607 
evidently formed part of the rude structure which had served 
as a substitute for our modern blast furnaces. 
It now became apparent that we stood on the site of an 
ancient "bloomery," though, on inquiry of the inhabitants 
of the district, we were unable to gain any information, 
historical or traditional, tending to confirm the opinion that 
the manufacture of iron had at any time been carried on in 
the district. 
The slag referred to is of a blackish colour, is somewhat 
vesicular, has a vitreous fracture, fuses without much difficulty 
before the blow -pipe, and on analysis yielded to me the 
following results : — 
Silicic Acid 29-60 
Alumina 5 - 60 
Lime 280 
Magnesia 3*72 
Protoxide of Iron 56 - 52 
Sulphide of Calcium 1*00 
Loss, with traces of Manganese and Phos- 
phoric Acid *7G 
100-00 
The above analysis represents a slag which is essentially 
a double silicate of alumina and protoxide of iron, together 
with a little lime and magnesia. The oxygen in the com- 
bined bases considerably exceeds that in the silicic acid, a 
fact which is the reverse of that generally observed in the 
analysis of modern iron slags ; experience having shewn that 
the slag possessed of the highest degree of fusibility is that 
in which the proportion of oxygen in the acid is exactly 
double that in the base. 
The composition of the Lochgoil slag is sufficient to show 
that the process of manufacture employed in this bloomery 
was, most likely, that known as the direct or Catalan process, 
one still adopted on the continent to a small extent, and by 
which method, the ore, either in its raw condition, or pre- 
viously subjected to a preliminary roasting, is reduced to the 
metallic form by the direct action of the fuel and without the 
intervention of any flux, such as limestone. 
