, 1870-05-08
PROFESSOR TYNDALL ON FL
TERED AIR.

HRUEEESQH 1NOA1A Vct GA-
TERED AIR
10 n< EeitcT ef the London 7iase1.
s1a. The theory of disease was never dis
cuseed with more ea1nestness, or with greater
precision, than It the present Tine The e1-
act methods pursued in physics and chemistry,
both As regards reasoning and experiment. ARE
mailing their influence felt in medicine and
surgery: and they promise, While assigning bot
narrow Units To onE present secu1ate h,owl~
etEe, to inaure its healthy growth It Is;
think. Of capital importance 70 mark each suo-
cessive step by which that hoHledge is surely
and certainly augmented: to detach from the
domain OF ragueness and uncertainty each suc-
eesaiYe fragment Of demonstrated truth. Nov,
il the published data be correct, it seenas to ma
that such step has been recently taken with
reference to the gern-theory OF the puhefsc-
ton Of wounds, sud thst the evidence IN favor
Of that theory amounts to physical 9t1emon-
strat1op OF its truth This result snd its basis-
propose here TO describe sud define.
The entrance Of air into the wound il the
dresl Of the SURGEON. When &n abscses i8
opened he must prevent the air from ming
ling with the b1ood-clots II he would avoid pu-
trefsction and its teeming accompaniment or
anima1cu1e life. Some eminent London sur
geons inform me that they never squeeze an
abscess, lest when the pressure il relaxed the
sir should be sucked in. Now, whence this
dreaded powez2 Is it the air itself that cau5es
putrefaction, OF is it something cau1ed me-
ch1nicalIf by the air7 4 follower Of GAY
Lussac would affirm the former: heterose-
mist would refer the aninalcules to "spontane-
Gus generations" holder OF the Eetue-theory
would aaCribe the put1efachon to seeds OF
eggs aostiDg in the atmosphere, and which,
when sown upon the wound. spront into this
crop Of minute organisms Do any ddtd exist
which will enable us to say, with certainty,
which party is right? think 60.
It would DO very difficult TO reduce the pu-
trefyibg power OF pure hir, even ii it existed,
to absolute demonstration for. however
cleansed in appearance, . stubborn obiectof
might still urge that the sir was not clesnsed
IN reality; that germs azist, though they battle
our attempts to reveal them. But this Diff
Guilty does not hamper the other side; for il,
notwithstanding the risk Of these residusl
tent to produce the phenomena OF Pntrefac-
/ ton, there ia no escape from the inference
! that, as regards the point to be decided, such
air is perfectly filtered; and ita proved isnpo-
! tence would be demonstration OF the tznth
Of the getm-theory. By "visihly pure air" I
and Intensely concentrated beam OF Light, in =
spaca not othersiss illuminated, Eeyesla 20
| tface OF floating matter to the eye.
| :. How, thau, ato ne 30 obta1o our hltafed. II
and, having obtained it, how are We to apply it
! to . wound and mix it aNectua{1E NTH the
and an inference, which, taken together reflect
| the highest credit On bis sagacity, wera made
| and drawn by Professor Joseph Lister, Of Ed
! inhu1gh. He found, aud balieEa it is the
! universal experience Of surgervto ~fnd, that
when the lung is wounded by the spike OF =
ruing3e freely With the blood, but that pufe-
faction never ensuea. Here Is the statement
of Professor Lister, abhsaziated. but in his
OWL words:
"1 have explained tony own mind the re-
nnarkable TACT that in simple fractures Of the
! the blood enuaad into the pleural cavity,
though freely ulted with air, undergoes no
decomposition The air ia sometimes pumped
into the plepzalazyits in such ahssnd7nse shat,
| making its way through the round, it !naates
the cellular tsssuaof the whole boF. Yet this
to the surgeon. Why A& introdncea into the
p1eu1l cavity through wounded lung should
haze such who'll difersnt effect from that
ents1'aR t~tough . permanently open wound
! n*-ctrating from without. Waa TO me- COLI
plete mystery till heard Of the germ theory
Of putrefaction, when it st once occurred to
me that it WIS only natu1l that the air ahould
be filtered Of germs by Abe al1 passages, pnH
Of whose Offices is to arrest inhaled particles
Of dust, and prevent them from entering tho
air-ceIs, In truth, this facs in practical sur
gerry, when duly considered, affords IS good
evidence IN support Of the germ OF putrefac-
tion 9 as sny IS experiment that can be performed
Here is surmise which bears upon II tha
mark OF genius, but which, nevertheless, needs
yeri6cation- II in the place Of tha words ait
| is only natural" we were authorized to write
sit is perfectly cersain," the demonstration
would be complete. Now, this is exactly what
experiments with beam of Light enable ns to
do. One evening towards the close OF Last
year, while pouring various gases ACROSS the
dust track OF beam in the laboratory Of the
Royal Institution, the Thought occurred to ne
of dsplactng by my breath the Illuminated
dust. then noticed, for the first tune, the
expired towards the eud Of an expiration By
an Intentional effort Of expulsion the lungs
may be far more efectually emptied Of air
than BY ordinary respiration and. by such an
efo1t, which discharges the air from the into
nor portion Of the lungs into tho bonn, the
There is no speck Or mote Of my kind in such
air. II is true elastic fluid, without traca
OF cloud or floatiDg matter.
Thus, by ocular evidence We prove the filter
ing power Of the lungs, and by the experience
ot sgIgery We prove the insseppeten1Se ct al
removed By the process of filtration arc there
fore the cause Of the putrefaction, and ita IS
sociated phenomens Of animalcule life, which
VAS 10 be demonstrated,
AZ guide to the practical surgeon, tho es-
Enlistment Of this TACT is plainly Of the verJ
highest importance. Professor Lister nov
avails himself Of the f1tering power OF cottor
moo1 in treating numerous class Of wounds
He first destroys tie germs adherent to ths
I wool, and by a proper lotion he Kills those
| which mar be scattered On the flesh. The
cleaned wool placed upon tha wound permit:
Of a free diffusion Of tho air, but entirely IN;
tcrcepts the germs, and thua keeps the blooi
perfectly aweet. It Is essential that no nastte'
; from the wound should reach the out
side air, for ouch matter would open high
way for the aniralcules. I may add thai whet
the foregoing observations on the 61terint
power Of the 1ungs were made, had n
( thought, md but little knowledge, Of the germ
theory. Their vnlue az evidence is enhanced
by the consideration that they are abso1ute1
independent OF al theoretic basisf. an, sit
your obedient servant, JouN TyyDAIl..
RorAn INSTITUTIONS, April 6.