March, 1903.] 



KNOWLEDGE. 



61 



%ttttv . 



[The Editors do not bold themselves responsible for the opinions 

 or statements of correspondents.] 



DID THE ROMANS KNOW ALUMINIUM r 



TO THE EDITORS OF KNOWLEDGE. 



Sirs, — The origin of the legend (xee Knowledge, 

 September, 1902, p. 20-i) whieli may lead us to suppose 

 that the Romans may have known aluminium is to be 

 traced to a passage of Petroiiius' " Satyricon," Chapter 

 LI., (1) of which the following is a translation : — 



" However, a workman succeeded in making a cup of a 

 kind of glass which could not be broken. Admitted to the 

 presence of the Emperor, he presented it to him, then, 

 begging to have it handed back to him, he threw it down 

 en the stone tloor. The Emperor could not help shuddering, 

 but the workman picked it up all dented, as would have 

 been the case if made of bronze, took out a small hammer 

 from his pocket, and, without being in the least concerned, 

 tlioi'oughly repaii'ed the damage. After this, he already 

 thought himself un Jupiter's throne, especially when he 

 heard himself being asked : ' Is there any man acquainted 

 with thy process ? Think.' ' No one.' The Emperor 

 thereupon ordered his head to be cut off, for if the thing 

 once got to be known, gold and sand would have the same 

 value for us." 



Petronius' account was written about a.d. 60. Pliny the 

 Elder (2) (Hist. Naturalis I. XXXVI., c. 26) succinctly 

 records it, perhaps after Petronius, without seeming to 

 give it very much credit. His text dates from a.d. 75. 



According to Dion Cassius (o), Roman History (written 

 about A.D. 220) (R.R. lib. LVII., c. 21), the anecdote would 

 be posterior to a.d. 22. 



Isidorus of Sevilla (4), who lived in the Vllth century 

 of the Christian era, and who is known especially for his 

 " Etymologies," relates Petronius' account, while somewhat 

 modifying it. 



In his Ijook of Etymologies (16th book, chap. 16), the 

 following is in effect to be found: — 



'■ It is said that under the reign of Tiberius a workman 

 had iuventi'd a vitreous combination (vitri temperameiitum) 

 which was flexible and ductile." 



He then recounts substantially the same anecdote as 

 that I have quoted from Petronius. . 



To sum up, the anecdote which may give occasion to 

 sup[)ose that aluminium was known in the time of the 

 Romans must date from about a.d. 2.5 (according to Dion 

 Cassius) at Rome. 



We kuow it : — 



1st. From Petronius' Sat. .51 (about a.d. 60), a picturesque 

 anecdote. 



2nd. From Pliny the Elder, H. N. XXXVI., 26 (about 

 A.D. 75), a mere mention. 



ord. From Dion Cassius, H. Rom. 57, 21 (about a.d. 

 220), a mere mention. 



■tth. From Isidoi'us of Sevilla, Etym. XVI., 15, 6 (about 

 A.I). 600), an anecdote similar to that of Petronius. 



With the exception of the last of these accounts, it is 

 clearly a question of an " unbreakable glass " ; and, in 

 fact, Petronius' anecdote has been attributed to the manu- 

 facture of annealed glass. 



If we refer to the passage in Petronius, we will notice 

 that the author has put the account into Trymalcion's 

 mouth, following upon another account aboutthe origin 

 of the Corinthian bronze, which is evidently absurd. In 

 fact, Petronius wanted to make Tryuialciou appear 

 ridiculous, and his commentators (Panckouke Translation) 

 point out that the legend of ductile glass was a tale of 

 anti(iuity which no longer found any belief a( the beginning 

 of (he Christian era 



And now we can ask ourselves the question — supposing 

 the anecdote related by Petronius is serious — in what 

 manner could Tiberius' workman have obtained aluminium r 



A few years after the discovery of aluminium, a memo- 

 randum from M. Chapelle appeared in the Reports of the 

 Academy of Sciences, tending to prove that by heating a 

 mixture of chloride of sodium, clay, and charcoal, a multi- 

 tude of metallic globules are obtained, which would be 

 aluminium. 



Good Isidorus of Sevilla, who after his account gives 

 such an ingenuous note, will not accuse us of being naive 

 if we say that, given its origin, this note may be taken 

 seriously. 



In the course of work which has led me to obtain blue 

 glasses with base of chromium, I had occasion to make an 

 interesting experiment. In a paper which the " Berichte 

 der Deuts.che Chemische Gesellschaft " (1898) have 

 inserted in its entirety, and to which the " Chemical 

 News" (5) (Vol. 78, No. 2021, 1898) has likewise given 

 ample hospitality, I have published the following 

 experiment : — 



I have heated .in a fireclay crucible lined with charcoal 

 a mixture of borax and alumina with a small quantity of 

 dichromate of potassium and a C|uantity of silica equal to 

 a two-fifth part of the alumina used, a metallic pellicle was 

 formed, consisting for the most part of aluminium. 



It is well known that boric acid is plentiful in Italy, 

 since for a long time the greatest part of the borax 

 delivered for the purposes of industry came from the 

 lagoons of Tuscany. Therefore, it is not impossible that 

 the three bodies — boric acid, potassium, clay — which under 

 the influence of charcoal, perhaps favoured by small quan- 

 tities of foreign substances, may give aluminium, might 

 have been brought together. 



However, I have not, any more than Tiberius' workman, 

 the pretension of having obtained pure aluminium by this 

 process ; but it appears to me interesting to compare this 

 result of an experiment, which interested a few chemists 

 at the time I made it known, with the question raised by 

 your correspondent. 



At any rate, the question deserved to be asked, and here 

 the legend is indeed of more worth than many well estab- 

 lished truths, since it leads one to make curious experi- 

 ments ; as for me, I am indebted to it for the discovery of 

 the reduction of alumina liy aluminium, as well as that of 

 the extraordinarily energetic combustion of a mixture of 

 water and pulverised aluminium, which is set alight by 

 means of a little dry powdered magnesium. 

 A. DuBoix. 

 Jhcteur ex-Sciences Pliysiijiies, Maltrr de Conferences 

 a III Fdcult'' (h's Scitnces de Grenoble. 



Siii GEORGE STOKES. 

 By the death on February 1st of Sir George Gabriel 

 Stokes this country lost one of the most eminent men of 

 science that it has ever jiossessed, and the gi-eatest mathe- 

 matician iif the day. 



He was born on August 13tb, 1819, at Skreen, Co. Sligo, 

 his parents being the Rev. Gabriel Stokes, the Rector of 

 the parish, and Elizabeth, daughter of the Rev. John 

 Haughton, Rector of Kilrea. When thirteen years of age 

 he wns sent to Dublin to be educated at the school of the 

 Rev. R. H. Wahl, d.d., from which he passed in 1835 to 

 Bristol College. At the age of eighteen he entered Pembroke 

 College. Cambridge, where in IS-il he graduated as Senior 

 Wrangler and First Smith's Prizeman. He became Fellow 



