414 
pression that almost every one of those who had taken part in 
controversies which had been carried on both here and abroad 
concerning the Origin of Life, were prepared to admit, as Spal- 
lanzani had done, that the eggs or germs of such organisms as 
appear in infusions were unable to survive when the infusions 
containing them were raised to the temperature at which water 
boils. This impression was produced in part by the explicit 
statements onthe subject that had been made by very many 
biologists, and also in part by a comparatively recent and 
authoritative confirmation which this view as to the destructive 
effects of boiling infusions upon acteria had received. Little 
more than two years ago Prof. Huxley, as president of the 
British Association for the Advancement of Science, recorded 
experiments in his Inaugural Address which were obviously 
based upon this belief as a starting-point. And subsequently, 
in ove of the Sectional Meetings, after referring to some of my 
experiments, and to the fact that all unmistakeably vital move- 
ments ceased after Bacteria had been boiled, Prof. Huxley 
added : *—“ I cannot be certain about other persons, but I am 
of opinion that observers who have supposed they have found 
Bacteria surviving after boiling have made the mistake which 
I should have done at one time, and, in fact, have confused the 
Brownian movements with ¢rue /iving movements.” Prof. 
Huxley does not now (in reference to the experiments cited in 
my last communication) suggest that the organisms found in the 
infusions were dead and had been there before the fluids were 
boiled : he expresses doubts concerning that which he seems 
formerly to have regarded as established, and, with much 
caution, wishes for evidence confirmatory of his own, to show 
that the germs of Bacteria and Vibriones are killed in a boiling 
infusion of hay or turnip, as they have been proved to be in 
**Pasteur’s Solution” and in solutions containing ammonic 
tartrate and sodic phosphate 
With the view of removing this last source of doubt more 
effectually, and also of refuting the unwarrantable + conclusions 
of M. Pasteur, to the effect that the germs of Bacteria and 
Vib; iones are not killed in neutral or slightly alkaline fluids at a 
temperature of 212° F., I almost immediately after the reading 
of my last communication commenced a fresh series of experi- 
ments. é 
Nearly two years ago, in my ‘Modes of Origin of Lowest 
Organisms,” I brought forward evidence to show that Bacteria, 
Vibriones, and their supposed germs, are killed at a temperature 
of 140° F. (60° C.) in neutral or very faintly acid solutions con- 
taining ammonic tartrate and sodic phosphate, and also evidence 
tending to show that these living units were killed in neutral 
infusions of hay and in acid infusions of turnip at the same tem- 
perature. ; 
The crucial evidence adduced concerning the degree of heat 
destructive to Bacteria, Vibriones, and their germs, in the saline 
solution was of this nature. The solution had beén shown to be 
incapable of engendering Bacteria and Vibriones(underall ordinary 
conditions) after it had been boiled, although it still continued 
capable of supporting the life and encouraging the rapid multi- 
plication of any of these organisms which were purposely added 
toit. Some of this boiled solution, therefore, was introduced 
into flasks previously washed with boiling water ; and when the 
fluids had sufficiently cooled, that of each flask was inoculated 
with living Bacteria and Vibriones—in the proportion of one 
drop of a fluid quite turbid with these organisms to one fluid 
ounce of the clear saline solution. { These mixtures containing 
an abundance of living organisms were then heated to various 
temperatures, ranging from 122° F. (50° C) to 167° F. (75° C.), 
and it was invariably found that those which had been heated 
to 122° or 131° became quite turbid in about two days, whilst 
those which had been raised to 140° F. or upwards as invariably 
remained clear and unaltered. The turbidity in the first series 
having been ascertained to be due to the enormous multiplication 
of Bacteria and Vibriones, and it being a well-established fact 
that such organisms when undoubtedly living always rapidly 
multipiy in these fluids, the conclusion seemed almost inevitable 
that the organisms and their germs must have been killed in the 
flasks which were briefly subjected to the temperature of 140° F, 
How else are we to account for the fact that these fluids re- 
* See Report in Quart. Journ. of Microscop. Science, Oct. 1870. 
+ Reasons for this opinion have been fully set forth in ‘‘ The Beginnings 
of Life,’ p. vol. i. 374 e¢.seg. ; or the discriminating reader may at once 
find my justification forthis expression by reading pp. 58-66 of M. Pasteur’s 
memoir in Ann de Chim. et de Physique, 1862. : , 
Tt Fuller details concerning these experiments may be found in the little 
work already mentioned at pp. 51-56, and alsoin “The Beginnings of Life,” 
vol. i., pp 325-332, 
mained quite unaltered although living organisms were added to : 
them in the same proportion as they had been to those less- 
heated fluids which had so rapidly become turbid? Even if 
there does remain the mere possibility that the organisms and 
their supposed germs had not actually been killed, they were — 
certainly so far damaged as to be unable to manifest any vital 
characteristics. The heat had, at all events, deprived them of 
their powers of growth and multiplication, and these gone, so. 
little of what we are accustomed fo call ‘‘life” could remain, 
that practically they might well be considered as dead. And, as 
T shall subsequently show, the production of this potential death 
by the temperature of 140° F, enables us to draw just the same __| 
conclusions from other experiments, as if such a temperature had — 
produced a demonstrably actual death. Seeing also that these 
saline solutions were inoculated with a fluid in which Bacteria 
and Viériones were multiplying rapidly, we had a right to infer _ 
that they were multiplying in their accustomed manner, ‘as 
much by the known method of fission, as by any unknown and 
assumed method of reproduction.” So that, as I at the time 
said,* ‘‘ These experiments seem to show, therefore, that even if 
Bacteria do multiply by means of invisible gemmules, as well as 
by the known process of fission, such invisible particles possess — 
no higher power of resisting the destructive influence of heat 
than the parent Bacteria themselves possess.” 
This is, in fact, by far the most satisfactory kind of evidence 
that can be produced concerning the powers of resisting heat 
enjoyed by Sacteria and Vibriones, because it also meets the 
hypothesis as to their possible multiplication by invisible gem- 
mules possessed of a greater power of resisting heat, and because 
no mere inspection by the miscroscope of dead Aacteria can 
entitle us positively to affirm that they are dead, even though all 
characteristically vital or ‘‘true living” movements may be absent. 
Facts of a very similar nature were mentioned in-the same 
work, strongly tending to show that Bacteria and Vibriones are 
also killed at the same temperature in other fluids, such as infu- 
sions of hay or turnip. ‘These facts were referred to in the fol- 
lowing statement + :—“* Thus, if on the same slip, though under 
different covering-glasses, specimens of a hay-infusion turbid 
with #acteria are mounted, (a) without being heated, (4) after 
the fluid has been raised to 122° F. for ten minutes, and (c) after 
the fluid has been heated to 140° F. for ten minutes, it will be 
found that in the course of a few days the Bacteria under a and 
é have notably increased in quantity, while those under c do not 
become more numerous, however long the slide is kept. Facts 
of the same kind are observable if a turnip-infusion containing — 
living Bacteria is experimented with ; and the phenomena are in 
no way different if a solution of ammonic tartrate and sodic — 
phosphate (containing Bacteria) be employed instead of one of 
these vegetable infusions. The multiplication of the Bacteria 
beneath the covering-glass, when it occurs, is soon rendered 
obvious even to the naked eye by the increasing cloudiness of the 
film.” (Zo be continued.) 
Geological Society, March 12.—Joseph Prestwich, F.R.S., 
vice-president, in the chair. The following communications were 
read:—1. Note on some Brachiopoda collected by Mr. Judd 
from the Jurassic deposits of the East Coast of Scotland, by 
Thomas Davidson, F,R.S. In this note the author stated that 
four species of Brachiopoda collected by Mr. Judd were espe- 
cially worthy of notice, two of them being quire new, and two 
new to Britain. Three of them were obtained from the equiya- 
lent of the Kimmeridge clay, which was the more remarkable as 
the Brachiopoda of that formation are comparatively few. The 
new species described were Rhynchonelle Sutherlandi and Tere- 
bratula Foassi, derived, with Terebratula humeralis Rém., from 
the Upper Oolite of Garty in Sutherland ; the fourth species is 
Terebratula bisuffarcinata Schlot., from the Lower Calcareous 
Grit of Bramberry Hill. 2. On Solfataras and deposits of 
Sulphur at Kalamaki, near the Isthmus of Corinth, by Prof. D. 
T. Ansted, F.R.S. After noticing the traces of volcanic aetion 
east of the Pindus chain, the author described the Solfataras and 
sulphur-deposits of the neighbourhood of Kalamaki as furnishing 
indications that there is even now a real though subdued yoleanie 
energy in this part of Europe. 3. On the origin of clay-iron- 
stone, by Mr. J. Lucas, F.G.S. The author commenced by 
giving a general view of the varieties, chemical composition, and _ 
mode of occurrence of clay-ironstone, and suggested that the’ 
formation of all the bedded varieties may be explained by the 
* “ Modes of Origin of Lowest Organisms,” 1871, p. fo, 
+ Loc. cit, p. 60. 
