METALS. 
63 
“ slag wool/’ Some interesting specimens of old slag from the 
Weald carry us back to the days when iron was smelted in 
Kent and Sussex. A series of specimens in this Case illustrates* 
a process used at one time by Messrs. Chance, of Birmingham* 
for melting the Rowley rag, a basaltic rock occurring in South 
Staffordshire, and casting it in moulds for tiles and architectural 
ornaments. It is interesting to note, from these specimens, that 
when the product cooled rapidly it formed a vitreous mass like 
obsidian, whereas if cooled slowly it soldified as a hard stony 
substance. 
Swedish Iron and Steel, Copper, &c. Cases Nos . 15 and 18. 
It is well known that iron of a very superior quality, much 
valued for steel manufacture, has long been produced from the 
iron ores of Sweden. These consist chiefly of the magnetic and 
red oxides, which are classed together as “ mountain ores/' to 
distinguish them from the brown oxides, which occur in the 
shape of “lake- ” and “bog-ores,” and yield an inferior kind of 
iron employed chiefly for castings. The mountain-ores are 
calcined usually in kilns heated by the waste gases from the 
blast furnace, and are smelted exclusively with charcoal. It is 
to the employment of this fuel, and to the freedom of the ores 
from phosphorus, that the Swedish iron owes its superiority. 
The greater part of the pig iron is converted into malleable iron 
in refineries, or hearths, heated with charcoal. 
The Table Case No. 15 is entirely devoted to specimens of 
Swedish iron and steel, and a large part of No. 18 also contains 
examples of these metals and of the ores from which they are 
produced. But the visitor will also find in Case 18 a number of 
other Swedish metallurgical products, including a series illus- 
trating the extraction of nickel at Klefva in Smaland ; the 
smelting of lead at Sala and the production of copper at Falun. 
The mines, or rather open workings, at Falun, in Dalecarlia, are 
of great antiquity, and yield large quantities of copper - and 
iron-pyrites, but the workings are of much less importance now 
than they were formerly. 
Swords and Gun- Barrels. Case No. 13. 
Swords . — The oriental sword blades have always been cele- 
brated, and their superior character has been referred to the 
excellent iron ores which are obtained in various parts of Asia, 
and to the reduction of those ores by charcoal. The finest 
oriental sabres are those, professedly of great antiquity, pre- 
sumed to have been made at Damascus in Syria, at Ispahan m 
Persia, and at Cairo in Egypt. The characteristics ascribed to 
the real Damascus blades are, extraordinary keenness of edge, 
great flexibility of substance, a singular grain of fleckiness 
always observable on the surface, and a peculiar musky odour 
