NOTES AND CORRESPONDENCE.
Discussion on Spontaneous Generation at the French Academy.—
We take for granted that our readers are aware of the present
state of the controversy in France relative to the question of
spontaneous generation. M. Pouchet, in his important work
' He'te'rogenie/ had replied to all the objections which the
antagonists of spontaneous generation had previously made,
including those which were founded on the valuable researches
of Schultze. Professor "Wyman, of Boston (U.S.), arrived
independently at the same conclusions as M. Pouchet, the
general result of his experiments being that the boiled
infusions of organic matter made use of, exposed only to air
which had passed through tubes heated to redness, or enclosed
with air in hermetically sealed vessels, and exposed to boiling
water, became the seat of infusorial life. M. Pasteur has
long been the leading opponent of this theory; and whilst a
series of experiments which he submitted to the Paris
Academy of Sciences some time ago met many of the
arguments which Pouchet had brought forward, he furthermore
stated that it was always possible to obtain, in a given
locality, an appi'eciable but limited amount of atmospheric air
not having undergone any sort of physical or chemical
modification, and nevertheless entirely unfit to produce any
alteration whatever in a liquid especially putrescible. MM.
Pouchet, Joly, and Musset, in their desire to meet this objection, ascended the glaciers of La Maladetta, near Rencluse, in
the Pyrenees, taking with them a certain number of flasks
each filled one third with an infusion of hay filtered and
boiled for more than an hour. No air was contained in the
flasks, and care was taken that they were hermetically closed.
Four of them were filled with air on the surface of the
glacier and four in a crevasse. The examination of four of
the flasks three days afterwards disclosed many specimens of
Bacteria, Manas, Vibrio, Mucedinea, and Amoeba. They
state, however, in a note, that all the other retorts presented
identical results. From this the three experimentalists
144
MEMORANDA.
conclude that the air of Maladetta, and, in general, the air of
high mountains, does not fulfil the conditions which M.
Pasteur predicted of it. At a recent meeting of the Paris
Academy M. Pasteur, [in vindication of his original theory,
made the following remarks:—" The attentive reader will
see that I do'jldf n3ak§use iiithis discussion 6f the; advantage
which my opponents give me by not speaking of Mucedin<e
and Infusoria in more than four of their eight flasks, a
circumstance Avhich proves that the results which are stated
to be contradictory to my own in reality confirm them; and
this remark would lead one to suppose that the four flasks
alluded to contained neither Mucedinece nor Infusoria.
At the meeting of the Academy on the 16th ult., a note
was read from M. Joly, stating that these four flasks did
contain organic matter, and that, if no mention of the circumstances was made in the note presented to the Academy, it
was simply a mistake of M. Musset, who prepared the paper.
" M. Pasteur," continues M. Joly, " is entirely mistaken; he
has judged us without hearing us; after having asked for
information respecting the four flasks, he did not allow himself time to receive an answer; if he had waitedjone day more,
he would have been spared the contradiction we are forced
to give him.5'
In announcing that M. Joly's letter would be inserted in
the Comptes-Rendus, M. Flourens said—" Several newspapers
have reproached me with not giving my opinion on spontaneous generation. As long as I had not formed an opinion I
had nothing to say. My opinion is, however, now formed, and
I will give it. M. Pasteur's experiments are decisive. What
is necessary for the production of animalcules if spontaneous
generation be a fact ? Air and liquid susceptible of putrescence. But M. Pasteur puts air and liquids susceptible
of putrescence together, and nothing happens. There is no
such thing as spontaneous generation. To doubt any longer
is to misunderstand the question."
M. de Quatrefages believed that, if the Academy were
going to institute further experiments, it would be necessary
that they should be carried on, not only in suitable localities,
but in several places successively; for it followed from experiments formerly undertaken by himself that germs or
sporules are so abundant in the atmosphere that it might very
well happen that a hundred or more vessels open in the same
place might all become the seat of microscopic products.
M. Henri Sainte-Claire Deville, who has repeated M.
Pasteur's experiments before a numerous audience at his lectures on chemistry at the Sorbonne, and has always found
MEMORANDA.
145
them perfectly exact, insisted on the necessity of following
with absolute accuracy the directions given by M. Pasteur,
directions which cannot be deviated from with impunity.
' M. Regnault entirely supported M. H. Sainte-Claire Deville's remark; he had seen in his countless experiments on
the expansion of gas how, even in working with the mercury
trough, it was difficult entirely to prevent the introduction of
extraneous air; the laisser alter with which M. Pouchet had
carried out his first experiments had greatly astonished him,
M. Pasteur reminded the Academy that he had formerly
stated that the mercury trough was a receptacle of a multitude
of germs which it caused to enter into all the bottles and
tubes manipnlated in it.
M. Milne-Edwards begged that an important experiment
which he had previously referred to might not be forgotten.
A small capsule containing germs derived from the atmosphere
was floated on the surface of a liquid peculiarly susceptible of
putrescence, and the liquid, even after many days, remained
completely limpid and unaltered; afterwards, on overturning
the capsule, the liquid became impregnated in some way or
other, and at the end of a few days it was seen to be filled
with a multitude of organized products.
'
..
M. Pasteur and other members' took this opportunity of
calling attention to the simpler and more decisive experiment
—a. real experimentum crucis—which consists in putting
side by side two flask with necks drawn out to a point, and
containing the same fermentable liquid, the open and slender
neck of the one flasks remaining straight and vertical, whilst
the slender and open neck of the other flask remained bent,
with the opening downwards. The liquid of the first vessel
was soon invaded by microscopic vegetation, although often,
at least, the liquid of the second vessel remained entirely
unaltered.
M. Pasteur had attended the meeting of the Academy for
the purpose of exhibiting two flasks which he had filled with
air on the Mer de Glace, without the contents having been in
any way affected. After the meeting he met his colleague,
M. Fremy, in the library, and the latter asked him what
would happen if the neck of the vessel were broken. M.
Pasteur did not hesitate to reply, that Mucedinem would soon
make their appearance. The neck of one of the flasks was
accordingly broken, and the flask itself placed in a corner of
the library. When M. Fre"my and M. Pasteur returned
eight hours later, the liquid, previously so clear, had lost its
transparency, numerous living organisms were visible, and
there was already a thin deposit of dead ones—thus brilliantly
confirming the results of M. Pasteur's experiments.
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-MEMOKANDA.
We conclude our notice with an account of some experiments made by M. Pouchet with air collected on Mont Blanc
by Dr. Kolb. Two vessels containing air, obtained at a
height of 4810 metres, were opened under the surface of a
decoction of common clover, which had been boiled for an
hour, and was still at almost the boiling-point. The rising
of the liquid in the vessels showed that they had been
hermetically closed, the air whicli they contained having
preserved all its rarefaction. After having recorked the
flasks in the hot liquid, the necks were put into mercury
heated for an hour to 160°. The third day the decoction,
which occupied about a third of the vessels, became clouded,,
and it was evident that Infusoria had been produced. Viewed
under the microscope, the decoction was found to be filled
with living monads of a size intermediate between Monas lens
and Monas corpusculum, with Spirillum, and with Bacterium.
Some Amcebce immobiles were also observed. A flask of air
obtained on the summit of the Buet, at a height of 3166
metres, and partly filled with the same liquid, gave absolutely analogous results. In some centimetres of air
obtained on Monte Hosa, monads and vibrios have also been
produced. These experiments on the air of Mont Blanc, and
some other of the higher peaks of the Alps, go to prove, as
remarked by M. Pouchet, contrary to the assertion of M.
Pasteur, tliat whatever be the place or height whence it is
obtained, it is uniformly capable of producing living animalcules. M. Pouchet remarks that, at all these considerable
latitudes, the air is almost entirely deprived of organic
corpuscles. The examination both of air and snow proves it.
Neither ova nor spores can be discovered. Thus it would
seem that the question concerning the high air is at.present
undecided. We need, however, scarcely remark that the
experimentum crucis alluded to by M. Pasteur is the real
point of the controversy, and one, moreover, which renders
journeys to distant mountain ranges unnecessary. Can M.
Pouchet reply to it ? It is simple— it requires no elaboration;
the comparative skill of the experimenter, therefore, need no
longer be any element in the inquiry. It is here that
M. Pouchet must silence M. Pasteur, or in his turn hold his
peace.—Reader, Dec. 12.
Anatomy of Helix aspersa.—In your numbers for January,
1863, and October, 1861, I observed two excellent papers by
Dr. Lawson on the anatomy of Limax maximus and Heii.v
aspersa.
MEMORANDA.
147
Permit me to make a few observations on his interpretations
of the generative organs of those animals. Having had occasion to dissect a specimen of Helix aspersa, I was struck with
the immense number of zoosperms to be found in the gland
which Dr. Lawson calls the ovary, and on further investigations on other specimens, as well as on Arion empiricorum
and on specimens of the genera Limnjeus and Planorbis, I
find I can quite bear out the anatomy as given by Gegenbaur, as I have before me preparations of cseca of this gland,
which show the zoosperms in situ in the centre, with ova in
all stages of development towards the periphery, but I cannot make out any double membrane as described by Meckel
and Siebold.
The presence of zoosperms in this gland is, I think, conclusive as to its being a testicle as well as ovary, for they are
too numerous to have come in accidentally, and their presence
in caeca in which all the ova are too young to be impregnated
show that they are not derived from some exterior source for
that purpose, which is also very improbable on other grounds;
the duct is also stuffed full of zoosperms, and it seems strange
that Carus should have taken them for ciliae.
Dr. Lawson thinks that the prostate is the testis; but the
fact that in the Planorbis the male duct separates from the
uterus and, receiving the secretion of the prostate in its
course, goes on to join the sac of the male opening, shows
that the prostate is simply an accessory organ.
I shall be happy to show Dr. Lawson the preparations
above referred to, and apologising for occupying your, valuable
space.—ALFRED SANDERS, M.R.C.S., F.L.S., 22, Beaufort
Villas, Brixton.
VOL. IV.—NEW SER.