21 
for the present, very briefly quote the conclusion or general 
result of such examination, viz., " That Mr. Dawson's hy- 
pothesis, in every point of view, is wholly inadmissible." 
As a further attempt to lay down a theory more consistent 
with obvious facts, we then drew up a statement of our views 
on that subject ; together with the sources of information on 
which they are grounded, which, with permission, we now beg 
to introduce, requesting as a favour, that any one who may 
have the misfortune to keep awake, during the very dry, 
tedious, and perhaps unintelligible detail, will kindly bear in 
mind that these views were advanced full 35 years ago. We 
are not aware, however, that much novelty has been discover- 
ed in this particular branch of research, and therefore pro- 
ceed therewith without further remark or apology.* 
" It is easier to find fault than to mend," says an old and true 
adage. To prove, however, that the preceding remarks origin- 
ated not merely from a spirit of contradiction, we will now 
submit to your disquisition, a few hypothetical observations, 
different indeed from those alluded to, but upon the same 
subject — the effect of air and moisture upon Blast Furnaces. 
And after the example of the author, whom as far as facts will 
bear us company, we shall always be proud to follow, we 
will first attempt an inquiry into the constitution of the atmos- 
phere ; at least, so far as respects the mixture and proportions 
of its constituent gases ; and the agency which aqueous 
vapour, or moisture possesses, in diminishing the fitness of 
the air for combustion, according as it abounds therein in 
weather of different temperatures. 
The atmosphere, we contend, is not a chemical, but a 
mechanical mixture of gases ; and Mr. Dalton's theory of 
the properties of that mixture, appears to us by uuch the 
most probable and satisfactory. 
* The Essay originally consisted of two parts — in the first Mr. Dawson's theory 
was examined and controverted — in the second, which is now published, an 
attempt is made to establish a more correct theory. 
