16 
ON MAGNESIUM. 
the chlorine of the acid, forming the desired product—chloride of magnesium, but in 
solution. 
The water is next evaporated from the salt. The liquor is poured into broad open 
pans, which are placed over stoves. When the drying is sufficiently advanced, the salt 
is collected into a crucible and subjected to heat until perfectly melted and the last 
traces of water driven off, when it is stowed away in air-tight vessels. 
II. In the second stage, that curious metal, sodium, used likewise in the reduction of 
aluminium, comes into play. Common table salt is sodium plus chlorine; released 
from chlorine we have sodium. It is a white metal, but quickly grows dim on exposure 
to the moisture of the atmosphere. If cast upon water it floats and burns fiercely, 
almost like potassium. Such is its affinity for oxygen, that it has to be kept in air¬ 
tight vessels or under oil. It may be cut with a knife, somewhat like tough cheese. 
In a crucible are deposited five parts of the dry chloride of ’ ec gnesium, with one part 
of sodium. The crucible is covered and heated to redne J on the chlorine deserts 
the magnesium and flies over to the sodium. The crucible is allowed to cool, and its 
contents removed in block, which, when broken up, reveals magnesium in nuggets of 
various sizes and shapes, like eggs, nuts, buttons, and in minute granules. This product 
is styled crude magnesium. 
III. The distillation of the crude magnesium is effected in a crucible through which 
a tube ascends to within an inch of the lid. The tube opens at the bottom into an iron 
box placed beneath the bars of the furnace, so that it nu be kept cool. The crucible 
is filled with the crude metal to the level of the mouth of the tube, the lid is carefully 
luted down, and the atmospheric air expelled by the injection of hydrogen. As the 
crucible becomes heated, the magnesium rises in vapour freed from any impurities, and 
descends through the upright tube in the centre into the box below, where, on the com¬ 
pletion of the operation, it is found in the form of a mountain of drippings. It is sub¬ 
sequently melted, and cast into ingots, or into any other form that may be desired. 
In this broad sketch of the process of manufacture, the reader will perceive how fully 
Mr. Sonstadt’s ideal has been realized. Scarcely a month elapses in which some detail 
is not reduced to greater simplicity, and some new economy discovered in the works of 
the Magnesium Metal Company. The new art has made great progress since its esta¬ 
blishment; experience suggests constant improvements: as the old copy-head runs— 
Practice makes perfect. 
When the Magnesium Company commenced manufacturing, the question presented 
itself, In what form should the metal be offered to the public? As there was no known 
use for it except as a light, it was determined to vend it in the form of wire; but here 
arose a difficulty—How to make wire. The metal was not ductile, and could not, like 
iron or copper, be drawn out. Dr. Matthiessen and others had pressed small quantities 
into wire, but when experiments were made on a large scale, the magnesium was found 
capricious; sometimes it worked readily, but at others it resisted enormous pressure, and 
the rams broke down under the strain. Mr. William Mather, of Salford, had taken the 
matter in hand, and with admirable resolution declined to be baffled; through costly 
disasters he persevered, tried, and tried again, and finally overcame. Now, by machinery 
of his contrivance, the metal is pressed into wire of various thickness, and a spectator 
might wonder, as the silver threads stream forth, how that which now seems so easy 
should have cost such pains. Mr. Mather improved on the wire by flattening it into 
ribbons, in which form, as a larger surface is exposed to the air, combustion takes place 
more completely. Mr. Mather likewise made the first lamp for burning magnesium. 
In it the end of the wire or ribbon was presented to the flame of a spirit-lamp, to ensure 
perfect combustion. As the wire burnt, it was paid out by hand from a reel, and pro¬ 
pelled between rollers through a tube, which conducted it to the flame. A concave 
reflector diffused the light forwards, and afforded shade to the eyes of the operator. 
To few could the introduction of the new metal to commerce yield such lively satis¬ 
faction as Professor Roscoe, whose hint had been, as it were, the spark which set Mr. 
Sonstadt’s energy afire. It was Dr. Roscoe’s lot, moreover, to introduce magnesium to 
the scientific public. In doing so, he was fortunate in having the assistance of Mr. 
Brothers, of Manchester, who, in the spring of 1864, was the first to take a photograph 
by the magnesium light. At the Royal Institution in May, last year, Professor Roscoe 
delivered a lecture on light, and among his illustrative experiments, burned some mag¬ 
nesium, and calling forth Professor Faraday from the audience, had him photographed 
