142 
whole train of facts, laid down in this and former papers, 
as to the effects of a superabundant quantity of oxygen, 
was overlooked. The event proved in the most com- 
plete manner, and on a great scale, the pernicious effects 
of moisture. The furnace gradually became cooled 
where the steam entered ; the heat, set free by the decom- 
position of the water and the disengagement of oxygen, 
increased to an alarming pitch a considerable way up the 
furnace ; the quality of the iron became brittle, and as 
white in the fracture as silver ; the introduction of the 
steam was still continued, the descending materials were 
instantly robbed of their heat to facilitate the decomposi- 
tion of the water, and by-and-by the furnace closed entire- 
ly over, and the experiment ceased. 
This experiment, performed in a furnace 18 feet high, 
is a complete proof that heat is disengaged from bodies 
while they pass from the fluid to the aeriform state. The 
first instant of the discharge of steam, a very conside- 
rable portion of heat would be withdrawn from the fusing 
materials and united to the water. This, in its turn, 
would be ignited to whiteness, and decomposed upon the 
metals and coaks, in a superior region of the furnace. 
The process continuing for several hours, the materials at 
the tuyere were at last so completely deprived of the calorie 
by the continual torrent of steam, that they lost fluidity, 
cooled rapidly, and at last became black. Had another 
aperture for steam and for air been opened above these, 
now entirely shut up by the consolidated materials, the 
same effects would have been produced ; the immense 
quantity of caloric, disengaged by the decomposition of 
die ignited water, would now approach nearear to the top 
of the furnace, another stratum of fusing materials would 
again become consolidated, till in the end the whole fur- 
nace would be set fast from top to bottom. From the 
introduction of steam into the blast furnace, either as 
