Sept. 29, 1870] 
NATURE 
431 
Our own mechanics’ institutes and kindred undertakings 
are just now commencing their autumnal session. We 
commend to them the consideration whether the principle 
of self-help cannot be more definitely recognised than has 
hitherto been the case. We hear with pleasure that the 
Working Men’s College in Great Ormond Street is pro- 
jecting an extension of its scientific programme in the 
approaching session. Let men and women be treated, 
not as artisans, mechanics, or gentlemen, but simply as 
men and women, standing toward the teacher only in the 
position of recipients of something which he feels the 
power and necessity of imparting ; let no thought of any 
other relationship enter into this connection ; and we pre- 
dict for this and other equally admirable institutions a 
far wider popularity aad usefulness than they have hitherto 
enjoyed, 
REPLY TO PROFESSOR HUXLEY’S INAUGURAL 
ADDRESS AT LIVERPOOL ON THE QUESTION 
OF THE ORIGIN OF LIFE 
IL. 
“HE main argument must now be resumed: this having 
been cnly temporarily laid aside in order to inquire how 
far Prof. Huxley’s ‘long chain of evidence” touched the real 
point at issue. 
Haying shown that, in reality, this has no immediate bearing 
upon the question in dispute, and having endeavoured to show 
to what extent the burden of proof rests with Prof. Huxley and 
others who affirm the universality of Redi’s doctrine, it has now 
to be shown what evidence can be brought forward which may 
influence our judgment in the selection of one or other of the two 
possible modes by which alone the minute motionless specks of 
Living matter appearing in certain solutions can be supposed to 
originate. We must inquire, as much as possible independently 
of theoretical considerations, towards which of the two modes of 
origin—the germ or the germless—the evidence should induce 
us to lean. 
It will be well, however, in the first place, to submit the fol- 
lowing considerations to those who wish to form an unbiassed 
opinion upon the subject. Supposing that the minutest visible 
specks of living matter have originated from the growth of pre- 
existing zuzésié/e germs, there isstill no reason whatever to induce 
us to believe that the invisible portions of Living matter would 
differ from visible portions in their power of resisting the destruc- 
tive influence of heat. Whether visible or invisible, we are sup- 
posed only to have to do with Living matter, and it cannot be 
supposed that the qualities of this matter would vary simply 
because it existed in a state so minute as to elude our ob- 
servation. What has been found to hold good, therefore, 
concerning the inability of visible Living matter to resist the 
destructive agency of heat may also be presumed to hold good 
for any invisible portions of Living matter. Invisible germs must 
be supposed to be amenable to the same influences as those 
’ which affect visible germs.* If the latter are destroyed by any 
given amount of heat, we should have every reason to expect that 
the former would also be destroyed under similar circumstances. + 
It seems to me that the ov/y means which we at present possess 
of throwing light upon this question, as to whether the minute 
Living things which appear under our eyes, in certain solutions, 
* It was suggested to me by a friend that extreme smallness of size 
might be a protection against the influence of heat ; in illustration of which 
possibility my attention was called to the fact that the water in capillary 
tubes will not freeze at times when that in larger vessels will become solidified. 
But although the water in the capillary tube does not freeze, this is due rather 
to some altered molecular condition of the fluid, and not because its tem- 
perature is not lowered just as much as that contained in the larger vessel 
which does freeze. 1 cannot see how smallness of size can confer immunity 
from alterations of temperature—more especially of any particles, however 
minute, which are contained within hermetically sealed flasks retained at a 
given heat for four hours. : : 
+ I have already pointed out (note p. 410) that the problem is utterly im- 
sible to be solved if this be not granted as a probability ; and that, simi- 
larly, without the concession that ivvésié/e crystalline matter resembled in 
its properties visidde crystalline matter, it would be equally impossible to con- 
sider it as Jroved that a crystal can originate in a solution de ovo, inde- 
pendently of a pre-existing line germ. 
really derive their origin from ‘pre-existing Living things, or 
spring into being de nove, is to subject other suitable solutions 
within hermetically sealed flasks, to a degree of heat which, on 
good evidence, is deemed adequate to kill all pre-existing Living 
things. If Living things are, notwithstanding the destructive ex- 
posure, subsequently to be found in the fluids when the flasks 
are opened, the evidence would seem to be strongly in favour of 
the dz nove origination of such Living things—more especially 
if the heat employed had been great and long-continued. So 
far as all direct experiment and observation has hitherto gone, 
no Living thing whatsoever has been found to survive in a fluid 
which has been exposed for two or three minutes toa temperature 
of 110°C. And if we couple this fact with a due consideration 
of the fundamental unity in Nature of all Living matter, the sup- 
position that any Living things—found in solutions that had been 
submitted to a far greater heat for two, three, or four hours—had 
braved this heat with impunity, would be an assumption seem- 
ingly much more improbable * than the only possible counter 
supposition, viz., thet the Living things had been evolved 
de novo. The former supposition would be less likely to be true, 
because, instead of being consistent or harmonising with our 
general knowledge, it would seem to be a mere isolated fact 
bearing on its face the impress of grave improbability. Ba- 
teria and fungus-spores which cannot, when made the subject 
of direct observation, resist the influence of a lower temperature, 
are, however, to be supposed capable of resisting the influence 
of a much higher temperature when-their behaviour is watched 
by no human eye, though at a juncture when human prejudice 
emphatically requires that they should do so.+ This extreme 
improbability—this isolated and otherwise unsupported notion 
—is cherished, whilst the other supposition, which is consistent 
with direct observation so far as it can go, and which is thorough'y 
in harmony with a great mass of scientific truth, is rejected. And 
why is it rejected? Because it is alleged that a great mass of 
human experience, having no immediate bearing upon this par- 
ticular subject, and which is only related thereto by analogy, 
seems to make it improbable. And yet, asa matter of fact,— 
and although precisely the same reasoning is applicable against 
the alternative which they adopt—if the probability of a present 
de novo origination of Living things, after the fashion which 
is alone maintained, were to be admitted by every scientific man 
to-morrow, the whole body of human experience would remain 
perfectly undisturbed. A new probability, akin to a fact,= and 
one of the most extreme importance, would, it is true, have been 
added to the sum-total of human knowledge, and the only loss 
or contradiction would be, that those who had hitherto cherished 
the formula omne vivunt ex vivo as the expression of a funda- 
mental truth, would have to give it up. Like many another 
dogma, which in the course of time is toppled over, this expres- 
sion of an over-hasty, though formerly justifiable, generalisation, 
now that it has been shown to be incompatible with the latest 
teachings of science, would haye to fall into the shade of cold 
neglect. 
* Although ‘‘germs,” so far as we know them, are incapable of resisting 
the influence of great and prolonged heat, it was suggested by Prof. Rolleston, 
in the discussion which took place in the Biological Section on Sept. 21, that 
some germs wight exist which were less amenable to the influence of heat, 
owing to the protein substances entering into their composition being in some 
peculiar isomeric state. We know for instance that peptone, which 1s a modi- 
fication of albumen, is not coagulable by heat. All that we should deduce 
from this fact, however, seems to be this, that whereas ordinary albumen 
can, under the influence of heat, be made to undergo a certain isomeric 
modification by which it is rendered ¢zsoduble ; this same albumen may, by a 
different process, be converted into feffone, a modification which is xot 
capable of being conyerted into the zzsodué/e isomeric condition by the 
application of heat. Too much stress must not be laid upon mere coagula- 
bility ; and we must be, as it seems to me, further careful not to mix up our 
conception of this property too closely with another which is quite distinct, 
viz., as to the ability of Living things to withstand the influence of heat. 
+ Here we are brought face to face with the real difficulty. In order to 
explain the results of certain experiments, we #zust accept an apparent in- 
fraction of one or other of two rules which have hitherto been found to be 
universal, so far as human experience has gone. A Living thing has no 
more been known to be capable of surviving a temperatue of 150° C., than 
another Living thing has been Aows to arise de novo. Prof. Huxley, and 
those who think with him, appear to forget, in their present extreme un- 
willingness to give up the doctrine one vivur ex vivo, that they can only 
retain it by abjuring another doctrine which has a similar seeming univer- 
sality, so far as human experience has gone. We have nothing, then, but 
probabilities to guide us in our choice. Hence much difference of opinion 
will probably exist, till scientific men in general haye come to adopt such 
physical doctrines concerning Life as those which Prof. Huxley has hitherto 
so ably taught. . 
t All so-called “facts” are, to the philosopher, only possibilities which 
vary in their degree of probability. This is inevitab!e, owing to the “‘ Rela- 
tivity of Knowledge,” so that possibilities, probabilities, and facts, merge 
insensibly into one another. 
