368 
NATURE 

separated bya valley from my house. Every flash I observed 
was double, composed I imagine of an ascending and de- 
scendinz current. In every instance one of the two flashes 
was brighter then the other; but I could detect no difference 
of time; as fir as the eye could judge they were simu!- 
taneous. The inference I am disposed to draw from these facts 
is this, that during thunderstorms ascending currents are to be 
guarded against no Jess than descending ones; that when chim- 
ney-pieces are shivered and people sitting by the fire side are killed, 
the electric fluid has not come down the chimney at all, but has | 
proceeded from the earth, and, having found a good conductor 
in the fender and grate, has passed through them harml-ssly, and 
has then overflowed, so to say, into the room, or shattered the 
non-conducting masonry. Continuous lightning-conductors, on Sir 
Snow Harvis’s principle, afford sufficient protection to public 
buildings, but metal pinnacles terminating below in masonry or 
woodwork are likely to cause mischief, and iron pillars, unless 
insula‘ed below by some non-conducting substance, must be equally 
objectionable. C. A. JoHNs 


SIR WILLIAM THOMSON ON THE LAW OF 
BIOGENESIS AND THE LAW OF GRAVI- 
TATION 
PASSAGE in the address of the President of the 
British Association appears to me so remarkable, 
and so much at variance with the notions entertained by 
biologists of various shades of opinion, that I am sur- | 
prised that no observations were made upon it during the 
sectional meetings, and bez now to draw attention to it. 
I may mention that in the discussion on spontaneous 
did say substantially what I now write to you, but no one 
present defended Sir William Thomson’s position. The 
passage in question is as follows : “ But science brings a 
vast mass of inductive evidence against this hypothesis of 
spontaneous generation, as you have heard from my pre- 
decessor in the Presidential chair. Careful enough 
scrutiny has, in every case up to the present day, dis- 
covered life as antecedent to life. Dead matter cannot 
become living without coming under the influence of 
matter previously alive. This seems to me as sure a 
teaching of science as the law of gravitation. . . . I 
coness to being deeply impressed by the evidence put 
before us by Prof. Huxley, and I am ready to adopt asan 
article of scientific faith, true through all space and 
through all time, that Jife proceeds from life, and from 
nothing but life.” * In the first place it is to be remarked 
upon this passage, that the reference to his ‘ predecessor in 
the Presidential chair,’ and to ‘ the evidence put before 
us by Prof. Huxley,” is made in such a way as would lead 
an uninformed person to suppose that not only was the 
speaker simply availing himself of that evidence, but also 
merely following or re-enunciating a belief previously ex- 
pressed by Prof. Huxley. This I do not for a moment 
suppose was in any way the meaning of Sir W. Thom- 
son, who unintentionally has made it appear that Prof. 
_ Huxley comes to the same conclusion from the considera- 
tion of certain facts, as he does. 
suring concord having an existence, I doubt if any single 
biologist of name (of whatever philosophic tendencies) 
would venture to assert that it is as sure a teaching of 
science as the law of gravitation that dead matter cannot | 
become living without coming under the influence of 
matter previously alive, and conclusions derived from a 
consideration of a vast series of facts prohibit an 
evolutionist from accepting such a doctrine with- 
out the most complete and _ widely-reaching evi- 
dence in its favour. Sir William Thomson’s autho- 
rity must be accepted as unquestionable as to the 
amount of sureness which may be attributed to the law of 
gravi ation ; but with great deference to him, I should 
like to ask if he would definitely maintain that it is no 
* Nature, Vol, iv., [e 260. 

| of isolation she refuses to Go so. 
greater than that which may be attributed to the dogma 
“no life except from life.” It is the fact that within 
human observation the law of gravitation is a true state- 
ment; it is also the fact that within human observation 
the dogma “no life except from life” is a true statement ; 
but how can it be for a moment supposed that this places 
the two statements in the same position of sureness? 
Does not all depend on that term “ within human obser- 
vation?” Will not the sureness depend on the extent and 
thoroughness of the observation? And is it not the case 
that whilst human observation of bodies in relation to the 
law of gravitation is of the most vast character—embracing 
not on'y all varieties of terrestrial matter, but innumerable 
extra-terrestrial bodies—the human observation of the way 
in which living matter originates or grows, is a mere trifle 
so insiznificant in extent that it is as a dropin the ocean? 
Sir William Thomson speaks of being “ deeply impressed 
by the evidence put before us by Prof. Huxley,” and is 
thereupon ready to adopt an article of scientific faith 
“true through all space and time.” What was the evidence 
in question? The merest fragment, as Prof. Huxley would 
himself acknowledge (though associated with much moré 
evidence upon allied matters)—simply this by no means 
astonishing though much controverted fact, that when out oi 
the unspeakably many kinds of mineral matter which you 
mighttake, you take one or twoand boil them and seal them 
up and submit them to a variety of processes, the object of 
which is not to produce favourable conditions for the evo- 
lution of life, but to prevent the access of already living 
matter—you don’t get life produced. The whole of this 
Rete canits Section D onthe last day of themecting Um| kind of experiment, and of the evidence which so much 
3) 
impressed Sir William Thomson, cannot—attended as it 
is with negative results—have anything to do with the 
general question of the de zovo originof living matter. Such 
evidence merely relates to a particularsupposed case of such 
origin, one out of thousands conceivab'e. Yet this is what 
it seems to me—I write with diffidence—Sir William 
Thomson has taken as evidence of the same value as that 
on which rests the law of gravitation. Because it seems 
rather more probable than not that organisms do not 
arise de zovo in boiled and sealed solutions of tartrate of 
ammonia, in hay-decoctions and turnip-juice, /i-7e/ore it 
is true through all space and all time that dead matter 
never becomes living without the action of living matter ; 
therefore nowhere to-day on the whole earth—in the sea 
charged with gases, open to sunlight and atmosphere, 
holding salts and complex semi-organic compounds, 
suspended and in solution—is this process gong on; 
in no pond ; under nomoss ; and not only to-day, but we 
are to conclude that never at any time did Nature in her 
great laboratory produce life from mineral matter, because 
in certain arbitrary, crude, and utterly artificial conditions 
Is it true that the law of 
gravitation is no surer a teaching of science than the 
dogma about the origin of life which rests on such logic ? 
That I have not misrepresented the utter poverty of 
| observation upon the origin of life will, I believe, 
So far from this re-as- | 

be admitted by all naturalists— possibly individuals 
unacquainted with biclogical phenomena may have 
conceived it to have been relatively more extensive. 
We have been able to trace the commencement of so 
many of the various living forms to egzs, that it becomes 
waste of time to examine into cases of alleged spontaneous 
origin of comp/ex forms from mineral matter ; and biologists 
have nowtolook forthe formation of simple organic material. 
Observations therefore which merely tend to disprove the 
spontaneous productions of maggots, worms, ciliated 
infusoria, and fungi, are not to be reckoned as “ evidence 
on the origin ot life,” they do not bear on the question as 
ic now presents itself, the working hypothesis of science 
being, not that avzmals or plants originate de nove, but 
that 07, ganic matter has at one time done so, and is doing 
so stil. Itis, 1 believe, just to assert that observation 
bearing on this hypothesis is almost eatirely wanting, and 

