NATURE 



537 



THURSDAY, OCTOBER 2, 1890. 



THE METAL OF THE FUTURE. 

 Aluminium : its History, Occurrence, Properties, Metal- 

 lurgy, and Applications, including its Alloys. By Jos. 

 W. Richards. (London : Sampson Low and Co., Ltd., 

 1890.) 



A S the recent improvements in the manufacture of 

 -^ *- aluminium have been so great as to enable it to be 

 bought now at one-tenth the price it was only three years 

 ago, and as its uses, especially in its alloys, are becoming 

 constantly more extended and varied, a somewhat detailed 

 review may be of service in directing attention to this, 

 the latest book on the subject. It is intended by the 

 author, who is instructor in metallurgy in Lehigh 

 University, to lay before the general public as well as 

 before metallurgists a full and accurate account of the 

 aluminium industry as it exists at the present time. To 

 do this, the author has found it necessary to make such 

 numerous and extensive additions to the first edition, 

 that the present volume may almost be regarded as a 

 new book. 



Passing in review the various parts of the book, we come 

 first to an admirable resume, of 27 pages, of the 

 history of the progress made in reducing aluminium 

 metal ; it contains much interesting information, not easily 

 obtainable elsewhere, describing the founding of the 

 various works for this manufacture from the time of 

 Deville to the present electrical processes of Cowles, of 

 Lockport, New York ; of Hall, of Pittsburg ; and of 

 Heroult, of Neuhausen, Switzerland. The affairs of 

 Frishmuth, of Philadelphia, here mentioned, may serve 

 as a warning to those too ready to believe reports of 

 success from enthusiasts or from the inventors of secret 

 processes. 



Chapter ii., of 7 pages, deals with the occurrence of 

 the compounds of aluminium in Nature. It may be in- 

 teresting to remind the reader of the existence of several 

 precious stones that contain aluminium, but a list of 

 " some other compounds occurring frequently " is surely 

 very misleading when it contains the minerals turquoise, 

 lazulite, wavellite, topaz, and even cryolite ; these ought 

 to have been replaced by such minerals as the sodium- 

 and potassium-felspars, hornblende, augite, mica, kaolin, 

 &c. These common aluminium minerals are described, 

 curiously enough, however, in the chapter dealing with 

 the artificial preparation of aluminium compounds. The 

 statement "that aluminium has never been found in 

 animals or plants " requires correction. The description 

 of beauxite is accompanied by many analyses ; but that 

 of cryolite, which is directly used in the manufacture of 

 aluminium, is accompanied by an incorrectly calculated 

 percentage composition, and the one statement that "the 

 so-called pure article was found by Prof. Rogers, of Mil- 

 waukee, to contain 2 per cent, of silica and i per cent, of 

 iron," although further details are to be found on several 

 other pages of the book. 



Chapters iii. and iv., of 31 and 13 pages, deal with the 



physical and chemical properties of aluminium. A list is 



given of analyses, and an account of various specimens of 



■commercial metal, showing the amount of the impurities, 



NO. 1092, VOL. 42] 



iron and silicon, that may be contained, and the feffect on 

 the physical properties is mentioned. The chapter on 

 the chemical properties concludes with a paragraph headed 

 "General Observations on the Properties of Aluminium" ; 

 this, being a quotation from Deville's general theoretical 

 considerations, is very much behind the time indeed, and 

 should be replaced by observations made with respect to 

 Mendeleeff's classification of the elements, and coupled to 

 the general considerations on the " structure of aluminium 

 compounds" that introduces the next chapter. 



Chapter v. describes generally the properties and pre- 

 paration of aluminium compounds, but requires some 

 alterations ; thus, on p. 86 we read, " Alumina forms no 

 carbonate," and p. 103 is a paragraph headed "Aluminium 

 Carbonate," describing the preparation of the compound 

 AI2O3.CO2 ; and again, p. 88, we find diaspore is Al._jO3.H2O, 

 beauxite is AI2O3.2H2O, and gibbsite is Al26;j.3H20, 

 whereas on p. 47 it is said that " beauxite is a combin- 

 ation between diaspor, AI2O3.3H2O, and brown hematite, 

 Fe203.3H20," and on the same page is also found 

 " Diaspore, H2AI2O4." We must certainly disagree with 

 the names " aluminium-ammonium chloride " for the 

 substance AI2CI8.3NH3, and "aluminium fluorhydrate" 

 for AljFe.yHgO, and also think that the description of 

 some dozen substances as the double chlorides of 

 aluminium and sulphur, phosphorus and selenium, the 

 above ammonia compound and the selenide and selenite 

 of aluminium, might have been entirely omitted, and 

 the space devoted with advantage to a more detailed 

 description of the really important compounds. 



Chapter vi., of 29 pages, is a well-written account 

 of the "Preparation of Aluminium Compounds for 

 Reduction," and describes the preparation of alumina 

 from crude sulphates, from beauxite and from cryolite, 

 the preparation of aluminium chloride, and aluminium 

 sodium chloride, and the preparation of artificial cryolite 

 and of aluminium fluoride, and also that of the sulphide 

 of aluminium. The numerous processes here described 

 give one much food for thought and comparison, and 

 though no author is really responsible for the statements 

 of others which he may introduce, yet where the state- 

 ments of two authorities do not agree, the disagreement 

 should be mentioned and suggestions made to explain the 

 cause of it. Two cases may be cited. On pp. 113 and 

 118, analyses are given of alumina precipitated by car- 

 bonic acid from sodium aluminate solutions : the one 

 shows 2-5 and the other 20 per cent, of sodium car- 

 bonate. Again, on p. 121 we find the method of Sauer- 

 wein for preparing alumina from cryolite, viz., 



AljFe.eNaF -\- A)20.j.3Na20 + 6H2O = 2(Al203.3HaO) 



+ i2NaF ; 

 while on p. 137 is described the very reverse reaction, a 

 method of Berzelius for preparing cryolite from alumina, 

 viz., 



2AI2O3.3H2O -f- i2NaF = AlgFo.eNaF -|- Al203.3Na.p 



+ 3H2O 

 (this last item is a mistake for 6H2O). 



Chapter vii., of 39 pages, describes " The Manu- 

 facture of Sodium," giving a full account of the older 

 processes, and also of the recent ones of Castner and 

 Netto, in which not sodium carbonate, but hydrate, is 

 reduced by carbon at a red heat. There is also referetice 



