[ 53 ^ ] 
been for your partial regard to it. I fliould be ferry 
to lee any part of it publifhed in the TranfaEiions , 
efpecially as I long ago laid afide the defign, which 
from the anfwer 1 received to the letter, of which I 
fen: you a copy, I did not then think myfelf at li- 
berty to profecute, and do not think, that I fhall 
again find leifure to refume it. I have long been of 
opinion, that, in order to attain a perfect knowledge 
of the nature of the air, we muff trace it from its 
hidden fources in the bowels of the earth ; and mult 
own myfelf ambitious of treading in your iheps, and 
of profecuting your enquiries concerning the nature 
of its vivifying fpirit j 
Non it a certandi cupidus , qitam propter amorem , 
Quod te imitari avco . 
With this view, 1 had collected, under proper 
heads, all that I found in authors relating to that 
fubjecl; and had prepared an apparatus, and alfo 
made fome experiments to difeover what alterations 
were produced in various kinds of air by fiagnation ; 
and what erfedts the different kinds of air, as well fim- 
ple as compounded, had,on animals included in them ■ 
and by thefe and fuch-like experiments, I might per- 
haps entertain too fanguine hopes of making fome 
ufeful difeoveries concerning the nature, and even 
the component ingredients, of the vivifying aerial 
fpirit. 
An ingenious friend,, on reading the account of 
your method of diftillation, was pleafed to fugged:, 
that the quantity of fleam might perhaps be increafed 
by heating the air, that is forced through the water 
contained in the ftill. This might be done conve- 
niently enough, by pafiing an iron pipe, that goes 
from. 
