Basic Cinder as Manure. 
131 
The amount made in the different countries for the years 
ending December 31, 1888, and December 31, 1889, respectively, 
was as follows : — 
1889 
1888 
Country 
Total 
Inprotirou 
under *17 per 
cent, carbon 
Total 
Ingot-iron 
under -17 per 
cent, carbon 
England 
Germany and Austria . . . 
France 
Belgium and other countries. 
Tons 
493,919 
1,4.81,642 
222,392 
7<3,5!»9 
Tons 
348,828 
1,185,323 
159,271 
71,217 
Tons 
408,594 
1,27C,070 
222,333 
4G,237 
Tons 
276,470 
1,026,033 
158,223 
32,300 
Total . . . 
2,274,552 
1,764,039 
1,953,234 
1,493,032 
With this 2\ million tons of basic steel, about 700,000 tons 
of basic slag, containing phosphoric acid equal to about 36 per 
cent, of phosphate of lime (bone-earth), were produced. 
With the formation of this phosphoric slag, or basic cinder, 
arose the question, Can it be used as a manure to supply farm- 
crops with phosphoric acid ? The first, somewhat rough, experi- 
ments made with the slag itself in the neighbourhood of works 
producing it, and some made at Cirencester by the author, gave 
varying, and, on the whole, rather unsatisfactory, results, due, as 
we now know, to the slag not being sufficiently finely powdered. 
Scores of patents were taken out for processes by which the 
phosphoric acid might be utilised, mainly for agricultural pro- 
cesses. One of these was worked to a rather large extent. By 
it a fine, precipitated phosphate of lime, mainly dibasic phos- 
phate, is produced, containing 32 to 33 per cent, of phosphoric 
acid, equivalent to 70-73 per cent, of ordinary phosphate of 
lime. This is an excellent manure, but its high price prohibits 
its extensive use. 
There is now abundant evidence to show that the raw 
cinder, if very finely ground, is a very efficient phosphatic 
manure. That the ferrous oxide present is not in a form in which 
it is injurious to plants, is shown by the fact that dressings of 
one, two, and even three tons per acre may be given without 
injurious effects, though, it is true, with no more beneficial 
effects than very much smaller dressings. Chemical investiga- 
tion has shown that the phosphoric acid is combined with lime, 
chiefly in the form of tetrabasic phosphate (4CaO, P 2 0., or 
Ca 4 P 2 0 9 ), not in the more commonly occurring form of tribasic 
phosphate (Ca 3 P 2 O a ). 
The phosphate in this form is much more soluble in water 
k 2 
