84 REPORT—1848. 
way, so as to reduce the expenditure of fuel to that which takes place in the 
blast-furnace. Proceeding cautiously and in a commercial spirit, 1 do not 
despair of so combining profit with experiment, as in practice to show the ex- 
ample of the final ceconomy I have pointed out, namely, that for less than 
2 tons of coal put into the furnace, I shall complete the manufacture from the 
ores to malleable iron, thus ceconomizing two-thirds of the coal used in the 
iron manufacture in this country. 
If the result I have pointed to is ever arrived at, as | believe it may be, that 
the whole process from the ore to the malleable iron bé completed and 
achieved by the coal put into the furnace, for the purpose only, according to 
present practice, of reducing the iron from its ores, the saving of fuel in the 
manufacture of iron in Great Britain will not be less than 5,000,000 tons a 
year, worth considerably more than £1,000,000 sterling. Thus the blast- 
furnace would come to be considered, not merely as a smelting-furnace for the 
reduction of ores and metals, but as a gas generator, the source whence was 
to be drawn all the heat necessary for all the subsequent processes. I will not 
indulge myself further in speculating on the great revolution so vast an ceco- 
nomy would produce, but will content myself with the hope that my observa- 
tions will be received with indulgence, as I wish to divest them of all preten- 
sions. My practice makes the first part of my subject sure ; and in speculating 
on the further use of the gases passing off from our blast-furnaces as a substitute 
for coal in the subsequent processes of converting pig into malleable iron, I 
have followed the lead.and indication which the facts I have arrived at obvi- 
ously offer. I hope my notice of the subject will attract the attention of those 
in the iron trade more competent than I am to pursue it to a satisfactory result ; 
and I am content to place my views on record as those of one who is convinced 
that the prosperity of the iron trade depends on the ceconomy of its processes, 
and that in fact its profits must be made out of its savings. 
Report of progress in the investigation of the Action of Carbonic Acid 
on the Growth of Plants ailied to those of the Coal Formations. By 
Rospert Hunt. 
Tuts investigation was assigned to the charge of a committee, and two sets 
of experiments have been established, one by Dr. Daubeny at Oxford, and 
the other by Mr. Hunt in London, upon ferns which have been supplied from 
the Royal Botanic Gardens at Kew. The arrangements are such, that two 
sets of these plants, belonging to the same class, are made to grow under the 
same circumstances, except that one set is supplied with measured quantities 
of carbonic acid. Numerous preliminary experiments had to be made, and 
several sets of plants have been destroyed in the progress of these. No 
general result can be announced beyond the fact, that the plants, by being 
gradually inured to the agency of the carbonic acid, can be made to bear a 
greater quantity than when a large per-centage is given to them at once. 
The experiments must be continued over a long period before we can arrive 
at any decided result. 
Supplement to the Temperature Tables printed in the Report of the 
British Association for 1847. By Professor H. W. Dove, Cor. 
Memb. of the British Association ; containing 84 additional Stations. 
. 
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