1804. ] Sketch of the Life and Charafter of the late Dr. Prieftley, 359. 
pare the way for the reception of the 
Hartleian theory of the human mind, 
which he was then engaged in prefenting 
under a more popular and intelligible form. 
‘They who conceive Dr. Prieftley to have 
been triumphant in argument on this oc- 
cafion, agree in difapproving (as he him- 
felf did afterwards) the contempt and far- 
caf with which he treated his antago- 
nifts, which they do not think excufed by 
the air ef arrogance and fzlf-{ufiiciency 
affumed by thefe writers in their ftric- 
tures upon otherreafoners. But this was 
not the only inftance in which he thought 
it allowable to enliven the drynefs of con. 
troverfy by ftrokes of ridicule. He never 
intentionally mifreprefented either the ar- 
guments or the purpofes of an opponent ; 
but he meafured the refpeét with which he 
treated him, by that which he felt for him 
in his own mind, : 
In his publication of Hartley’s Theory 
he had exprefled fome doubts. as te the 
common hypothefis, that man pofleffes a 
foul, or immaterial! fubftance, totally dif- 
tinct from his body. For th’s opinion he 
had undergone obloquy as a favourer of 
Atheifm; but, as no perfonal imputa- 
tion was of weight with him in the pur- 
fuit of what he thought to be the truth, 
~hedid not fcruple, in 1777, to publith 
¢ Difguifitions relatmg to Matter and 
Spirit ;°’ in which he gave a hittory of the 
philofophical do&rine concerning the foul, 
and openly fupported the material fyftem, 
which makes it homogeneous with the bo- 
dy. Perhaps, of all Dr. Prieftley’s devia- 
tions fromreceived opinicns, this has fub- 
jc&ted him to the greateft odium, and. has 
moft flartled the true friends of reafon and 
free enquiry, on account of its fuppofed 
confequences. The natural proofs of a 
future {tate appear to be fo much invali- 
dated by the rejection of a feparate prin- 
ciple, the feat of thought, which may 
elcape from the perifhing body to which 
it is temporarily united, that he feemed to 
have been employed in demolifhing ove of 
the great pillars upon which religion is 
founded. It is enough here to obferve, 
that, in Dr. Prieftley’s mind, the defi- 
ciency of thefe natural proofs only ope- 
rated as an additional argument in favour 
of revelation; the neceflity of which, to 
fupport the mof important point of human 
belief, was thereby rendered more ftiik- 
ingly apparent. It may be added, that 
as he materialized fpirit, fo he, in fome 
meafure, fpiritualized matter, by affign- 
ing to it penetrability and other fubtle 
qualities. 
At this time he alfo appeared in great 
force as the champion of the dogtrine of 
philofophical neceffity ; a doStrine not lets 
obnoxious to many, on account of its fup.. 
pofed effets on morality, than the former.e:« 
To him, however, it was the fource (as 
he always afleried) of the higheft fatisfac. 
tion, both religious asid moral; and a 
number of his followers have found it, 
in like manner, compatible with all the 
beft principles of human condu&. With 
his intimate friend, Dr. Price, whofe opi- 
nions in both the laft-mentioned points was 
radicaliy different from his, a correfponds 
ence relative to them took place, which 
was publifhed in a volume, and affords a 
moit pleafing example of debate, carried 
on with perfeét urbanity, and every token 
of mutual refpeét and affection. 
Such was the wonderful compafs.and 
verfatility of his mind, that at this very 
period he was carrying on that courte 
of difcovery concerniag atriform bodies, 
which has rendered his name fo illuftrious 
among philofophical chemifis. In the Phi- 
lofophical Tranfaétions for 1773, we find 
a paper containing ‘* Ob{crvations on dif=_ 
ferent Kinds of Air,” by Dr, Prieftley 5 
which obtained the honorary prize of 
Copley’s medal. Thefe were reprinteds 
with many important additions, in the 
firft volume of his ** Experiments and Gbe. 
fervations on different Kinds of Air,” 8vo. 
1774. A fecond volume of this work 
was publifhed in 1775, and a third in 
'777- Yo give the fligntelt view of the 
or ginal matter in thefe volumes, would oc« 
cupy more time and fpace than this fketcly - 
permits; but it may with juftice be af- 
firmed, that they added a greater mals of 
fact to the hiftory of aériform fluids than 
the united labours of ail others employed 
upon the fame fubject. Some of the naoft 
firiking of his difcoveries were thofe of 
nitrous, and dephlogifticated, er pure, air; 
of the reftoration of vitiated air by vege- 
tation ; of the influence of light on vegeta- 
bles, and of the effects of refpiration upon 
the biood. In thefe volumes he did not 
attempt theory or fyfiematic arrangement, 
thinking that the knowledge of faéts was 
not fuihciently advanced for that purpofe ; 
and he threw them out hailily as new mat. 
ter occurred, in purfuance of his liberal 
principle already noticed, that fellow-ja- 
bourers in matters of fcience fhould as 
foon as poffitle be apprized ef dilceveries 
which might put them in the track. of 
making others. 
The name of Prieftley was by thefe 
publications fpread throvgh all the en- 
lightened countries of Europe, and ,ho- 
nours from fcientific bodies in various 
“parts 
