134 Remarks on Prtestley's Analysis 
it must have given a very perceivable addition of 
weight, he weighed the calx to which the iron had 
been reduced, and “I presently found,” says he, 
“ that the dephlogisticated air had actually been ims 
bibed by the iron. In the first instance, about 
twelve ounce-measures of dephlogisticated ait had 
disappeared, and the iron had gained six grains in 
weight. Repeating the experiment very frequently, 
I always found that other quantities of iron, treated 
in the same manner, gained similar additions of 
weight, which was always very nearly that of the 
air which disappeared. This calciform substance I 
found by various experiments, to be the same thing 
with the scales that fly from iron, whenit is made red- 
hot, or the substance into which it runs: in a very 
intense heat in an open fire.” And, in a note, he in- 
forms us, that this calx is the same with finery- 
cinder. 
_ Here then we have experiments of the same na- 
ture as those recited in the pamphlet under ex ami- 
nation, but simplified as they ought to be, and made 
with’ care and exactness, and in circumstances and 
by means, which leave littke or no room for error. 
But no azote made its appearance more than was 
contained in the air before the operation. The iron 
emitted nothing, but increased in weight as much, 
or nearly as much, as the oxygenous gas amounted 
to. About twelve ounce-measures of it disappéar- 
ed, and the iron increased in weight six grains; 
