F 
it.i Relations xoith Agriculture. 825 
acid that the pig-iron they produce is entirely untitted for the ordi- 
nary Bessemer process. But, it is when we are dealing with iron- 
ore in tlie still more recently deposited rocks of the Lias formation, 
that we meet with the full measui-e of inconvenience caused by the 
presence of phosphorus. The iron-mud and earthy mud, the result of 
the disintegration of the shales of the period, would be carried down 
into the seas of that time. There, the accumulated remains of 
organised beings of marine origin, which had derived some phos- 
phorus from the sea they inhabited, were buried in the mud con- 
taining carbonate of iron, and so became part and parcel of the 
ironstone irow so extensively worked in the Cleveland Hills. 
Among the animals so entombed some were of considerable dimen- 
sions. 
In order to convey an idea of the volumetric extent to which the 
non-metals enter into Cleveland pig-iron, I constructed a diagram 
showmg the relations they bear to the metal itself. In it the pure 
metal iron is represented by an equal-sided rectangular figure con- 
taining 400 square inches, being thus a square of 20 inches to the 
side. With this as a standard of comparison, carbon is represented 
by a square containing 49.81 square inches ; phosphorus, 22‘09 ; 
silicon, 21 ’90 ; and sulphur, one containing 2‘37 square inches. Rich, 
comparatively speaking, as Cleveland ironstone is in phosphoric acid, 
it is obvious that, although a low-priced mineral, it would be im- 
practicable to use it as a fertiliser on our land. When, however, we 
submit it to the action of the blast-furnace, the phosphorus contained 
in 3| tons of ore passes into 20 cwt. of pig-iron. A good deal more 
than twenty years ago I pointed out the loss our country was incur- 
ring by allowing the phosphorus of 20,000 tons of phosphoric acid to 
poison 2,000,000 tons of pig-iron annually, at the same time that our 
ships were scouring tlie seas in search of the identical substance from 
the remotest parts of the earth. 
5\'e are, I am glad to say, on the way of eventually removing 
this scandal from the manufacturing escutcheon of the nation, by 
the introduction of the basic process. Attempts, soon after its dis- 
covery, were made in Germany to free the slag — into which the phos- 
phorus as phosphoric acid passes — from what was useless as a manure, 
but which slag contains ten times as much phosphoric acid as did the 
parent ironstone. It was, howevei', speedily discovered that in the 
laboratory of Nature this operation was performed by the plants 
requiring phosphoric acid, — not with the same speed as, but much 
more cheaply than, it could be done in the workshops of the chemist. 
Lowthian Bell. 
'i K i 
