June l, 1865.] THE TECHNOLOGIST. 



ON MAGNESIUM. 489 



Bussy is sometimes credited with the discovery of magnesium, but 

 though that honour is unquestionably Davy's, he was certainly the 

 first to exhibit it in anything beyond microscopic quantities, and to 

 describe its properties. 



With Bussy progress ceased for another series of years. Becquerel, 

 by electrolysis, from a solution of the chloride of magnesium, procured 

 the metal in minute octohedral crystals. Bunsen, likewise by electro- 

 lysis, obtained the metal, and further modified Bussy's process by adding 

 chloride of sodium or of potassium to the anhydrous chloride of 

 magnesium. Matthiessen in turn tried to improve upon Bunsen by 

 adding chloride of ammonium, also reducing the compound by electro- 

 lysis. He afterwards succeeded in pressing some grains of magnesium 

 into wire. 



It was reserved, however, for Deville and Caron to make the first 

 grand advance on the labours of Bussy. They, about 1856, effected the 

 reduction of the chloride of magnesium by sodium in clay crucibles, 

 using the fluoride of calcium as a flux ; and so obtained magnesium in 

 larger quantities than any of their predecessors. But their chief dis- 

 covery was the volatility of the metal ; they distilled a few grammes at 

 a time in a gas carbon retort tube enclosed in a porcelain tube.* 



So far magnesium had been produced on a laboratory scale ; none of 

 the methods made any pretence to commercial application. In 1859, 

 M. Bunsen, of Heidelberg, and Professor Boscoe, of Manchester, after a 

 variety of experiments, published their opinion of the high value of 

 magnesium as a source of light for photographic purposes owing to the 

 close affinity of its chemical properties to those of sun-light ; and 

 offered at the same time some excellent suggestions as to the mode 

 of its combustion — suggestions which have since been wrought into 

 practice. 



The memoir of Bunsen and Roscoe was read by Mr. Edward 

 Sonstadt — a young Englishman with a name derived from Swedish 

 ancestry — and it set him thinking whether it would not be possible to 

 make magnesium cheap enough for at least some practical purposes. 

 The ore was abundant. Surely some means might be devised for 

 releasing the silvery treasure from the elements which held it in 

 obscurity and idleness ! 



The question started, was quickly attacked with vigour, pertinacity, 

 and ingenuity. For many months, day after day, far into the night, 

 and often until the dawning of the morning, did Sonstadt, without 

 cessation, first in Nottingham, and subsequently at Loughborough, 

 strive, through multitudinous and costly experiments, to compass his 

 end. In November, 1862, he had so far succeeded, that he felt 



* MM. Deville and Caron's labours are described with that exquisite clearness 

 •which is peculiarly French, in the "Comptes Rendus" of the 27th February, 

 1857, page 394, and with enlarged experience in the " Annales de Chiinie et de 

 Physique," 1863, vol. lxvii., page 347. 



