FOOTNOTES:

FOOTNOTES:1Those which are quite motionless are always in close apposition either with the under surface of the covering glass, or with the surface of the glass on which they are situated.2Phytopathologie, 1867. Hallier seems, however, strongly inclined to disbelieve in the origin of these organisms by Heterogenesis or by Archebiosis.3Sitzungsber. der K. Akad. zu Wien, 1870, Band lx., Heft iv.4Quarterly Journal of Microscopical Science, Oct., 1870.5Notwithstanding what Professor Huxley has said, I believe it to be almost certain that in many casesBacteriaexist in a solution in which there are neitherTorulænor developed fungi. And, on the other hand, I have seen fungi growing in a simple (boiled) solution of tartrate of ammonia, for weeks together, without the appearance ofBacteriaor the occurrence of any turbidity of the solution; and on two or three occasions I have seenTorulæswarming in an infusion without the presence ofBacteria.6Rendiconti del R. Istit. Lombardo, Ser. II. Vol. 1, p. 11.7However novel such a mode of origin of independentBacteriaandVibrionesmay appear to some, it will seem much less strange and unlikely to others who have seen, as I have done, anAmœba, or anActinophrys-like body, originate from the progressive molecular modifications taking place in a mass of chlorophyll and protoplasm within the filament of an alga. Many independent observers have watched all the stages of this process, and some have even seen Ciliated Infusoria originate by such a metamorphic change.8Or offcasts from pre-existing fungi,—constituting the “micrococci” of Professor Hallier.9From this view the transition is also easy, though none the less illegitimate, to the doctrine thatallfermentations are caused by organisms; just as it has been easy to start, and find converts for, the doctrine expressed by the phrase “omne vivum ex vivo.” The distinction betweenallandsomeis only too often overlooked.10‘Chimie organique,’ 1856, t. iv. p. 589.11Those who hold this opinion do not of course deny that living ferments can initiate fermentations. Every-day experience convinces them of the truth of this. They merely affirm that the intervention of vital action is not essential: they look upon fermentation as a purely chemical process, and believe that even in those cases where fermentation is initiated by living organisms (such as beer-yeast), these—although living—act chemically upon the matter which undergoes fermentation.12They may not believe this, because they may be unaware of the fact of the invariable association of some organisms with some kinds of fermentations, and may consequently have never concerned themselves with the evidence bearing upon this part of the question. (See Gerhardt,loc. cit.)13M. Pouchet and others had examined the dust whichsettleson objects, and amongst much débris of different kinds had found comparatively few ova or spores. He had not, however, up to this time, filtered the air, so as to see what germs might be detected floating about in the atmosphere.14‘Anat. et Physiol. compar.’ t. viii. p. 264.15‘Annales de Chimie et de Physique,’ 1862, t. lxiv. p. 24.16Those which he believed to be eggs of ciliated infusoria, may be at once dismissed from consideration, as we are not at present concerned with the origin of organisms of this kind.17Loc. cit.p. 34, note1.18Loc cit.p. 56.19See p. 57.20M. Pasteur’s use of this term, in which he is followed by others holding similar opinions, is much to be deprecated. Having said that he had found certain corpuscles which resembled spores of fungi, or ova of infusoria, he subsequently speaks of them as “germs,” and also applies the same name to the reproductive particles ofBacteria, which he merelyassumesto be present in the atmosphere. Thus, having only proved that corpuscles resembling spores of some fungi, are to be found in the atmosphere, he subsequently speaks of the presence of a multitude of atmospheric germs as an established fact, without at all prominently pointing out that, so far as the most important of these are concerned—germs ofBacteria—their existence had only been inferred, and not proved.21‘Philosophical Transactions,’ 1866, pp. 616–619.22The solution, during the whole time, being exposed to a temperature of 75° to 85° F.23As expressed, the proposition may be an approximation to the truth. M. Pasteur, however, really endeavours to lead his readers to believe that the “solid particles” which are efficacious, are, in all cases, living “germs.”24‘Nature,’ 1870, No. 36, p. 193.25If his reasonings can be shown to be quite inconclusive, and if his results can be otherwise explained, some people may, at last, begin to recognize that their blind and mistaken faith in M. Pasteur’s work has been somewhat misplaced.26M. Pasteur attempted to make a distinction in the case of slightly alkaline or neutral fluids (loc. cit., pp. 60–65). I have endeavoured to show the untenability of his conclusion in ‘Nature,’ 1870, No. 37, pp. 224–227.27‘Nature,’ 1870, No. 35, p. 171.28I always employ a solution of gum mastic and bismuth in chloroform. If a different varnish be employed, it is of course necessary to ascertain whether its application is injurious to the enclosedBacteria.29If an unboiled specimen of milk be mounted, a multiplication of living particles takes place here and there amongst the fat globules, just as the multiplication ofBacteriaoccurs in a vegetable infusion; but in the boiled specimen no trace of such multiplication can ever be detected.30Those particles which come to rest, in such cases, are always in contact with one or other of the contiguous surfaces of glass.31The specific gravity of the fluid being constant. Where this is dense or viscid, as with glycerine, Brownian movements do not occur at all.32In the proportion of ten grains of neutral ammonic tartrate, with three grains of neutral sodic phosphate, to an ounce of distilled water.33It was necessary to boil the solution first, in order to destroy any living things or dead ferments which it might contain. It must contain one or the other, because an unboiled solution of this kind, in a corked bottle about half full, will always become turbid; whilst, after it has been boiled, it may be kept indefinitely under similar conditions without becoming turbid.34The proportion was one drop of the fluid, opaque with organisms, to an ounce of the clear solution.35Into which a piece of glass tube had been slipped to prevent collapse.36Allowing even five minutes for the temperature of the 1 oz. of fluid to become equal to that of the bath, it would then have remained exposed to this amount of heat for about ten minutes.37Fluids which had remained sterile would always, in the course of thirty-six or forty-eight hours after inoculation with livingBacteria, become more or less turbid.38There is, however, another point of extreme interest in connection with these experiments, bearing upon the supposed universal distribution of “germs” ofBacteriaand other organisms, which I will now mention. One of the flasks, which had been exposed to 140° F., and which had been hermetically sealed at this temperature, had its neck cracked (accidentally) about half an hour afterwards. Thinking it would be as well, notwithstanding this, to keep it and observe the result, its bulb was immersed in the same water-bath with the other flasks which had been prepared at the same time. Whilst the fluid in one of these which had been exposed to a heat of 131° F., became turbid in the course of a few days, this, which had been exposed to a heat of 140° F. and whose neck was also extensively cracked, remained quite clear for seven days, although to such an extent exposed to the access of germs. Its eminent suitability for nourishing the germs of such organisms was also shown, because, on the seventh day, the fluid being still clear, the blade of a penknife was dipped into it, after having been previously immersed in a solution containing livingBacteriaandTorulæ, and in thirty-six hours after this inoculation, the fluid had become turbid, owing to the presence of myriads of these organisms. So that even where obvious cracks occur, and the vacuum is altogether impaired by the consequent inrush of air, such air does not necessarily carry with it germs ofBacteria—which have been supposed to be universally diffused, and capable of passing through cracks so minute as to be invisible. These results, important as they are, have not at all surprised me, because one may frequently find a previously boiled solution of the kind under consideration, remaining free from turbidity for two weeks or more, although the neck of the flask has been merely covered by a loose paper-cap (see p.30).39‘Nouvelles Expériences,’ etc., 1864, p. 38.40‘American Journal of Science and Arts,’ Oct. 1867.41During nearly the whole of the time the temperature was kept at 113° F. It only rose to the higher temperature for about ten minutes.42TheBacteriaandVibrioneswith which Professor Wyman experimented were derived from different sources; and so far as I also have been able to ascertain, theBacteriaof different fluids are similarly affected by exposure to similar degrees of heat. Thus, if on the same slip, though under different covering glasses, specimens of a hay infusion, turbid withBacteria, are mounted, (a) without being heated, (b) 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, theBacteriaunderaandbhave notably increased in quantity, whilst those undercdo not become more numerous, however long the slide is kept. Facts of the same kind are observable if a turnip infusion, containing livingBacteria, is experimented with; and the phenomena are in no way different if a solution of ammonic tartrate and sodic phosphate (containingBacteria) be employed instead of one of these vegetable infusions. The multiplication of theBacteriabeneath the covering-glass, when it occurs, is soon rendered obvious, even to the naked eye, by the increasing cloudiness of the film.43‘Compt. Rend.,’ t. lxi. p. 1060.44When boiled solutions, containing mannite, with a little nitrate and phosphate of ammonia, were employed, they always remained sterile. Similar negative results followed the employment of ox-gall. Of three decoctions of beef with which M. Meunier experimented, the two stronger of them were found to contain swarms ofBacteriain about twelve days. Of three other flasks containing boiled urine, two also proved fertile.45I have employed flasks of about11/2oz. in capacity, provided with necks two feet in length. In each case, after the flask has been half filled with the fluid, the neck has been bent eight times at an acute angle.46These are the only experiments which I have performed with the very long plugs of cotton-wool, though in other previous trials with plugs about11/2in. long, I have several times obtained positive results.47When infusions have been employed, these have all been made as strong as possible, and have been filtered before use.Warmwater has been added in quantity just sufficient to cover the substance to be infused (cut into very small pieces), and the mixture has then been kept at a temperature of from 110°–130° F. for three or four hours.48Flask still in my possession, unopened.49Flask still in my possession, unopened.50The vapour had lost all odour of turnip. Some of the fluid which splashed over was found to be still slightly acid.51This experiment is very interesting in two or three respects. A neck of half the usual length—with only four bendings—sufficed to preserve the fluid for several days; and when this fluid (which had been in the bent-neck apparatus for nine days) was sealed up in the same flask during ebullition, it remainedin vacuofor thirteen days without undergoing any apparent change, and then only became turbid under the influence of a higher temperature. Yet some of the same fluid, in a flask which was hermetically sealed during the first ebullition (No. XV.) behaved as such an infusion usually does, and became quite turbid in forty-eight hours.52Flask still in my possession, unopened.53The filtered infusion of turnip was neutralized by liquor potassæ. The cheese (Cheddar) was new and not in the least mouldy.54The fluid itself being somewhat opaque, the first stages of increased turbidity from presence ofBacteriacould not be detected.55This again is a most instructive experiment when compared with Nos. XVI. and XX., in which portions of the same infusion were employed. The results in No. IX. would lead us to believe that a vegetable infusion which does not ferment, does, nevertheless, undergo some changes in molecular composition, and this notion seems to derive confirmation from the present experiment. Some of the same solution which has been kept for a time (twelve days) from contact with atmospheric particles, subsequently, even when fully exposed to the air, undergoes no apparent change for six days, and then, instead of becoming filled withBacteria, swarms only withTorulæ. Yet the infusion in this condition was perfectly capable of nourishingBacteria, as I subsequently proved by inoculating it. Why then was it not inoculated by the livingBacteria, with which the air is thought by some to be teeming?56Some of the same fluid, exposed in a similar flask, without previous boiling, became turbid in eight hours, and lighter in colour; whilst, after twenty hours, the turbidity was extremely well-marked.57The condition of the fluid, and the nature of its contents, were very similar to that met with in No. XXI.58Still in my possession, unopened. In all probability the flocculi which formed would be found to be similar in their microscopical, as they certainly were in their naked-eye characters, to those met with in No. XXXV.59Experiment No. 8, recorded in ‘Nature,’ 1870, No. 36, p. 194, may be compared with this and No. XXXIII.60This experiment should be compared with Nos. XVIII. and XXXIII. It seems to show that if some fermentable fluids can be kept for a time under conditions in which they will not ferment, the constitution of the fluid, instead of remaining the same, undergoes a slow alteration by which it is rendered absolutely less fermentable, even when exposed to the most favouring influences.61After this experiment had been completed, a fresh-filtered infusion of turnip was placed in the same flask (having the neck open just beyond its second bending), and after having been boiled for a few minutes it was immersed in the same water-bath. This fluid became turbid in thirty-six hours, and was then found to contain multitudes ofBacteria; and the characteristic odour of the turnip infusion was still appreciable.62The results of this experiment are most interesting, especially if compared with what takes place when some of the same fluid is neutralized by ammonic carbonate (No. XXXIV.), with what occurs when a similar fluid (as in No. XXX.) is contained in a flask sealed during the continuance of ebullition, or also with what occurred in Nos. XIII. and XXXII. In the present case the second boiling seems to have destroyed what small amount of fermentability there was still remaining in the solution; but in No. IX. fermentation did take place after the second boiling—though this occurred only under the influence of diminished pressure and a higher temperature.63Some of same as that which was used (unaltered) in last experiment.64It had been rendered turbid from the first, by the carbolic acid.65The fluid had been rendered paler and turbid from the first, by the addition of the carbolic acid.66The alteration in colour was less marked than in the similar mixture which had not been boiled, though the turbidity was just as obvious.67This fluid was whitish, and somewhat opaque, from the first.68For other experiments showing a similar sterility, induced by a slight acidification with acetic acid, see ‘Nature,’ 1870, No. 37, pp. 226 and 227.69The results of this experiment, and of No. LXIII. are decidedly opposed to the reality of the germ-killing powers with which carbolic acid has been endowed by Professor Lister and others. I, however, had previously found that specimens ofTorulæandBacteria, obtained from freshly opened flasks, and then mounted as microscopical specimens in a mixture of glycerine and carbolic acid (in the proportion of 15:1), not unfrequently grew and multiplied under such conditions. MM. Béchamp and Estor, also found thatBacteriamultiplied in carbolized fluids, and similar facts have been testified to by some Italian observers. But, organic fluids differ much from one another, so that the influence of carbolic acid may well be different upon different fluids. And, accordingly, we find that whilst its addition to, and subsequent boiling with, a hay infusion increases the fermentability of this, precisely the opposite effects are produced when the hay is replaced by a turnip infusion (see No. XLV.). Without wishing to undervalue in the least the system of treatment introduced, and so admirably carried out by Professor Lister, I am strongly of opinion that he explains his results by theories which are almost wholly incorrect.70All the simple ammoniacal solutions were in the proportion of ten grains of the salt to the fluid ounce of distilled water; and to those which also contained sodic phosphate, three grains of this were added. About half an ounce of each solution was put into a one-ounce wide-mouthed bottle, and then tightly corked.71On comparing the corresponding experiments of series XLVIII.–LI. with those of series LIII.–LVI. less difference is found than might have been expected by many. The comparison of the numbers of each series with one another, also reveals the interesting fact, that the mere presence of N, C, O, and H, is not all that is required, even for the growth and nutrition of the lower living things. These elements seem to lapse into the new combinations constituting living matter of various kinds, more easily from certain pre-existing states of combination than from others. Solutions of ammonic tartrate are much more favourable starting points for the new combinations than solutions of ammonic acetate. The comparison of experiment No. LI. with No. LII. is extremely interesting in reference to the dogma that phosphorus is a necessary ingredient in living matter. Solutions of the ammonic tartrate in distilled water have been twice analyzed for me by a skilled chemist, without revealing the least trace either of phosphorus or sulphur. This result is very remarkable when compared with the amount of living matter which may so soon appear in such a solution: the number of the organisms and the rapidity of their evolution, being almost equal to that which occurs in a similar solution to which a phosphate has been added. However much, therefore, phosphorus may aid the development of organisms in many fluids, there is still an important difference betweenmanyandall, which if more frequently borne in mind, would render universal propositions more scarce (see ‘Journal of Chemical Society,’ March, 1871, pp. 72–74). The truth of the dictum “Ohne Phosphor gar kein Leben,” is, I venture to think, far from being proved. If on insufficient evidence (referring only to particular fluids) such a dictum is arrived at; and if then, the presence of organisms in any fluid is to be taken as evidence of the existence of phosphorus (even though this cannot be otherwise substantiated), the case of phosphorus in relation to Life comes to be similar to the case of the much abused germs.Mutato nomine, de teFabula narratur.72The fluids were boiled at the low temperature, with the aid of an air-pump, merely in order to be able to procure a more perfect vacuum in the flasks; these experiments being destined to show whether the simple (uninoculated) solutions would become turbidin vacuo—that is to say, without the oxidizing influence of the air—when they had not been exposed to an amount of heat sufficient to destroy any living or dead ferments which they might contain.73A deposit of this kind is almost invariably found in such solutions after their fermentability has been lowered by previous boiling. Growth takes place very slowly in these cases, and also when similar boiled fluids are containedin vacuo.74Loc. cit. p. 71.75Loc. cit. pp. 75 and 76.76Loc. cit. pp. 83 and 84.77The subsidence of the atmospheric particles has been ably demonstrated by Professor Tyndall.—See ‘Nature,’ 1870.78See M. Pouchet’s ‘Nouvelles Expériences sur la Génération Spontanée,’ &c., p. 69.79See various communications in ‘Compt. Rend.’ (1863), t. LVII.80Loc. cit., p. 40.81Speaking of experiments in closed flasks, in which the air has been either calcined or filtered, Gerhardt (‘Chimie Organique,’ t. IV. p. 545) says:—“Si dans les premières expériences l’air calciné ou tamisé s’est montré beaucoup moins actif que l’air non soumis à ce traitement, c’est que la chaleur rouge ou le tamisage enlève à l’air non seulement les germes des infusoires et des moisissures, mais encore les débris des matières en décomposition qui y sont suspendues, c’est-à-dire les ferments dont l’activité viendrait s’ajouter à celle de l’oxygène de l’air.”82On what other supposition can one explain the results of experiments LVII.–LXV., and of others alluded to on p.100?83See notes on pp.73and79. It was not that these fluids were incapable of being inoculated, or that they were unsuitable for the development of the lower forms of life, as was shown by their subsequent fate, and by the fact that they can always speedily be made to become turbid if they are really inoculated with livingBacteria. Almost similar facts in opposition to the prevalent Panspermic views have been noted by Professor Cantoni (Rend. del R. Istit. Lombardo, Novembre, 1869). He found (as I have also frequently found) that when fluids had been subjected to the influence of high temperatures, and had subsequently remained sterile in closed flasks, they might be freely exposed to the air for one or two weeks, or more, without becoming turbid—although at any time a general turbidity could be speedily induced, by introducing a few livingBacteriainto the fluid.84‘On the Direct Correlation of Mechanical and Chemical Forces.’—Proceedings of the Royal Society, vol. xii. pp. 539 and 546.85‘Traité de Physiologie.’ Translated by Jourdan. 1837. t. i., p. 18.86‘American Journal of Science,’ July, 1862.87See Gerhardt’s, ‘Chimie Organique,’ t. iv. pp. 540 and 547.88It was, indeed, the consideration of these latter facts which originally forced Gay-Lussac to the conclusion, that fermentation would not take placein vacuo, or without the presence of free oxygen, which was and still is, believed by many, to be the immediate determining cause of fermentation.89This proof is more severe in certain other experiments (not yet published) in which I had the benefit of Professor Frankland’s assistance. The vacuum in these cases was perhaps more perfect, having been procured by means of a Sprengel’s pump and a simultaneous ebullition of the fluid, during which the flasks were hermetically sealed. The closed flasks were subsequently exposed to a temperature of 293° F. for a short time.90An examination of tins of “perfectly good” meats has convinced me that a very small number ofBacteriaandLeptothrixfilaments are occasionally to be met with.91It has, however, been ascertained by M. Pouchet, that beer-yeast, even after prolonged ebullition, will undergo change in a flask which is full and hermetically sealed; and the manufacturers of preserved meats also find that occasionally, in some of their best prepared tins, the meats become putrid, and that the putridity is accompanied by the presence of organisms. Some fermentations are doubtless attended by a less copious emission of waste gases than that which characterizes other fermentations; and some fermentations will progress in spite of a moderate amount of pressure.

1Those which are quite motionless are always in close apposition either with the under surface of the covering glass, or with the surface of the glass on which they are situated.

2Phytopathologie, 1867. Hallier seems, however, strongly inclined to disbelieve in the origin of these organisms by Heterogenesis or by Archebiosis.

3Sitzungsber. der K. Akad. zu Wien, 1870, Band lx., Heft iv.

4Quarterly Journal of Microscopical Science, Oct., 1870.

5Notwithstanding what Professor Huxley has said, I believe it to be almost certain that in many casesBacteriaexist in a solution in which there are neitherTorulænor developed fungi. And, on the other hand, I have seen fungi growing in a simple (boiled) solution of tartrate of ammonia, for weeks together, without the appearance ofBacteriaor the occurrence of any turbidity of the solution; and on two or three occasions I have seenTorulæswarming in an infusion without the presence ofBacteria.

6Rendiconti del R. Istit. Lombardo, Ser. II. Vol. 1, p. 11.

7However novel such a mode of origin of independentBacteriaandVibrionesmay appear to some, it will seem much less strange and unlikely to others who have seen, as I have done, anAmœba, or anActinophrys-like body, originate from the progressive molecular modifications taking place in a mass of chlorophyll and protoplasm within the filament of an alga. Many independent observers have watched all the stages of this process, and some have even seen Ciliated Infusoria originate by such a metamorphic change.

8Or offcasts from pre-existing fungi,—constituting the “micrococci” of Professor Hallier.

9From this view the transition is also easy, though none the less illegitimate, to the doctrine thatallfermentations are caused by organisms; just as it has been easy to start, and find converts for, the doctrine expressed by the phrase “omne vivum ex vivo.” The distinction betweenallandsomeis only too often overlooked.

10‘Chimie organique,’ 1856, t. iv. p. 589.

11Those who hold this opinion do not of course deny that living ferments can initiate fermentations. Every-day experience convinces them of the truth of this. They merely affirm that the intervention of vital action is not essential: they look upon fermentation as a purely chemical process, and believe that even in those cases where fermentation is initiated by living organisms (such as beer-yeast), these—although living—act chemically upon the matter which undergoes fermentation.

12They may not believe this, because they may be unaware of the fact of the invariable association of some organisms with some kinds of fermentations, and may consequently have never concerned themselves with the evidence bearing upon this part of the question. (See Gerhardt,loc. cit.)

13M. Pouchet and others had examined the dust whichsettleson objects, and amongst much débris of different kinds had found comparatively few ova or spores. He had not, however, up to this time, filtered the air, so as to see what germs might be detected floating about in the atmosphere.

14‘Anat. et Physiol. compar.’ t. viii. p. 264.

15‘Annales de Chimie et de Physique,’ 1862, t. lxiv. p. 24.

16Those which he believed to be eggs of ciliated infusoria, may be at once dismissed from consideration, as we are not at present concerned with the origin of organisms of this kind.

17Loc. cit.p. 34, note1.

18Loc cit.p. 56.

19See p. 57.

20M. Pasteur’s use of this term, in which he is followed by others holding similar opinions, is much to be deprecated. Having said that he had found certain corpuscles which resembled spores of fungi, or ova of infusoria, he subsequently speaks of them as “germs,” and also applies the same name to the reproductive particles ofBacteria, which he merelyassumesto be present in the atmosphere. Thus, having only proved that corpuscles resembling spores of some fungi, are to be found in the atmosphere, he subsequently speaks of the presence of a multitude of atmospheric germs as an established fact, without at all prominently pointing out that, so far as the most important of these are concerned—germs ofBacteria—their existence had only been inferred, and not proved.

21‘Philosophical Transactions,’ 1866, pp. 616–619.

22The solution, during the whole time, being exposed to a temperature of 75° to 85° F.

23As expressed, the proposition may be an approximation to the truth. M. Pasteur, however, really endeavours to lead his readers to believe that the “solid particles” which are efficacious, are, in all cases, living “germs.”

24‘Nature,’ 1870, No. 36, p. 193.

25If his reasonings can be shown to be quite inconclusive, and if his results can be otherwise explained, some people may, at last, begin to recognize that their blind and mistaken faith in M. Pasteur’s work has been somewhat misplaced.

26M. Pasteur attempted to make a distinction in the case of slightly alkaline or neutral fluids (loc. cit., pp. 60–65). I have endeavoured to show the untenability of his conclusion in ‘Nature,’ 1870, No. 37, pp. 224–227.

27‘Nature,’ 1870, No. 35, p. 171.

28I always employ a solution of gum mastic and bismuth in chloroform. If a different varnish be employed, it is of course necessary to ascertain whether its application is injurious to the enclosedBacteria.

29If an unboiled specimen of milk be mounted, a multiplication of living particles takes place here and there amongst the fat globules, just as the multiplication ofBacteriaoccurs in a vegetable infusion; but in the boiled specimen no trace of such multiplication can ever be detected.

30Those particles which come to rest, in such cases, are always in contact with one or other of the contiguous surfaces of glass.

31The specific gravity of the fluid being constant. Where this is dense or viscid, as with glycerine, Brownian movements do not occur at all.

32In the proportion of ten grains of neutral ammonic tartrate, with three grains of neutral sodic phosphate, to an ounce of distilled water.

33It was necessary to boil the solution first, in order to destroy any living things or dead ferments which it might contain. It must contain one or the other, because an unboiled solution of this kind, in a corked bottle about half full, will always become turbid; whilst, after it has been boiled, it may be kept indefinitely under similar conditions without becoming turbid.

34The proportion was one drop of the fluid, opaque with organisms, to an ounce of the clear solution.

35Into which a piece of glass tube had been slipped to prevent collapse.

36Allowing even five minutes for the temperature of the 1 oz. of fluid to become equal to that of the bath, it would then have remained exposed to this amount of heat for about ten minutes.

37Fluids which had remained sterile would always, in the course of thirty-six or forty-eight hours after inoculation with livingBacteria, become more or less turbid.

38There is, however, another point of extreme interest in connection with these experiments, bearing upon the supposed universal distribution of “germs” ofBacteriaand other organisms, which I will now mention. One of the flasks, which had been exposed to 140° F., and which had been hermetically sealed at this temperature, had its neck cracked (accidentally) about half an hour afterwards. Thinking it would be as well, notwithstanding this, to keep it and observe the result, its bulb was immersed in the same water-bath with the other flasks which had been prepared at the same time. Whilst the fluid in one of these which had been exposed to a heat of 131° F., became turbid in the course of a few days, this, which had been exposed to a heat of 140° F. and whose neck was also extensively cracked, remained quite clear for seven days, although to such an extent exposed to the access of germs. Its eminent suitability for nourishing the germs of such organisms was also shown, because, on the seventh day, the fluid being still clear, the blade of a penknife was dipped into it, after having been previously immersed in a solution containing livingBacteriaandTorulæ, and in thirty-six hours after this inoculation, the fluid had become turbid, owing to the presence of myriads of these organisms. So that even where obvious cracks occur, and the vacuum is altogether impaired by the consequent inrush of air, such air does not necessarily carry with it germs ofBacteria—which have been supposed to be universally diffused, and capable of passing through cracks so minute as to be invisible. These results, important as they are, have not at all surprised me, because one may frequently find a previously boiled solution of the kind under consideration, remaining free from turbidity for two weeks or more, although the neck of the flask has been merely covered by a loose paper-cap (see p.30).

39‘Nouvelles Expériences,’ etc., 1864, p. 38.

40‘American Journal of Science and Arts,’ Oct. 1867.

41During nearly the whole of the time the temperature was kept at 113° F. It only rose to the higher temperature for about ten minutes.

42TheBacteriaandVibrioneswith which Professor Wyman experimented were derived from different sources; and so far as I also have been able to ascertain, theBacteriaof different fluids are similarly affected by exposure to similar degrees of heat. Thus, if on the same slip, though under different covering glasses, specimens of a hay infusion, turbid withBacteria, are mounted, (a) without being heated, (b) 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, theBacteriaunderaandbhave notably increased in quantity, whilst those undercdo not become more numerous, however long the slide is kept. Facts of the same kind are observable if a turnip infusion, containing livingBacteria, is experimented with; and the phenomena are in no way different if a solution of ammonic tartrate and sodic phosphate (containingBacteria) be employed instead of one of these vegetable infusions. The multiplication of theBacteriabeneath the covering-glass, when it occurs, is soon rendered obvious, even to the naked eye, by the increasing cloudiness of the film.

43‘Compt. Rend.,’ t. lxi. p. 1060.

44When boiled solutions, containing mannite, with a little nitrate and phosphate of ammonia, were employed, they always remained sterile. Similar negative results followed the employment of ox-gall. Of three decoctions of beef with which M. Meunier experimented, the two stronger of them were found to contain swarms ofBacteriain about twelve days. Of three other flasks containing boiled urine, two also proved fertile.

45I have employed flasks of about11/2oz. in capacity, provided with necks two feet in length. In each case, after the flask has been half filled with the fluid, the neck has been bent eight times at an acute angle.

46These are the only experiments which I have performed with the very long plugs of cotton-wool, though in other previous trials with plugs about11/2in. long, I have several times obtained positive results.

47When infusions have been employed, these have all been made as strong as possible, and have been filtered before use.Warmwater has been added in quantity just sufficient to cover the substance to be infused (cut into very small pieces), and the mixture has then been kept at a temperature of from 110°–130° F. for three or four hours.

48Flask still in my possession, unopened.

49Flask still in my possession, unopened.

50The vapour had lost all odour of turnip. Some of the fluid which splashed over was found to be still slightly acid.

51This experiment is very interesting in two or three respects. A neck of half the usual length—with only four bendings—sufficed to preserve the fluid for several days; and when this fluid (which had been in the bent-neck apparatus for nine days) was sealed up in the same flask during ebullition, it remainedin vacuofor thirteen days without undergoing any apparent change, and then only became turbid under the influence of a higher temperature. Yet some of the same fluid, in a flask which was hermetically sealed during the first ebullition (No. XV.) behaved as such an infusion usually does, and became quite turbid in forty-eight hours.

52Flask still in my possession, unopened.

53The filtered infusion of turnip was neutralized by liquor potassæ. The cheese (Cheddar) was new and not in the least mouldy.

54The fluid itself being somewhat opaque, the first stages of increased turbidity from presence ofBacteriacould not be detected.

55This again is a most instructive experiment when compared with Nos. XVI. and XX., in which portions of the same infusion were employed. The results in No. IX. would lead us to believe that a vegetable infusion which does not ferment, does, nevertheless, undergo some changes in molecular composition, and this notion seems to derive confirmation from the present experiment. Some of the same solution which has been kept for a time (twelve days) from contact with atmospheric particles, subsequently, even when fully exposed to the air, undergoes no apparent change for six days, and then, instead of becoming filled withBacteria, swarms only withTorulæ. Yet the infusion in this condition was perfectly capable of nourishingBacteria, as I subsequently proved by inoculating it. Why then was it not inoculated by the livingBacteria, with which the air is thought by some to be teeming?

56Some of the same fluid, exposed in a similar flask, without previous boiling, became turbid in eight hours, and lighter in colour; whilst, after twenty hours, the turbidity was extremely well-marked.

57The condition of the fluid, and the nature of its contents, were very similar to that met with in No. XXI.

58Still in my possession, unopened. In all probability the flocculi which formed would be found to be similar in their microscopical, as they certainly were in their naked-eye characters, to those met with in No. XXXV.

59Experiment No. 8, recorded in ‘Nature,’ 1870, No. 36, p. 194, may be compared with this and No. XXXIII.

60This experiment should be compared with Nos. XVIII. and XXXIII. It seems to show that if some fermentable fluids can be kept for a time under conditions in which they will not ferment, the constitution of the fluid, instead of remaining the same, undergoes a slow alteration by which it is rendered absolutely less fermentable, even when exposed to the most favouring influences.

61After this experiment had been completed, a fresh-filtered infusion of turnip was placed in the same flask (having the neck open just beyond its second bending), and after having been boiled for a few minutes it was immersed in the same water-bath. This fluid became turbid in thirty-six hours, and was then found to contain multitudes ofBacteria; and the characteristic odour of the turnip infusion was still appreciable.

62The results of this experiment are most interesting, especially if compared with what takes place when some of the same fluid is neutralized by ammonic carbonate (No. XXXIV.), with what occurs when a similar fluid (as in No. XXX.) is contained in a flask sealed during the continuance of ebullition, or also with what occurred in Nos. XIII. and XXXII. In the present case the second boiling seems to have destroyed what small amount of fermentability there was still remaining in the solution; but in No. IX. fermentation did take place after the second boiling—though this occurred only under the influence of diminished pressure and a higher temperature.

63Some of same as that which was used (unaltered) in last experiment.

64It had been rendered turbid from the first, by the carbolic acid.

65The fluid had been rendered paler and turbid from the first, by the addition of the carbolic acid.

66The alteration in colour was less marked than in the similar mixture which had not been boiled, though the turbidity was just as obvious.

67This fluid was whitish, and somewhat opaque, from the first.

68For other experiments showing a similar sterility, induced by a slight acidification with acetic acid, see ‘Nature,’ 1870, No. 37, pp. 226 and 227.

69The results of this experiment, and of No. LXIII. are decidedly opposed to the reality of the germ-killing powers with which carbolic acid has been endowed by Professor Lister and others. I, however, had previously found that specimens ofTorulæandBacteria, obtained from freshly opened flasks, and then mounted as microscopical specimens in a mixture of glycerine and carbolic acid (in the proportion of 15:1), not unfrequently grew and multiplied under such conditions. MM. Béchamp and Estor, also found thatBacteriamultiplied in carbolized fluids, and similar facts have been testified to by some Italian observers. But, organic fluids differ much from one another, so that the influence of carbolic acid may well be different upon different fluids. And, accordingly, we find that whilst its addition to, and subsequent boiling with, a hay infusion increases the fermentability of this, precisely the opposite effects are produced when the hay is replaced by a turnip infusion (see No. XLV.). Without wishing to undervalue in the least the system of treatment introduced, and so admirably carried out by Professor Lister, I am strongly of opinion that he explains his results by theories which are almost wholly incorrect.

70All the simple ammoniacal solutions were in the proportion of ten grains of the salt to the fluid ounce of distilled water; and to those which also contained sodic phosphate, three grains of this were added. About half an ounce of each solution was put into a one-ounce wide-mouthed bottle, and then tightly corked.

71On comparing the corresponding experiments of series XLVIII.–LI. with those of series LIII.–LVI. less difference is found than might have been expected by many. The comparison of the numbers of each series with one another, also reveals the interesting fact, that the mere presence of N, C, O, and H, is not all that is required, even for the growth and nutrition of the lower living things. These elements seem to lapse into the new combinations constituting living matter of various kinds, more easily from certain pre-existing states of combination than from others. Solutions of ammonic tartrate are much more favourable starting points for the new combinations than solutions of ammonic acetate. The comparison of experiment No. LI. with No. LII. is extremely interesting in reference to the dogma that phosphorus is a necessary ingredient in living matter. Solutions of the ammonic tartrate in distilled water have been twice analyzed for me by a skilled chemist, without revealing the least trace either of phosphorus or sulphur. This result is very remarkable when compared with the amount of living matter which may so soon appear in such a solution: the number of the organisms and the rapidity of their evolution, being almost equal to that which occurs in a similar solution to which a phosphate has been added. However much, therefore, phosphorus may aid the development of organisms in many fluids, there is still an important difference betweenmanyandall, which if more frequently borne in mind, would render universal propositions more scarce (see ‘Journal of Chemical Society,’ March, 1871, pp. 72–74). The truth of the dictum “Ohne Phosphor gar kein Leben,” is, I venture to think, far from being proved. If on insufficient evidence (referring only to particular fluids) such a dictum is arrived at; and if then, the presence of organisms in any fluid is to be taken as evidence of the existence of phosphorus (even though this cannot be otherwise substantiated), the case of phosphorus in relation to Life comes to be similar to the case of the much abused germs.Mutato nomine, de teFabula narratur.

Mutato nomine, de teFabula narratur.

72The fluids were boiled at the low temperature, with the aid of an air-pump, merely in order to be able to procure a more perfect vacuum in the flasks; these experiments being destined to show whether the simple (uninoculated) solutions would become turbidin vacuo—that is to say, without the oxidizing influence of the air—when they had not been exposed to an amount of heat sufficient to destroy any living or dead ferments which they might contain.

73A deposit of this kind is almost invariably found in such solutions after their fermentability has been lowered by previous boiling. Growth takes place very slowly in these cases, and also when similar boiled fluids are containedin vacuo.

74Loc. cit. p. 71.

75Loc. cit. pp. 75 and 76.

76Loc. cit. pp. 83 and 84.

77The subsidence of the atmospheric particles has been ably demonstrated by Professor Tyndall.—See ‘Nature,’ 1870.

78See M. Pouchet’s ‘Nouvelles Expériences sur la Génération Spontanée,’ &c., p. 69.

79See various communications in ‘Compt. Rend.’ (1863), t. LVII.

80Loc. cit., p. 40.

81Speaking of experiments in closed flasks, in which the air has been either calcined or filtered, Gerhardt (‘Chimie Organique,’ t. IV. p. 545) says:—“Si dans les premières expériences l’air calciné ou tamisé s’est montré beaucoup moins actif que l’air non soumis à ce traitement, c’est que la chaleur rouge ou le tamisage enlève à l’air non seulement les germes des infusoires et des moisissures, mais encore les débris des matières en décomposition qui y sont suspendues, c’est-à-dire les ferments dont l’activité viendrait s’ajouter à celle de l’oxygène de l’air.”

82On what other supposition can one explain the results of experiments LVII.–LXV., and of others alluded to on p.100?

83See notes on pp.73and79. It was not that these fluids were incapable of being inoculated, or that they were unsuitable for the development of the lower forms of life, as was shown by their subsequent fate, and by the fact that they can always speedily be made to become turbid if they are really inoculated with livingBacteria. Almost similar facts in opposition to the prevalent Panspermic views have been noted by Professor Cantoni (Rend. del R. Istit. Lombardo, Novembre, 1869). He found (as I have also frequently found) that when fluids had been subjected to the influence of high temperatures, and had subsequently remained sterile in closed flasks, they might be freely exposed to the air for one or two weeks, or more, without becoming turbid—although at any time a general turbidity could be speedily induced, by introducing a few livingBacteriainto the fluid.

84‘On the Direct Correlation of Mechanical and Chemical Forces.’—Proceedings of the Royal Society, vol. xii. pp. 539 and 546.

85‘Traité de Physiologie.’ Translated by Jourdan. 1837. t. i., p. 18.

86‘American Journal of Science,’ July, 1862.

87See Gerhardt’s, ‘Chimie Organique,’ t. iv. pp. 540 and 547.

88It was, indeed, the consideration of these latter facts which originally forced Gay-Lussac to the conclusion, that fermentation would not take placein vacuo, or without the presence of free oxygen, which was and still is, believed by many, to be the immediate determining cause of fermentation.

89This proof is more severe in certain other experiments (not yet published) in which I had the benefit of Professor Frankland’s assistance. The vacuum in these cases was perhaps more perfect, having been procured by means of a Sprengel’s pump and a simultaneous ebullition of the fluid, during which the flasks were hermetically sealed. The closed flasks were subsequently exposed to a temperature of 293° F. for a short time.

90An examination of tins of “perfectly good” meats has convinced me that a very small number ofBacteriaandLeptothrixfilaments are occasionally to be met with.

91It has, however, been ascertained by M. Pouchet, that beer-yeast, even after prolonged ebullition, will undergo change in a flask which is full and hermetically sealed; and the manufacturers of preserved meats also find that occasionally, in some of their best prepared tins, the meats become putrid, and that the putridity is accompanied by the presence of organisms. Some fermentations are doubtless attended by a less copious emission of waste gases than that which characterizes other fermentations; and some fermentations will progress in spite of a moderate amount of pressure.

Back to Index Next