conclusion seems to be that the process 
gives no practical results. 


Until the reseai ches of M. Fremy, no other method of 
producing A1 2 S 3 was known save by acting on the metal 


with sulphur at a very high heat. Fremy was the first 
to open up this new field, and it may be that his discover- 
ies will yet be the basis of successful industrial processes. 
Fremy is often quoted in connection with APS 3 , and in 
order to understand just how much he discovered we here 
give all that his original paper contains concerning this 

" We know that sulphur has no action on silica, boric 
oxide, magnesia, or alumina. I thought that it might be 
possible to replace the oxygen by sulphur if I introduced 
or intervened a second affinity, as that of carbon for 
oxygen. These decompositions produced by two affinities 
are very frequent in chemistry, it is thus that carbon and 
chlorine, by acting simultaneously on silica or alumina, 
produce silicon or aluminium chloride, while either alone 
could not decompose it ; a similar case is the decomposi- 
tion of chromic oxide by carbon bisulphide, producing 
chromium sesquisulphide. Reflecting on these relations, 
I thought that carbon bisulphide ought to act at a high 
heat on silica, magnesia, and alumina, producing easily 
their sulphides. Experiment has confirmed this view. I 
have been able to obtain in this way almost all the sul- 
phides which until then had been produced only by the 
action of sulphur on the metals. 

" To facilitate the reaction and to protect the sulphide 
from the decomposing action of the alkalies contained in 
the porcelain tube which was used, I found it sometimes 
useful to mix the oxides with carbon and to form the mix- 
ture into bullets resembling those employed in the prepa- 
ration of APC1 6 . I ordinarily placed the bullets in little 

* Ann. de Chem. et de Phys. [3] xxxviii. 312. 


carbon boats, and heated the tube to whiteness in the 
current of vaporized carbon bisulphide. The presence of 
divided carbon does not appear useful in the preparation 

.1 2 S 3 formed is not volatile; it remains in the car- 
bon boats and presents the appearance of a melted vitre- 
ous mass. On contact with water it is immediately de- 

Al 2 S 3 -f3H 2 O=Al 2 O 3 +3H 2 S. 

" The alumina is precipitated, no part of it going into 
solution. This precipitated AFO 3 is immediately soluble 
in weak acids. The clear solution, evaporated to dryness, 
gives no trace of alumina. It is on this phenomenon that 
I base a method of analysis as will be seen below. 

"Analysis of the product. A1 2 S 3 being non-volatile, it 
is always mixed with some undecomposed alumina. It is, 
in fact, impossible to entirely transform all the alumina 
into A1 2 S 3 . I have heated less than a gramme of alumina 
to redness five or six hours in carbon bisulphide vapor, 
and the product was always a mixture of Al 2 O 3 and A1 2 S 3 . 
The reason is that the sulphide being non-volatile and fusi- 
ble coats over the alumina and prevents its further decompo- 
sition. The A1 2 O 3 thus mixed with the A1 2 S S , and which 
has been exposed to a red heat for a long time, is very 
hard, scratches glass, and is in grains which are entirely 
insoluble in acids. By reason of this property I have 
been able to analyze the product exactly, for on treating 
the product with water and determining on the one hand 
the sulphuretted hydrogen evolved, and on the other the 
quantity of soluble alumina resulting, I have determined 
the two elements of the compound. One gramme of my 


product contained 0.365 grm. of A1 2 S 3 , or 36.5 per cent., 
the remainder being undecomposed alumina." The com- 
position of this APS 3 was 

Al 0.137 grm. = 37.5 per 

S ... 0.228 " = 62.5 " 

0.365 " 100.0 " 
The formula APS 3 requires 

Al 36.3 per cent. 

8 63.7 " 

The above is the substance of Fremy's remarks on 
APS 3 . The next investigation in this field was made by 
Reichel. His paper is on the sulphides of magnesium and 
aluminium and he proceeded in methods so similar with 
both metals that he sometimes describes a process only for 
magnesium sulphide, MgS, with details, and merely states 
his results in working the same way for APS 3 , which will 
account for the frequent allusion in his paper to MgS. 
The paper is very lengthy, but only what bears directly on 
the subject in hand is extracted. 

" I wished* to obtain more definite knowledge of MgS 
and APS 3 , and I also had a practical end in view ; for, 
depending on the small affinity of sulphur for magnesium 
and aluminium, I hoped, if not to isolate them from the 
sulphide, at least to try the possibilities of this method." 
(As preliminary, Reichel here gives extended remarks on 
the behavior of aluminium and magnesium towards sul- 
phur, and a description of the sulphides.) 

" APS 3 appears yellow, at least that made from the 
metal and sulphur with exclusion of air always has this 

* Jrnl. fr. Prak. Chem. xi . 55. 


color. It is only by heating the metal with sulphur vapor 
with admittance of air that the product is of a darker 

experiments to determine if the preparation 
MgS was not possible in the same way as 
K 2 S, Na 2 S, and BaS are made. For example, by melting 
potassium oxide with sulphur some K 2 S is formed. How- 
ever, on doing this with alumina and magnesia, it became 
evident that magnesium and aluminium have less affinity 
for sulphur than for oxygen, and the experiment failed* 
But, matters were changed when a reducing agent was 
introduced with the sulphur. If a mixture of carbon, 
magnesia, and sulphur are heated, MgS results, which by 
treating the product with water goes into solution un- 
changed. Alumina under similar treatment gave no 
APS 3 . In place of carbon as a reducing agent I next 
used hydrogen. By igniting magnesia in a stream of 
hydrogen and sulphur vapor some little MgS was formed, 
but the mass of the magnesia was unchanged. The next 
step was to substitute sulphuretted hydrogen for hydrogen 
and sulphur separately, but only a little MgS was formed 
in this way. 

" Since the sulphates of calcium and barium are reduced 
to sulphides with very little trouble, it appeared probable 
that magnesium sulphate, MgSO 4 , should be convertible 
into MgS by a reducing agent. The attempts to do this 
were unsuccessful. I heated MgSO 4 in vapor of ammon- 
ium sulphide, but it underwent no change. Since accord- 
ing to Stammer* K 2 SO, CaSO 4 , and BaSO 4 may be re- 
duced to sulphides by carbonic oxide, CO, I tried to 

* Pogg. Ixxxii. 135. 


reduce MgSO 4 by this means. The following reaction 
apparently took place- 

MgSO 4 + 4CO=MgO+COS, + 3CO 2 .^^^ 

" I then took pure magnesia, filled a porcelain tube 
with it, and passed carbon bisulphide vapor througnrt. 
The apparatus was first filled with hydrogen, then as soon 
as the tube was bright red the carbon bisulphide flask was 
warmed, and sulphuretted hydrogen and carbonic oxide 
began to issue from the tube. The heating was continued 
till carbon bisulphide condensed in the outlet tube, then 
the fire was removed and hydrogen passed through the 
tube till it was cold. The MgS resulting was of a gray 
color, not melted, but as a crumbly powder. The reaction 
which took place was probably 

MgO+ 2CS 2 -f-6H=MgS + 3H'S-|-CO+ C. 

" The carbon was left with the MgS; and, to get rid of 
it I heated the tube up as before but passed hydrogen and 
carbonic oxide through, when the hydrogen took up the 
carbon forming probably some hydrocarbon. 

" Than* says that carbon oxysulphide, COS, is formed 
by leading carbonic oxide and sulphur vapor through a 
red-hot tube. The reactions made to take place are 


" The product obtained thus contained 58 per cent. 
MgS and 42 per cent, undecomposed magnesia. In act- 
ing on alumina in the same way, the product obtained is 
a mixture of APS 3 and aluhiina." 

* Jahresb. der Chein., 1867, 155. 


Reichel next tried the different methods which have 
been proposed to reduce these sulphides to metal, and 
thus records his results (see p. 183) : 

" Petitjean* patented a process in England for reducing 
APS 3 by hydrogen acting at a high temperature, or by 
melting it with iron filings. MgS, heated a long time 
in a current of hydrogen, remained unchanged. I mixed 
MgS with iron filings, put it in a porcelain crucible, 
covered with fresh, dry, fine NaCl, and filled the crucible 
to the rim with carbon. To keep out all oxygen, I put 
the crucible inside a larger Hessian crucible, filling in 
between with pulverized charcoal. After heating several 
hours in a wind furnace, I found a half-sintered mass 
under the NaCl. This material, on being boiled with 
water, evolved no trace of hydrogen sulphide but only 
pure hydrogen. This showed that the iron had taken the 
sulphur from the MgS. Still, I did not succeed in ex- 
tracting the free magnesium from it by amalgamation. 
In the same manner, A1 2 S 3 appeared to be decomposed by 
iron and heat, but it was also impossible in this case to 
separate the metallic aluminium out of the mass. Copper 
effects the reduction as well as iron, forming CuS. 

" Since magnesium is not sulphurized on ignition in a 
current of hydrogen sulphide, it appeared probable that 
MgS might be reduced by ignition in a stream of hydrogen. 
I first tried a current of illuminating gas, well dried and 
freed from hydrogen sulphide by a potash tube. In spite 
of long ignition, the MgS was unaltered. Then I tried 
hydrogen, but that also was unsuccessful, the MgS would 
not give up its sulphur to hydrogen at a bright red heat. 
Since hydrogen alone does not act on MgS, it is hardly 

* Dingier, 148, 371. 


to be expected that a hydrocarbon can remove any sulphur 
from it. 

" To find how carbonic oxide acted towards MgS, I ig- 
nited the latter in a stream of this gas. The magnesium 
sulphide used contained 56.5 per cent, sulphur and 33.0 
per cent, magnesium, or 12.47 per cent, more sulphur 
than the formula MgS allows. Under these circumstances 
COS was evolved, recognized by forming barium sulphide 
and sulphate, when led into baryta water. As soon as 
these gases ceased coming off, I cooled the tube in a current 
of carbonic oxide. The material had retained its former 
color and still readily evolved hydrogen sulphide in moist 
air or water. But it had lost 12.23 per cent, of its weight. 
The gas, it appears, had united only with the sulphur in 
excess of that required to form MgS, and the polysulphide 
was thus changed to the monosulphide." 

Reichel makes the following summary: 

" The above researches show that magnesium and alu- 
minium can unite with sulphur directly at a high temper- 
ature. Also, that MgS and Mg 2 OS will be formed when 
magnesia is similarly treated. Alumina is unattacked by 
sulphur. Alumina and magnesia are changed by ignition 
in carbon bisulphide to sulphides. When carbon bisulphide 
and oxide act on magnesia, Mg 2 OS remains ; alumina is un- 
changed. Magnesia is changed by ignition in hydrogen 
sulphide to MgS, but the operation is tedious and imper- 
fect. By melting the oxides with sulphur no sulphides can 
be obtained ; with alumina the contemporaneous action of 
a reducing agent is necessary, while magnesia melted with 
carbon and sulphur or heated in hydrogen and sulphur 
vapor becomes MgS. 

" APS 3 possesses a yellow color, is with difficulty fusi- 


ble, but fuses to a hard crystalline mass. Usually it is 
obtained as a sintered yellow powder. In damp air or 
water the following reaction takes place: 

APS 3 +6H 2 O==A1 2 (OH) 6 + 3H 2 S. 

" It burns in the air to alumina and sulphur dioxide. 
MgS forms a polysulphide, as we have seen, but APS 3 does 

" Also, APS 3 and MgS appear to be reduced at a high 
heat by metals which have a greater affinity for sulphur, 
yet it remains to be seen whether this property is techni- 
cally valuable." 

Leaving these two experimenters, Fremy and Reichel, 
we have very few allusions to the subject. Those who 
have proposed to produce aluminium from APS 3 state 
merely that they use Fremy 's process for preparing the 
APS 3 . 

We have found an article* in which it is proposed to pass 
vapor of carbon bisulphide and hydrochloric acid together 
over ignited alumina, APS 3 being formed as an intermedi- 
ate product , and APC1 6 ultimately formed by the action of 
the acid. The writer states that by passing the first alone 
over the ignited alumina the gas evolved is mostly COS, 
though a portion of it is decomposed to sulphur and car- 
bonic oxide. He further states that APS 3 is only slightly 
acted on by sodium chloride, is unaffected by calcium or 
magnesium chlorides, slightly acted on by potassium chlor- 
ide, but readily chloridized by hydrochloric acid. 

F. Lauterborn (see p. 206) claims in a patented process 
that by calcining aluminium fluoride with calcium sulphide 

* Chem. News, Dec. 19, 1873. 


APS 3 results. I cannot find any corroboration of this 

Mr. Niewerth's process for reducing aluminium, in which 
he either uses APS 3 or else makes it as an intermediate 
product, will be found in full on p. 185, it being too long 
to repeat here. I cannot find any outside testimony as to 
the possibility of his schemes. 

Reichel has probably proven the possibility of reducing 
APS 3 by a metal having more affinity for sulphur. From 
a chemical standpoint its reduction by copper, iron, etc., 
should be under the proper conditions a very easy opera- 
tion. These conclusions follow from the relative affinity 
of sulphur for the metals, which is set forth in the follow- 
ing investigation : 

" A. Orlowsky* has studied the affinity of sulphur 
for the metals. From his researches it was found that 
it usually possesses the greatest affinity for the alkaline 
metals, with which it forms polysulphides. Among the 
other metals, copper possesses the greatest affinity for sul- 
phur, then follow in order mercury, silver, iron, lead, and 
after these platinum, chromium, aluminium, and magne- 
sium, whose affinities for sulphur are quite insignificant." 


Taking the data given in the foregoing papers, I made 
a series of experiments on first making APS 3 and then 
on reducing it. 

Experiment L 

Took pure, white alumina, made by calcining pure sul- 

* Jahresb. der Chemie, 1881, p. 24. 


phate of alumina, put it in porcelain boats in a hard glass 
tube, and passed vapor of carbon bisulphide, CS 2 , over it 
at bright redness for forty-five minutes. The product was 
cooled out of contact with the air. The result was a gray- 
ish-black powder, not sintered together in the least. On 
analyzing the product by Fremy's method, it showed 12.65 
per cent, of A1 2 S 3 . 

Experiment II. 

Took equal parts of alumina, sulphur, and charcoal, 
ground intimately together in a mortar, and served as in 
Experiment I, prolonging the action of CS 2 to an hour and 
a half. The product was a grayish-black powder, similar 
in appearance to the former product. It contained 38.51 
per cent. APS 3 . 

Experiment III. 

Repeated Experiment I, but used a porcelain tube, thus 
allowing a higher heat than the glass tube would stand. 
The treatment lasted an hour and a half. The product 
was of similar appearance to the previous ones, and con- 
tained 39.54 per cent. Ai 2 S 3 . 

Experiment IV. 

I placed some ordinary aluminium sulphate, A1 2 (SO 4 ) 3 .- 
18H 2 O, in the porcelain tube, and heated it gradually up 
to bright redness with the tube open at both ends, cal- 
cining it thus for two hours. The result was that the tube 
was filled with very porous alumina. CS 2 was then passed 
over it for two hours, the whole being kept at redness. 
The product was dirty-white, but lemon-yellow in places, 
and at the yellow parts sintered together, Analyzing an 


average specimen, it showed 31.16 per cent, APS 3 . It is 
probable that if a yellow piece had been singled out it 
would have shown much 'more APS 3 than this average 

Experiment V. 

I placed some pure alumina in small hollows cut in 
pieces of charcoal, and placed these in the tube instead of 
the porcelain boats. The tube was then placed in an 
assay furnace and heated almost to whiteness for an hour 
and half, CS 2 being passed through. The product was 
small, black, fused buttons melted down into the bottoms 
of the cavities in the charcoal. These lumps were black 
outside, brittle, compact fracture, and the broken surfaces 
mottled, dirty-white, and yellow. They had a strong smell 
of hydrogen sulphide, and when dropped into water this 
gas was evolved so actively as to make quite a buzz, resem- 
bling the action of a piece of zinc dropped into acid. In 
one or two minutes the button was resolved into a black 
pow r der. This product contained 40.43 per cent. APS 3 . 

Experiment VI. 

Repeated Experiment V, but used porcelain boats. The 
product was still dark, and contained 38.80 per cent. APS 3 . 

Experiment VII. 

Wishing to make a quantity of the substance, I filled 
the tube with alumina, put it in a hot fire, and passed CS 2 
over it three hours. The product was grayish-black, with 
here and there touches of yellow, with lumps of consider- 
able size sintered together. An average sample of it con- 
tained 32.32 per cent. APS 3 . 


Tabulating these results we have 

Experiment I. II. III. IV. V. VI. VII. 
Al*S 3 (p.ct.) 12.65 38.51 39.54 31.16 40.43 33.80 32.32 

First I would notice that, as remarked by Fremy, the 
APS 3 formed incloses the particles of alumina and prevents 
further action. It seems highly probable that a stirring 
apparatus to keep the alumina agitated would greatly im- 
prove the product. Experiment I gave poor results because 
the heat was not sufficient ; Experiment II was done at a 
higher heat, with addition of carbon, and Experiment III 
at a still higher heat, without carbon. It appears from 
this that the presence of carbon had very little influence 
on the amount of A1 2 S 3 produced. Experiment V, giving 
the best results, was worked, I think, at a higher heat than 
any of the others ; but Experiment VI was conducted 
under as nearly as possible the same conditions ; however, 
we may consider the products as being nearly enough 
alike, the carbon does not appear to have made a marked 
difference in the product. 

To establish such a process on a practical scale, a 
wrought-iron or fire-clay retort would be necessary, with 
arrangements to heat it almost to whiteness. Boats of 
charcoal, holding ample charges of alumina, are made to 
fit in the retort. Some sort of stirring apparatus to agi- 
tate the alumina from time to time should be provided. 
The CS 2 could be brought in superheated by waste heat 
from the furnace and passed out into a condenser. Or, to 
economize still further, the retort might be lengthened, its 
forepart made a producer of CS 2 , by passing sulphur vapor 
over carbon, and the rear part be filled with the alumina to 
utilize this CS 2 . Many other devices will occur to the 


practical chemist in running such a process, the above 
being mere suggestions. 


Experiment VIII. 

I took about half a gramme of product of VII, and 
wrapping it tightly in lead-foil placed it on a cupel and 
heated in a muffle. Air was kept from the metal by a 
close-fitting porcelain cover. On removing the lid after a 
few minutes, there appeared a button of lead with some 
powder on its surface. I then cupelled the lead at as 
low a temperature as possible. The metal cupelled away 
entirely, leaving no aluminium. On repeating with every 
precaution the result was the same. 

Experiment IX. 

About one gramme of product VII was wrapped in 
copper foil, put in a porcelain crucible, and covered with 
NaCl and a little charcoal. A close cover was put on, 
the whole placed in the middle of a Hessian crucible, the 
latter filled up with fine charcoal, and a cover luted on. 
On heating this an hour at bright redness, hardly white- 
ness, there resulted a large button of copper. However, its 
specific gravity was that of pure copper, and a qualitative 
test showed no trace of aluminium. It occurs to me now 
that probably the NaCl reacted on the APS 3 , forming alu- 
minium chloride and sodium sulphide, preventing the 
action of the copper. 

Experiment X. 

Repeated Experiment IX with tinfoil, and heating only 
twenty minutes. The tin resulting showed some alumin- 


him on a qualitative test, and on analyzing it I found 0.52 
per cent. Considering the small amount of sulphide and 
the rather large amount of tin used, it is probable that 
nearly all the aluminium present as APS 3 was reduced. 

Experiment XL 

Repeated the same, but using powdered antimony to 
mix with the APS 3 . The resulting button was pure anti- 
mony with no aluminium in it. 

Experiment XII. 

Repeated the experiment, employing fine iron filings and 
using a high heat for one and a half hours. The product 
was a loose mass in which were small buttons of metal. 
These buttons were bright, yellower than iron, and con- 
tained 9.66 per cent, aluminium. 

Lack of time and opportunity prevented my extending 
these experiments on reduction. I had intended trying 
copper filings, zinc filings, mercury excluding air by 
using a vacuum or an atmosphere of hydrogen or its re- 
duction by hydrogen gas. 

On reviewing the experiments reported above, those with 
tin and iron succeeded best. Knowing the great affinity 
of copper for sulphur, I cannot but think that an experi- 
ment with very fine copper filings intimately mixed with 
the APS 3 would give satisfactory results. 

In closing I would remark that a process such as sug- 
gested on p. 321 could be easily arranged on a large scale, 
the undecomposed CS 2 being caught and so no more of it 
used than is necessary to supply sulphur for the A1 2 S 3 . 
The product could be mixed with fine metallic filings, 'put 
into a crucible, surrounded by charcoal, and the alloy 


made. The metal changed to sulphide could be recovered 
by reducing the slags. These processes have been covered 
by patents, but have never been made successful. It ap- 
pears that if rightly managed they will give good results 
and produce aluminium alloys cheaply. 



" In the ordinary sodium process,* lime is added to the 
reducing mixture to make the mass refractory, otherwise 
the alkali would fuse when the charge is highly heated, 
and separate from the light, infusible carbon. The carbon 
must be in the proportion to the sodium carbonate as four 
is to nine, as is found needful in practice, so as to assure 
each particle of soda in the refractory charge having an 
excess of carbon directly adjacent or in actual contact. 
Notwithstanding the well-known fact that sodium is 
reduced from its oxides at a degree of heat but slightly 
exceeding the reducing point of zinc oxide, the heat 
necessary to accomplish reduction by this process and to 
obtain even one-third of the metal in the charge, closely 
approaches the melting point of wrought iron. 

** In my process, the reducing substance, owing to its 
composition and gravity, remains below the surface of the 
molten salt, and is, therefore, in direct contact with the 

* Journal of the Franklin Institute, Nov. 1886. 


fused alkali. The metallic coke of iron and carbon con- 
tains about 30 per cent, carbon and 70 per cent, iron, 
equivalent to the formula FeC 2 . I prefer to use caustic 
soda, on account of its fusibility, and mix with it such 
quantity of so-called ' carbide' that the carbon contained 
in the mixture shall not be in excess of the amount theo- 
retically required by the following reaction : 

SXaOH + FeC 2 = 3Na + Fe + CO+ CO 2 + 3H ; 

or, to every 100 pounds of pure caustic soda, seventy- 
five pounds of * carbide,' containing about twenty-two 
pounds of carbon. 

" The necessary cover for the crucible is fixed station- 
ary in each chamber, and from this cover a tube projects 
into the condenser outside the furnace. The edges of the 
cover are convex, those of the crucible concave, so that 
when the crucible is raised into position and held there 
the tight joint thus made prevents all leaking of gas or 
vapor. Gas is used as fuel, arid the reduction begins 
towards 1000 C. As the charge is fused, the alkali and 
reducing material are in direct contact, and this fact, 
together with the aid rendered the carbon by the fine 
iron, in withdrawing oxygen from the soda, explains \vliy 
the reduction is accomplished at a moderate temperature. 
Furthermore, by reducing from a fused mass, in which 
the reducing agent remains in suspension, the operation 
can be carried on in crucibles of large diameter, the 
reduction taking place at the edges of the mass, where 
the heat is greatest, the charge flowing thereto from the 
the centre to take the place of that reduced. 

" I am enabled to obtain fully ninety per cent, of the 
metal in the charge, instead of thirty per cent, as formerly. 


The crucibles, after treatment, contain a little carbonate 
of soda, and all the iron of the ' carbide' still in a fine 
state of division, together with a small percentage of. car- 
bon. These residues are treated with warm water, the 
solution evaporated to recover the carbonate of soda, while 
the fine iron is dried, and used" over again for ' carbide."' 


Mr. Cha's. F. Mabery has patented and assigned to 
Cowles Bros, a new process for making anhydrous alu- 
minium chloride. The patent was granted Oct. 26, 1886. 
The first claim is for producing it by passing chlorine gas 
over an alloy of aluminium and some other metal kept in 
a closed vessel at a temperature sufficient to volatilize the 
APC1 6 formed, which is caught in a condenser. The 
second claim is for passing hydrochloric acid gas through 
the electric furnace in which alumina is being decomposed 
by carbon, a condenser being attached as before. 


Mr. W. H. Wahl, Secretary of the Franklin Institute, 
Phila., makes the following remark on this subject: * 

" The simplicity of this process, the certainty with 
which it can be operated, the uniformity of the product, 
and its good qualities in respect to strength and ductility, 
indicate an extended field of usefulness for it. The mitis 
castings threaten to seriously incommode the manufac- 
turers of malleable castings, for which they not only offer 

* Journal of the Institute, Nov. 1886. 


a perfect substitute, but one which, in respect to strength 
and ductility, is distinctly superior, while for many pur- 
poses mitis castings can be employed for which malleable 
castings could not be made. The mitis process has also 
been applied to the production of steel castings, and with 
promising results. In one of the methods experimentally 
tested, the sheet castings were from wrought iron scrap 
as raw material, with the addition of the proper propor- 
tion of cast iron to bring the percentage of carbon to the 
point required for each special purpose." 


From advance proof-sheets of vol. iii. 'Mineral Re- 
sources of the United States,' we learn* that the produc- 
tion of metallic aluminium in the United States increased 
from 1800 troy ounces in 1884 to 3400 ounces in 1885, 
valued at $2550. Aluminium bronze, ten per cent., was 
made to the amount of about 4500 pounds, valued at 

In October, 1886, a Philadelphia instrument maker 
accepted the offer, from the maker, of a large amount of 
European aluminium at the price of 50 cents per ounce, 
the lowest at which aluminium has yet been sold. 

* Sci. Am., Nov. 13, 1886. 


Academy, Paris, patronage of, i Alloys of aluminium and mer- 

towardfi Deville, 32 
Acetic acid, action of, on alu- 
minium, 78 

Acid, acetic, action of, on alu- 
minium, 78 
hydrochloric, action of, on 

aluminium, 75 
muriatic, action of, on alu- 
minium. ?."> 

nitric, action of, on alu- 
minium, ~~) 

sulphuric, action of, on alu- 
minium, 74: 

tartaric, action of, on alu- 
minium, 78 

Acids, organic, action of, on alu- 
minium, 78 
Air. action of, on aluminium, 


Albite, formula of, 43 
Alkalies, caustic, action of, on 

aluminium, 77 
Alkaline carbonates, action of, 

on aluminium, 88 
Alloys, aluminium, made by 

Cowh's Bros., 205 
of aluminium, 258-303 
and antimony. 21'2 
and bismuth' 292 
and boron, 1199 
and cadmium, 299 
and carbon. Moo 
and copjXT, 204: 
and gallium, 300 
and gold. 
and iron, 280 
, and lead, -J'. > L 
and mangan 

cury, 201 
and molybdenum, 302 
and nickel, 293 
and nitrogen, 303 
and platinum, 299 
and silicon, 259 
and silver, 295 
and sodium, 303 
and tin, 289 
and titanum, 301 
and tungsten, 302 
and zinc, 287 
with steel, 281 
of brass and aluminium. 276 
of German silver and alu- 
minium, 277 

Alumina, composition of, pre- 
cipitated, 105 

crucibles, use of, for obtain- 
ing aluminium, 228 
in purifying alumin- 
ium, 243 
extracted from alum stone 

or shale, 153 
manufacture of, 144-153 
manufactured from cryolite, 


dry way, 14/> 

wet way, 152 

precipitation of, by carbonic 

acid gas, 149 
reduction of, by carbon in 

presence of copper, 309 
sulphate of, Tilghman's pro- 
cess for decomposing, 144 
Aluminate of soda crucibles, use 
of, in purifying alu- 
minium. 24:?' 



Aluminate of soda precipitation 

by Lovvig, 151 
precipitation of, at Sal- 

indres, 159, 103 
Aluminite, formula of, 44 
Aluminium, alloys of, 258-303 
amalgam, properties of, 263 
bronze, solders for, 279 
chemical properties of, 70- 

Crown Metal Co.'s, 173 

makers of alumin- 
ium bronze, 274 
crucibles, use of, for obtain- 
ing aluminium, 228 
history of, 25-42 
manufacture at Salindres 

(Gard), 158-171 
metallurgy of, 90-257 
occurrence in nature, 43-50 
physical properties of, 51-70 
plate as a substitute for tin 

plate, 247 
protoxide, 26 
reduction of, by other agents 

than sodium, 180 
silver, 297 
sodium, double chloride, 

making of, 154-157 
uses of, 243-247 
working in, 235-257 
Alum-shale, use of, for making 

alumina, 153 
Alum-stone, use of, for making 

alumina, 153 

Alums, native, impurities in, 45 
Alunite, formula of, 44 
Amalgam, potassium, used in 

isolating aluminium, 25 
Amalgamation of aluminium, 

261, 308 

Wohler's efforts, 25 
American aluminium, 306 
Co., Detroit, 221 , 
price of, 1883-84, 39 
cryolite, 48 

Amfreville-la-mi-Voie, alumin- 
ium works at, 29, 33 
process used at, 124 
Ammonia, aqua, action of, on 

aluminium, 78 
Analyses of beauxite, 46 

Analyses of commercial alumi- 
nium, 51, 52 
of Mr. Frishmuth's metal, 

Analysis of aluminium sulphide, 


of Bombay Wootz for alu- 
minium, 283 
Animal matters, action of, on 

aluminium, 87 
Animals, aluminium never found 

in, 44 

Annealing of aluminium, 58 
Anorthite, formula of, 43 
Antimony, alloys of aluminium 

with, 292 

reduction of aluminium sul- 
phide by, 323 

Argentan, a serviceable alloy, 294 
Artistic purposes, use of alumin- 
ium for, 245 

Balance beams, special value of 

aluminium for, 35 
Barattes for precipitating alu- 
mina, 163 
Barium, alloys with aluminium, 

oxide, action on aluminium, 

Barlow, W. H., on the tensile 

strength of aluminium, 62 
Basset, M. N., reduction of alu- 
minium by zinc, by, 215 
Battersea, London, first alumin- 
ium works in England, 33 
Battery, use of aluminium in 

the, 75 

to deposit aluminium, 80 
Baudrin, P., on a new aluminium 

alloy, 278 

Beating of aluminium, 57 
Beaux, analysis of beauxite from, 


Beauxite, 45-47 
analyses of, 46 
and cryolite, chief source of 

aluminium, 45 
stimulated production 

of, 27 

deposits in Ireland, France, 
etc., 46 



Beauxite. formula of, 44 

treatment of, at Saliudres, 

where principally found in 

France, 100 
Beketoff, on the action of oxide 

of barium on aluminium, 87 
Bell Bros., directions for solder- 
ing aluminium, 252 
makers of aluminium at 
Newcastle-on-Tyne, 33 
stoppage of their alu- 
minium works, 35 
Bells, aluminium, 63 
Benjamin, Mr., additional details 
of Castner's sodium process, 

Benzine, use of, in melting alu- 
minium, 230 

Benzon, iron process of, 211 
Berlin, aluminium works in, 35 
Bertrand, M. A., deposition of 

aluminium by electricity, 232 
Berzelius, investigation on the 

composition of cryolite, 104 
Bessemer converter, reduction of 
aluminium in the, 207 
reduction of sodium and 

potassium in, 208 
Birmingham, England, Webster's 

aluminium works at, 36 
Bismuth, alloys of aluminium 


Blast furnace, reduction of alu- 
minium in a, 185-204 
Books on aluminium, Tissier 

Bros., 28 
Deville's. 20 
Mierzinski's, 9 
Borates, action of, on aluminium, 

Boron, alloys of aluminium with, 


Boudaret, M., report on the mal- 
leability of aluminium bronze, 


Bourbouze, M., on an aluminium 

tin alloy, 290 
Brass, aluminium, strength of, 


compared with aluminium 
bronze, 27 1 

Braun, John, deposition of alu- 
minium by electricity, 2^53 
Bremen, aluminium works at. 

229 ' 
Bromide of aluminium used for 

making pure aluminium, 243 
Bromine, action on aluminium, 88 
Bronze, aluminium, 264 
a true alloy, 265 
compared with brass, 271 
compressive strength of, 


Cowles Bros., 274 

first exhibited at Paris, 

1867, 34 
making of, 267 
malleability of, 267 
manufactured by M. 

Evrard, 211 
melting point of, 271 
phosphorized. 279 
price in 1878, by the So- 

ciete Anonyme, 36 
production in the United 

States in 1885, 327 
specific gravity of, 271 
tenacity of, 266, 267, 270, 


silicon-aluminium, 205,280 
silicon, manufactured by M. 

Evrard, 211 
B runner, reduction of sodium by, 


Buchner, G., purification of alu- 
minium from silicon, by, 243 
Buff and Wbhler on the solution 

siliceous aluminium, 260 
Bunsen and Deville's electrolytic 
method of separating alumin- 
ium, 41 

Bunsen, electrical process of, for 
depositing aluminium, 222, 225 
Burnishing of aluminium, 55 

Cadmium, alloys of aluminium 

with, 299 
Caillet, on the amalgamation of 

aluminium, 261 
Calcination furnace for sodium 

mixture, 133 
Thomson's, for cryolite, 



Calcination retorts for alumi- 
nium-sodium chloride at Sa- 
- lindres, 166 

Calcutta, aluminium at the ex- 
hibition of, in 1883, 246 
Calvert and Johnson, making of 
iron aluminium alloys, 
reduction of aluminium 

by iron, 209 
Camden, N. J., aluminium made 

at, 31 

Carbon, action on aluminium, 88 
alloys of aluminium with, 


and aluminium, alloy of, 203 
and carbon dioxide, reduc- 
tion of aluminium by, 187 
as lining for earthen cruci- 
bles, 36 

changed to graphite, 193 
dioxide and carbon, reduc- 
tion of aluminium by, 187 
disulphide, use of, for making 
aluminium chlo- 
ride, 317 

for making alumin- 
ium sulphide, 310 
reduction of aluminium by, 

Carbonates of alkalies, action on 

aluminium, 88 
Carbonic acid gas, lime-kiln for 

producing, 150 
used for precipitat- 
ing aluminium, 
149, 163 
Carburetted hydrogen, reduction 

of aluminium by, 182 
Casting of aluminium, 237 

its importance, 36 
the largest ever 

made, 39 
Castings, Mitis, alloy used for 

making, 212 

Castner, claims made in his pat- 
ent, 141 
process for reducing sodium 

by, 324 

reduction of sodium by, 131 
Chalk, object of using, in the 
reduction of sodium, 133 

Chanu, aluminium plant at 

Rouen, 29 
Chapelle, M., on the reduction 

of aluminium by carbon, 188 
Charridre, on soldering alumin- 
ium, 248 
use of an aluminium tube in 

tracheotomy, 87 

Chemical classification of alu- 
minium, 88 
properties of aluminium, 


reactions in the sodium pro- 
cess, 158 

Chemically pure aluminium, di- 
rections for making, 243 
Chlorhydrate of aluminium, 85 
Chloride of aluminium, a new 
process for producing, 

Dullo's process for mak- 
ing, 155 
improved method for 

producing, 157 
Chlorides, metallic, action on 

aluminium, 85 
Chlorine, action on aluminium, 

Christofle, M., castings of alu- 

mipium bronze, 265 
gilding of aluminium, 80 
on soldering aluminium, 248 
on the use of aluminium- 
silver alloy, 296 

Classification, chemical, of alu- 
minium, 88 
Clay, cryolite, as lining for 

earthen crucibles, 36 
Clays, alumina the base of, 43 
Cleaning of tarnished alumin- 
ium, 54 

Cleveland, manufacture of alu- 
minium in, 41, 190 
Coating of metals with alumin- 
ium, 231 

iron with aluminium, 247 
Coins, use of aluminium for. 


Color of aluminium, 53 
Combinations of aluminium, 43 
Combustion of aluminium leaf, 



Comenge, M., double reaction 

method of, 
Commercial aluminium, analyses 

of, 51 
made chiefly by Deville's 

process, 41 

Compressive strength of alu- 
minium bronze, 2~2 
Condenser for sodium, 131 
Conductivity of aluminium for 

heat, 67 

electric, of aluminium, 66 
Converter, the Bessemer, reduc- 
tion of aluminium in, 
reduction of sodium and 

potassium in, 208 
Cooking, aluminium utensils for, 

utensils, valuable property 

of aluminium for, 68 
Copper, alloys of aluminium 

with, 264-280 
deposition of, by aluminium, 

freeing of aluminium from, 

oxide, action on aluminium, 

reduction of aluminium by, 

of aluminium-sulphide 

by, 322 

the quality suitable for alu- 
minium bronze, 267 
Coppering of aluminium, 80 
Corbelli, of Florence, cyanogen 

process of, 180 
process of, for deposit- 
ins: aluminium elec- 
trolytically, 231 
Cornwall, supposed discovery of 

native aluminium at, 43 
Corundum, 49, 50 

discovery in Georgia, 49 
from Georgia, used by 

Cowles Bros., 205 
price at the mim->. 40 
use of, for making alumin- 
ium, 37 

Cost of aluminium at Salindres 
in is;:.', 172 

Cowles's aluminium process, his- 
tory of, 41 
Cowles Bros.' agent in England, 

aluminium bronze made 

by, 274 
aluminous materials used 

by, 205 

owners of a patent for 
producing aluminium 
patent claims, 190 
process for the reduction 
of aluminium by car- 
bon, 189-205 

Cross, W., description of Ame- 
rican cryolite, 48 
Crucible clay, action on alumin- 
ium, 84 
Crucibles, action of aluminium 

on siliceous, 259 
alumina, use of, for obtain- 
ing aluminium, 228 
in purifying alumin- 
ium, 243 

aluminate of soda, use of, 
in purifying aluminium, 

aluminium, use of, for ob- 
taining aluminium, 228 
earthen, action of aluminium 

on, 35 
iron, used by Rose, 106 

use of, in purifying alu- 
minium, 241 

lime, for melting alumin- 
ium, 36 

lining for, 35, 123 
porcelain, use of, for obtain- 
ing aluminium. 228 
used in electrolyzing alu- 
minium, 224 

Cryolite, Allen Dick's experi- 
ments on reduction of, 115 
and Beauxite, chief source 

of aluminium, 45 
stimulated production 

of, 27 
Berzelius's investigation of 

its composition, 104 
clay as lining for earthen 
crucibles, 36 



Cryolite, composition of, 119 
decomposition of, 306 
by electricity, 230 
Deville's process for reduc- 
ing, 119-126 
Dr. Percy's experiments on 

reducing, 115 
formula of, 44 
general use as a flux, 48 
H. Rose's paper on reduction 

of, 103-1 15 

importation of, by the Penn- 
sylvania Salt Co., 48 
imports into the United 

States, 49 

in the United States, 48 
manufacture of alumina 

from, 146-153 
occurrence of, 48, 49 
reduction of, 103-129 
at Nanterre, 126 
by ferro-silicum, 207 
Watts's summary of its use, 

Crystalline form of aluminium, 


Crystallization of aluminium , 115 
Crystallized silicon, 260 
Culinary articles, use of alumin- 
ium for, 68, 245 
Cupellation of aluminium, 71 

from lead, 291 
Curaudau, reduction of sodium 

by, 131 

Cyanite, formula of, 44 
Cyanogen, reduction of alumin- 
ium by, 180 

Davy, reduction of sodium by, 

unsuccessful efforts to isolate 

aluminium, 25 
Debray, H., aluminium plant at 

Glaciere, 28 

Debray, M., statement of, in re- 
gard to iron in aluminium, 282 
Decomposition furnace for so- 
dium mixture, 134 
of aluminium sulphide by 

water, 311, 317 

Degousse, first successful beater 
of aluminum leaf, 58 

De la Rive, on the action of sul- 
phuric acid on aluminium, 74 
Denis, M., of Nancy, remark on 
the soldering of aluminium, 

Density of aluminium, 64 
Deposition of aluminium by elec- 
tricity, 255 
by the battery, 80 
electrolytically, 222-234 
Deville, aluminium plant at Gla- 

cidre, 28 

analysis of beauxite by, 47 
book on aluminium, 1859,29 
charges against Tissier Bros., 


conclusion of his book, 30 
description of the reduction 

of sodium, 132 
experiments on gilding and 

silvering aluminium, 256 
H. St. Claire, first to isolate 

pure aluminium, 26 
on soldering of aluminium, 

on the aluminium obtained 

by Wbhler, 95 . 
on the casting of aluminium, 

on the electrolytic reduction 

of aluminium, 223, 225 
on the melting of alumin- 
ium, 235 

on veneering with alumin- 
ium, 253 
purification of aluminium, 


researches of, at the Normal 
School, Paris, and at 
Javel, 28 

on cryolite by, 118 
review of Percy's and Rose's 
investigations of cryolite, 

treatment of silicates and 
borates with aluminium, 84 
Deville's cryolite process, Wo li- 
ter's improvement on, 126 
improvements in 1854 for ob- 
taining pure aluminium, 96 
processes, later improve- 
ments on, 173 



Deville's sodium vapor process, 

Diaspore, formula of, 44 

where found, 50 
Dick, Allan, paper on reducing 

cryolite, 116 
Disthene, reduction of, by an 

electric current, 229 
Donny and Mareska, condenser 

for making sodium, 131 
Double reaction, reduction of 

aluminium by, 1*4 
Drawing of aluminium into wire, 

Drecbsler, analysis of beauxite 

by, 47 
Dublin, analysis of beauxite 

from, 47 

Ductility of aluminium, 60 
Dullo, M., process for making 

aluminium chloride, loo 
remark on the reduction of 

aluminium by zinc, 214 
Dumas, on gases in aluminium, 

Duvivier. M., on reduction of 

aluminium by electricity, 229 
Dynamo used in Cowles Bros.' 

process, 204 

Elastic rangre of aluminium, 62 
Elasticity of aluminium, (U 
Electric conductivity of alumin- 
ium. 5H 

furnace, Cowles Bros., 199 
suggested by Miefzinski, 


use of, for producing 
aluminium chloride, 
Electrical furnace, gases from 

the, 197 

separation of aluminium, 255 
Electricity applied to melting 
* steel, 194 
to the extraction of 

metals, 1J4 
reduction of aluminium by, 


of sodium by, 131 
un.-uccessful efforts of Davy 
to i>olatc aluminium by. '!) 

Electrolytic methods of separat- 
ing aluminium, 41 
Enamelling mixture to protect 

sodium retorts, 135 
England, Cowles Bros.' agent in. 


failure of aluminium manu- 
facture in, 35 

first aluminium w r orks in, 33 
Webster perhaps the only 
maker of aluminium in, 42 
Engraving of aluminium, 61 
Evrard, M., making of alumin- 
ium bronze by, 211 

Falk & Co., makers of alumin- 
ium leaf, 60 

Faraday's experiments on the 
sonorousness of aluminium, 64 
Farmer, Moses G.. patented ap- 
paratus of, for electrolytically 
obtaining aluminium, 233 
Favre, M., on solution of alu- 
minium in hydrochloric acid, 
Feisstritz, analysis of beauxite 

from, 47 

Ferro-silicum, reduction of alu- 
minium by, 206 
Fixity of aluminium, 66 
Fleury, A. L., carbu retted hy- 
drogen process of, 182 
Fluoride of aluminium, Ger- 
hard's process of re- 
ducing, 181 
Lauterborn's process of 

reducing, 206 
reduction by ferro-sili- 

cum, 206 
Fluorides as fluxes, 260 

use of, as flux, 102-120 
Fluorine, action on aluminium, 

Fluorspar, action on aluminium. 

Flux, fluorspar as, 84 

use of fluorides as a, 102-120 
Fluxes for aluminium, 259 
Formulae of aluminous minerals, 


France, deposits of beauxite in, 



France, production of aluminium 

in, 1882, 39 
successful manufacture of 

aluminium in, 35 
Fremy, original paper on alu- 
minium sulphide, 310 
Frishmuth, aluminium works in 

Philadelphia, 37 
analyses of the metal of, 306 
improvement of, in making 
aluminium-sodium double 
chloride, 154 

plating with aluminium- 
nickel, 234 
production of aluminium, 

1883, 1884, 40 
solders for aluminium by, 

Frishmuth's first assertions not 

verified, 42 
patent claims, 178 
owners of, 37 
process mentioned in Watts's 

Dictionary, 42 
works, annual production 

of, 39 

Fritz, Mr., of Bethlehem, Pa., 
interest of, in the mitis process, 

Fusibility of aluminium, 65 
Furnace, Thomson's, 146 

Gallium, alloys of aluminium 

with, 300 

Garnet, formula of, 44 
Gases in aluminium, 52 

from the electrical furnace, 


Gaudin, electric process of, 230 
Gay Lussac, reduction of sodium 

by, 131 

Gerhard & Smith, patent process 
of, for depositing aluminium, 

Gerhard, W. F., furnace for re- 
ducing aluminium, 127 
German silver, aluminium, 277 
Germany, aluminium works in, 


failure of aluminium manu- 
facture in, 35 

reduction of aluminium in, 

Gila River, N. M., native sul- 
phate of alumina on the, 305 
Gilding of aluminium, 80, 256 
Glacire, process for making alu- 
minium, as used at, 98 
purification of aluminium 

from slag at, 239 
Rousseau Bros., aluminium 

works at, 28 
Glass, action of, on aluminium, 


Gmelin, an observation on alu- 
minium amalgam, 263 
Gold, allo\'s of aluminium with, 


Gordon, A., on the tensile 
strength of aluminium bronze, 
Gore, deposition of aluminium 

on copper, 234 
Granite, composition of, 43 
Graphite, carbon changed to, 


cylinders, use of, to protect 
retorts in sodium reduc- 
tion, 135 

Gratzel, Richard, electrolytic pro- 
- cess of, 228 
Gravity, specific, of commercial 

aluminium, 307 
Greenland, cryolite in, 48 
Grousilliers's improvement of re- 
ducing under pressure, 179 
Guettier, remarks on aluminium 

bronze, 273 

Guiana, deposits of beauxite in, 

Hadamar, analysis of beauxite 
from, 47 

Hamburg, aluminium works at, 

Hardness of aluminium, 61 

Harmlessness of aluminium salts 
to the body, 79 

Havrez, P. J., washing appara- 
tus of, 149 

Heat, conduction of, by alumin- 
ium, 07 
specific, of aluminium, 68 

Helmet, an aluminium, 245 

Herreshoff', importer of beauxite 
into the United States, 47 



Hesse, analysis of beauxite frora, 


deposits of beauxite in, 46 
Hillebrand, description of Amer- 
ican cryolite, 48 
Hirzel, on alloys of aluminium 

and silver, 296 

History of aluminium, 25-42 
Hodges, F., analysis of beauxite 

by, 47 
Hulot, coppering of aluminium, 


method of soldering alu- 
minium, 248 
on the use of aluminium in 

the battery, 75 

Hunt, Dr. T. Sterry, paper on 
Cowles's process, 194 
second paper on Cowles's 

process, 196 
views on the aluminium 

industry, 42 
Hydrochloric acid, action of, on 

aluminium, 75 
Hydrogen, action on aluminium, 

reduction of aluminium -by, 


sulphide, action of, on alu- 
minium, 73 

use of, to purify aluminium, 

Imports of aluminium, 1870 to 

1884, 40 
Impurities, freeing of aluminium 

from, 240 

Instruments, mathematical, etc., 

suitability of aluminium 

bronze for, 268 

optical and portable electric, 

a suitable alloy for, 290 . 

Iodine, action on aluminium, 

Ireland, analysis of beauxite 

from, 47 

deposits of beauxite in, 46 
Iron, alloys of aluminium with, 


with aluminium, 209 
aluminium alloy, production 
of, :;-j:] 

Iron, aluminium alloy, used in 

the mitis process, 212 
coated with aluminium, 247 
crucibles, use of, in purify- 
ing aluminium, 241 
used by Rose, 106 
freeing of aluminium from, 

in commercial aluminium, 

estimation of, 307 
oxide, action on aluminium, 

reduction of aluminium by, 


sulphide by, 323 

Ivigtuk, Greenland, cryolite beds 
at, 48 

Jablochoff, reduction of sodium 

by, 131 
Javel, chemical works at, 28 

process for making alumin- 
ium as used at, 98 
Jeancon, J. A., patented process 
for depositing aluminium, 

Jewelry, aluminium, 247 
Johnson, double reaction method 

of, 184 
Jouet, Mr., analysis of beauxite 

by, 47 

j Joules, on the amalgamation of 
aluminium, 262 


Kagensbusch, electric process of, 

of Leeds, on reduction of 

aluminium by zinc, 218 
on reduction of aluminium 

by lead, 222 
Kamarsch, on the tensile strength 

of aluminium, 63 
Kerl and Stoh man, directions for 
soldering aluminium, 
by, 250 

historical r6sum6 by, 32 
on the melting of alu- 
minium, 236 
Klein Steinheim, analysis of 

beauxite from, 47 
Knight, remarks on aluminium 
bronze, 273 



Knowles, Sir F. C., cyanogen 
process of, 180 

Lang, I., analysis of beauxite' 
by, 47 

Langsdorff, analysis of beauxite 
from, 47 

Lauterborn, iron reduction, pro- 
cess of, 206 

Lauterborn's process for decom- 
posing cryolite tested, 

remark on, 317 

Lavoisier, first to suggest the 
existence of aluminium, 25 
Lazulite, formula of, 44 
Lead, action on an aluminium- 
tin alloy, 196 
alloys of aluminium with, 

deposition of, by aluminium, 

freeing of aluminium from, 

oxide, action on aluminium, 

reduction of aluminium by, 


sulphide by, 322 
Leaf aluminium, 245 
beating of, 57 
combustion of, 71 
decomposition of water 

by, 73 

Lechatelier, M., on the tensile 
strength of aluminium bronze, 

Lecoq de Boisbaudran, on alu- 
minium-gallium alloys, 300 
"Lessiveur methodique," 149 
Liebig, experiments to reduce 

aluminium, 93 
Lime, action of, on aluminium, 


crucibles for melting alu- 
minium, 36 

kiln , use of, to furnish car- 
bonic acid gas, 150 
phosphate of, action on alu- 
minium, 85 

Lining for crucibles, 123 
Liquation of aluminium, 238-240 

Lissajous, M., aluminium tuning 
fork made by, 63 

Litharge, action on aluminium, 

LIthia mica, formula of, 43 

Lockport, N. Y., Cowles Bros., 
plant at, 193-196 

Lbwig, experiments of, in pre- 
cipitating alumina, 151 

Lustre of aluminium, 55 

Mabery, Prof. Chas. F., official 
announcement of Cowles 
Bros.' process, 191-194 
on a new process for pro- 
ducing aluminium chlo- 
ride, 326 
views on the aluminium 

industry, 41 

Magnesia mica, formula of, 43 
Magnesium sulphide, production 

and reduction of, 312-317 
Magnetism of aluminium, 69 
Mal^tra, aluminium plant at 

Rouen, 29 
Malleability of aluminium, 57 

bronze, 267 

Mallet, directions for making 
chemically pure alumin- 
ium, 243 

on the resistance of pure alu- 
minium to alkalies, 77 
on the specific heat of pure 

aluminium, 68 
gravity of aluminium, 


Manganese, alloys of, with alu- 
minium, 302 
oxide, action on aluminium, 

reduction of aluminium by, 

Manufacture of aluminium 

bronze, 267 
Martin, Wm., aluminium plant 

at Rouen, 29 

Mat, production of, on alumin- 
ium, 54 
Mayer, L., analysis of beauxite 

by, 47 

Mel ting of aluminium scraps, 235 
point of aluminium, 65 



Mercury, action on aluminium, 

alloys of aluminium with, 

deposition of, by aluminium, 

Merle & Co., aluminium works j 

at Salindres, 28, 35 
Metallic aluminium not found : 

native, 43 

chlorides, action on alumin- 
ium, 85 
oxides, action on aluminium, 


Metallurgy of aluminium, 90, 257 
general remarks on the, 


of sodium, 130-143 
Metals, coating of, with alumin- 
ium, 231 

comparative density of, 64. 
electric conductivity of, ' 

thermal conductivity of, , 

plating on, with aluminium, 


precipitation of, from solu- 
tion by aluminium, 79 
relative affinity of sulphur 

for, 318 

Michel, experiment on alumin- 
ium and molybdenum, 302 
making of iron-aluminium 

allo\> by, 383 

Mierzinski, formulas of some alu- 
minium minerals as given 
by. 43 
general remarks on alloys 

of aluminium, 258 
on making aluminium 

bronze, 207 

on the manufacture of alu- 
minium-sodium chloride, 

on the melting of alumin- 
ium, 237 

on the reduction of alumin- 
ium by electricity, 226 
remark on the electrolysis of 
aqueous solutions o"f alu- 
minium salts, 2: 54 

Mierzinski, report on the present 
state of the alumina industry, 
Minargent, composition of, and 

method of making, 278 
Mineral soda, 105 
Mitis castings, 283 

ores suitable for, 205 
W. H. Wahl's remarks 

on, 326 

process, iron-aluminium al- 
loy used in the, 212 
Molten aluminium, viscidity of, 


Molybdenum, alloys of, with alu- 
minium, 302 

Monnier, Alfred, maker of 
aluminium at Camden, N. J., 

Morin and Deville, experiments 
in gilding and silverjng alu- 
minium, 80 
Morin, P., aluminium plant at 

Glaciere, 28 
experiments on gilding and 

silvering aluminium, 256 
improvements by, at Nan- 

terre, 28 

on the action of wine on alu- 
minium, 78 

on the specific heat of alu- 
minium, 68 
Morris. J.. carbon and carbon 

dioxide, method of, 187 
Mourey, method of soldering alu- 
minium, 248 
receipt for removing tarnish 

from aluminium, 54 
success in gilding and silver- 
ing aluminium, 80, 256 
Muriatic acid, action of, on alu- 
minium, 75 

Nanterre, aluminium works at, 

28, 35 
production of aluminium at, 

1859, 33 

reduction of cryolite at, 126* 
Napoleon III., liberality of, 28 
Native aluminium, 43 

sulphate of alumina, 305 
Neogen, composition of, 277 



Newcastle-on-Tyne, Bell Bros., 

aluminium works at, 33 
New York City, manufacture of 

sodium in, 139-141 
Nickel, alloys of aluminium with, 

aluminium plating by Frish- 

muth, 234 
experiment on aluminium 

aud tungsten, 302 
Niewerth, double reaction, 

method of, 185 
iron reduction, process of, 


Niewerth's nascent sodium pro- 
cess, 179 

process, remark on, 318 
Nitre, action of, on aluminium, 

purification of aluminium 

by, 241 

Nitric acid, action of, on alu- 
minium, 75 
Nitrogen, action on aluminium, 

alloys of, with aluminium, 


Normal School, Paris, experi- 
ments at the, 28 

Occurrence of aluminium in 

nature, 43-50 
Odor of aluminium, 56 
Oerstedt, first published paper 

on aluminium, 90 
isolation of aluminium by, 25 
Oerstedt's paper reviewed by 

Wohler, 91 
Ores of aluminium used by 

Cowles Bros., 205 
Organic acids, action of, on alu- 
minium, 78 

Orlowsky, A., on the relative 
affinity of sulphur for the 
metal, 318 

Orthoclase, formula of, 43 
Ostberg, Peter, inventor of mitis 

castings, 283 
remark on the reduction of 

aluminium by iron, 212 
Oxidation of aluminium, 71 
Oxide of barium, action on alu- 
minium, 87 

Oxide of copper, action on aln- 

minium, 87 

of iron, action on alumin- 
ium, 86 

of lead, action on alumin- 
ium, 86 

of manganese, action on alu- 
minium, 86 

of zinc, action on alumin- 
ium, 86 

sub, of aluminium, 26 
Oxides, metallic, action on alu- 
minium, 86 

Palais de ^Industrie, Paris, 1855, 
aluminium bar exhibited at, 

Paraffin, Wagner's use of, to pre- 
serve sodium, 138 

Paris Exhibition of 1855, alumin- 
ium objects presented at, 28 

Passemeutere, aluminium, 60 

Peligot, on cupelling alumin- 
ium, 71 

Pennsylvania Salt Co., importers 
of cryolite, 48 

Pens, suitability of aluminium 
bronze for, 272 

Percy, Dr., experiments in mak- 
ing aluminium bronze, 264 
reduction of cryolite prior to 
Rose, 115 

Petitjean, carburetted hydrogen, 
process of, 183 

Petitjean's process tested by Rei- 

Philadelphia, Col. Wm. Frish- 
inuth's aluminium works in, 

Phosphate of lime, action on 
aluminium, 85 

Phosphorized aluminium bronze, 

Phosphorus in aluminium, 126 

Photo-salts of aluminium, efforts 
to produce, 27 

Physical properties of alumin- 
ium, 51-70 

Plants, alumina never found in, 

Plating, aluminium, 231 
aluminium-nickel, 234 
with aluminium, 246 



Platinum, alloys of aluminium 

with. -'.'.' 
Poggendorff and Reiss on the 

nuiiriu'tisin of aluminium, 69 
Polish of aluminium, 55 
Porcelain crucibles, use of, for 
obtaining: aluminium, 22 > < 
imitation of, made with cryo- 
lite, 48 
Potash, action of, on aluminium, ! 


Production of aluminium bronze 
in the United States in 
by Col. Frishmuth,1883- 

"lS8t, 40 

in France, 18S2, 39 
in the United States in 

188"), 327 

Properties of aluminium sul- 
phide, 311, 316 

mica, formula of, 43 
Potassium, aluminium first iso- 
lated by the use of, 26 
amalgam, experiment with. 

by Gmelin. 26:} 
used in isolating alu- 
minium, 'J5 

and sodium, reduction to- 
gether of, 138 

carbonates, action on alu- 
minium, 8S 

chloride, action on alumin- 
ium, 85 
decomposition of, by 

electricity, 142 
cyanide as a reducing agent, 

reduction in the Bessemer 

converter, 208 
in the electric furnace, 

replaced by sodium by De- 


sulphate, action on alumin- 
. ium, 88 

vapor of, Davy's efforts to 
isolate aluminium with, 

Precious stones, formula} of, 44 
Precipitation of alumina at Sal- 

indres. UW 
of metals from solution by 

aluminium, 79 

Price of aluminium in 1857, 29 
in 1878, by the Socie.6 

Anonyme, 36 
in 1883-84, 39 
in October, 1886, 327 
Proctor, Bernard S., comparison 
of brass with aluminium bronze 
by. 271 


Pure aluminium, chemically, di- 
rections for making, 
only made by using so- 

dium, 42 
requirement for making, 

Purification of aluminium, 74, 

by nitre, 83 

Rammelsberg, on silicon in com- 

mericial aluminium, 52 
Rammelsberg, Prof., experi- 

ments in reducing cryolite, 103 
Rattle, baby, first article made 

of aluminium, 244 
Reduction furnace, Deville's, for 

sodium, 134 
for reducing aluminium 

by sodium, 169 
Gerhard's, 127 
of alumina by carbon in 

presence of copper, 309 
of aluminium at Salindres, 

by carbon, 188 

and carbon dioxide, 

by carburetted hydro- 

gen, ISii 
by copper, 212 
by cyanogen. 180 
by double reaction, 184 
by electricity. 
by feiTo-silicum, 206 
by hydrogen, 181 
by iron, 206 
by lead, 221 
by manganese, 222 
by other agents than so- 
dium, 180 



Reduction of aluminium by sili- ! 

con, 207 
by zinc, 214 
sulphide, 315, 322 
of sodium by Castner, 324 
under pressure, 179 
Reflectors, advantages of alu- 
minium for, 245 
Regnault, M., on the specific heat 

of aluminium, 68 
Reichel, paper on sulphides of 
aluminium and magnesium, j 

Reinar, G. W., on the reduction j 
of aluminium by carbon, 189 ; 
Reiss and Poggendorff, on the 
magnetism of aluminium, 69 i 
Retorts for reducing sodium, 

Retzlaff, analysis of beauxite by, i 

Ricarde-Seaver, Major, views on j 

aluminium, 37 
Rollins: of aluminium, 57 
Rose, H., paper on reduction of j 

cryolite, 103-115 
Rouen, aluminium works near, I 

29, 83 

process used at, 124 
Rousseau Bros., aluminium 

works at Glaciere, 28 
Ruby, formula of, 44 

St. Austel, supposed discovery of j 

native aluminium at, 43 
Salindres, aluminium works at, 

28, 35 

cost of aluminium at, 172 
manufacture of aluminium 

at, 158-174 
of aluminium-sodium j 

chloride at, 154-166 
Salt, common, action on alumin- 
ium, 85 

Salts, metallic, action of solu- . 
tions of, on aluminium, 79 | 
Sapphire, formula of, 44 
Sartorius of Gottingen, first j 
maker of aluminium balance I 
beams, 35 

Sauvage, F. H., inventor of neo- ' 
gen, 277 

Schank, washing apparatus of. 

Schnitzer, analysis of beauxite 

by, 47 
Schwarz, improvenent on Mou- 

rey's solders by, 249 
Scraps, aluminium, melting of, 

melting of, by Col. 

Frishmuth, 39 

Sellers, Mr., of Philadelphia, on 
the use of aluminium in cast- 
ing iron, 284 

Senct, M. L., on depositing alu- 
minium by electricity, 233 
Sevrard, M., success of, in ve 

neeriug aluminium, 253 
Seymour, Fred. J., patent for the 
reduction of aluminium 
by zinc, 218 
second patent of, 220 
Shaw, T., patented phosphor 

aluminium bronze, 279 
Siemens's furnace, used in reduc- 
ing sodium, 135 
Siemens, Sir Wm., melting of 

steel with electricity, 194 
Silicates, action of, on alumin- 
ium, 84 

of aluminium, formulae of, 43 
Siliceous aluminium, 238 

on the gases evolved 

du ring sol ution of, 260 

Silicon, alloys of aluminium 

with, 259 
aluminium bronze, 205 

extraordinary strength 

of, 280 
bronze manufactured by M. 

Evrard, 211 
crystallized, 260 
disengagement of, as si lieu- 
retted hydrogen in dissolv- 
ing aluminium, 76 
facilitates the oxidation of 

aluminium, 71 
freeing of aluminium from, 

243 - 
its state of combination in 

aluminium, 52 
use of, to reduce aluminium, 



Silieu rotted hydrogen, formation 
of, 011 dissolving aluminium, 
Silver, allovs of aluminium with, 

295 " 

aluminium, 297 
comparative value with alu- 
minium, 65 
deposition of, by aluminium. 

from clay, exhibited at Paris, 

1855, 34 
sulphide, decomposition of. 

by aluminium. 74 
Silvering 1 of aluminium, 256 

difficulty in, 80 
Smith, Dr., patents on reduction 

of aluminium, 221 
Soci:e Anonyme de 1'alumin- 

ium, 35 

prices of aluminium and 

aluminium bronze, 36 

Soda, action of, on aluminium, 


mica, formula of, 43 
mineral, 105 

Sodium, alloys of, with alumin- 
ium, 303 
aluminate, precipitation of, 

by Lowig, 151 

amount necessary to reduce 
aluminium from cryolite, 
and potassium, reduction 

together of, 138 
calcination furnace, 133 
carbonates, action on alu- 
minium, 88 

chloride, action on alumin- 
ium, 85 
decomposition of, by 

electricity, 142 
cvanide as a reducing agent, 
Gerhard's furnace to prevent 

loss of, 120 
great reduction of its price 

in 1859, 27 

its manufacture, 130-143 
manufacture in New York 

City, 1886, 139-141 
mixture for reduction, 132 

Sodium, nascent, as a reducing 

agent, 179 
preservation of, by Wagner's 

method. 138 
reaction for the reduction of, 


reduction by Briinner, 131 
by Castner, 139 

additional details 

of, 324 

by Curaudau, 131 
by Davy, 131 
by electricity, 142 
by Gay Lussac, 131 
by Jablochoff, 142 
by Thenard, 131 
furnace for, 134 
in the Bessemer conver- 
ter, 208 
in the electric furnace, 

of aluminium by other 

agents than, 180 
of the double chloride 

by, 168 
process, the perfection 

of the, 171 
substituted for potassium by 

Deville, 27 

sulphate, action on alumin- 
ium, 88 
temperature of the reduction 

of, 137 
use of chalk in the reduction 

of, 133 
vapor process as used by 

Deville, 100 
of Frishmuth, 178 
Weldon's calculation of the 

cost of, 139 

Soils, alumina the base of, 43 
Soldering liquor for aluminium, 


of aluminium, 247-253 
Solders for aluminium, 248-251 

bronze, 279 

Sonorousness of aluminium, 63 
Spear, Mr. W. B., in connection 
with native sulphate of alu- 
mina, 305 

Specht, on the reduction of alu- 
minium by /inc, 218 



Specific heat of aluminium, 68 
gravity of aluminium, 64 

bronze, 271 

of commercial alumin- 
ium, 307 
Sprague, remarks on electrolysis 

of aluminium salts, 232 
Spruce, Mr., analysis of beauxite 

by, 47 

Stamping of aluminium, 58 
Stearic acid used for burnishing 

aluminium, 55 
Steel, alloys with aluminium, 


Stocker, on native aluminium, 43 
Stoddart and Faraday, analysis 

of Bombay wootz, 283 
Stones, precious, formulae of, 44 
Strange, Mr., experiments with 

aluminium bronze, 273 
Strength, compressive, of alu- 
minium, 62 

aluminium bronze, 272 
tensile, of aluminium, 62, 63 
of aluminium bronze, 

266, 267, 270, 276 
of aluminium-silicon 

bronze, 205 

transverse, of aluminium, 62 
Sulphate of alumina, decomposi- 
tion of, by electricity, 
231, 233 
native, 305 
Tilghman's process for 

decomposing, 144 
of potash, action on alu- 
minium, 88 

of soda, action on alumin- 
ium, 88 
Sulphide appearance, properties 

and analysis of, 311 
a practical process for 

producing, 321 
experiments on produc- 
ing, 318 

on reducing, 322 
production and reduc- 
tion of, 309-324 
reduction of, by Co- 
menge's method, 
by manganese, 222 

Sulphide appearance, reduction 
of, by Petitjean's me- 
thod, 183 

remark by Than on, 314 
researches of Fremy on, 


of Reichel, 312 
carbon di-, use of, for making 
aluminium chloride, 

use of, for making alu- 
minium sulphide, 310 
Sulphides of aluminium and 
magnesium, Reichel's 
paper on, 312-317 
Sulphur, action on aluminium, 

73, 88 
its relative affinitv for. the 

metals, 318 
Sulphuretted hydrogen, action 

of, on aluminium, 73 
Sulphuric acid, action of, on 

aluminium, 74 

Surgery, use of aluminium in, 87 
Sweat, action on aluminium, 87 
Syndicate, an English, to control 
patents on aluminium, 39 

Tanks, precipitating, 152 
Tarnish, Mourey's receipt for re- 
moving, from aluminium, 54 
Tarnishing of aluminium, cause 

of, 240 

Tartaric acid, action of, on alu- 
minium, 78 

Taste of aluminium, 57 
Taylor, W. J., calculated cost of 

aluminium, 32 

Telegraph wire, aluminium, 243 
Temperature necessary to reduce 

sodium, 137 

Tempering of aluminium, 58 
Tenacity of aluminium, 61 
Tensile strength of aluminium, 

62, 63 
of aluminium bronze, 

266, 267, 270, 276 
of aluminium-silicon 

bronze, 205 

Than, remark by, on the forma- 
tion of aluminium sulphide, 



Thenard, reduction of sodium 

by, 131 

Thermal, conductivity of alu- 
minium, 67 
Thomas and Tilly, process for 

aluminium plating, 231 
Thompson, J. B., deposition of 
aluminium from solution, 231 
Thompson, W. P., paper on the 

Cowles's process, 197-205 
Thompson, W. P., reduction of 

aluminium by, 207 
Thomson's calcination furnace 

for cryolite, 146 

" Tiers Argent/' an alloy of alu- 
minium and silver, 297 
Tilghman's process for decom- 
posing sulphate of alumina, 

Tin, alloy of aluminium and, 196 
alloys of aluminium with, 

aluminium alloy, action of 

lead on, 196 
production of. 322 
its injurious effects in food, 

plate, aluminium plate a 

substitute for, 247 
reduction of aluminium sul- 
phide by, 322 
Titanum, alloys of aluminium 

with, 301 
Tissier Bros., Deville's charges 

against, 28 

experiments on solder- 
ing aluminium, 248 
history of their works, 29 
process, 124 
"Recherches sur 1'Alu- 

minium," 1858, 28 
Tissier, on the amalgamation of 

aluminium, 262 
Topaz, formula of, 44 
Tracheotomy, aluminium tube 

used in, 87 
Tungsten, alloys of aluminium 

with, 302 

Tuning forks, aluminium, 63 
Turquois, formula of, 44 

Uses of aluminium, 243-247 

Usiglio, manager of the works at 
Saliudres, 33 

Vanadium, occurrence in beaux- 
ite, 46 

Vangeois, first maker of alumin- 
ium wire, 60 

Veneering with aluminium, 253 

Vielle Mcntagne Zinc Works, on 
the use of retorts from, 288 

Viscidity of molten aluminium, 

Volatilization of aluminium, 66 

Wagner, 0., analysis of beauxite 

by, 47 
Wahl, W. H., remarks on mitis 

castings, 326 
Wasellite, formula of, 44 
Washing apparatus, 149 

used at Salindres, 161 
methodical, 149 

Washington monument, cast- 
aluminium tip of, 39 
composition of the alu- 
minium in the tip of, 
description of the apex 

of, 40 
Water, action of, on aluminium, 


sulphide, 311, 317 
decomposition of, by alu- 
minium leaf, 73 
Watts's Dictionary, Frishmuth's 

process mentioned in, 42 
Watts, on the use of cryolite for 

producing aluminium, 127 
Webster, aluminium works of, 

at Birmingham, 36 
improvement of, in making 
aluminium sodium double 
chloride, 154 

James, patented alloy of, 278 
process of, only one used in 

England, 42 
Webster's patent, 175 
process, 173-177 

Wedding. M., remarks on Bas- 
set's zinc process, 217 
Weldon, W., of Burstow, Eng- 
land, manganese process of, 222 



Wertheim, on the elasticity of 

aluminium, 61 

Wilde, A. E., on reducing alu- 
minium by lead, 221 
Winckler, Dr. Clemens, histori- 
cal retrospect to 1879, 
on coating metals with 

aluminium, 254 
remarks on electrolysis 
of aluminium salts, 

Wine, acid action of, on alumin- 
ium, 78 
Wire, aluminium, drawing of, 60 

strength of, 63 
Wirz & Co., Berlin, stoppage of 

their aluminium works, 35 
Wochein, analysis of beauxite 

from, 47 
Wocheinite, local .name for 

beauxite, 46 

Wohler and Buff, on the solution 
of siliceous aluminium, 

and Deville, on the extrac- 
tion of Boron, 300 
Deville's opinion of, 31 
discovery of aluminium, 

1827, 26, 91 

experiments to obtain alu- 
minium amalgam, 25 
first paper of, 91 
improvement on Deville's 

cryolite process, 126 
method used in 1845, 26 
observation on melting alu- 
minium with a blowpipe, 

Wohler and Buff on the resist- 
ance of aluminium to aqua 
ammonia, 78 
review of Oerstedt's paper, 


second paper of, 93 
Working of aluminium, 235-257 
Works, aluminium, at Amfre- 
ville, near Rouen, 29, 

124, 128 

at Battersea, London, 33 
at Berlin, 35 
at Birmingham, England, 36, 


at Camden, N. J., 31 
at Cleveland, Ohio, 4.1, 189 
at Glacidre, 28, 98 
at Javel, 28, 98 
at Nanterre, 28, 35, 126, 128 
at Newcastle-on-Tyne, 33 
at Philadelphia, 37, 178 
at Salindres, 28, 33, 128, 168 
in England, 33, 35, 42 
in France, 35, 128 
in Germany, 33, 35 

Zinc, alloys of aluminium with, 

deposition of, by aluminium, 

expelling from aluminium 

by heat, 218 
freeing of aluminium from, 

oxide, action on aluminium, 

reduction of aluminium by, 




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DEC 1 1956 


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MAY 1 o 1966 3 3 

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