Chapter XXI: Appendix

Whilst this work was passing through the press there appeared two small works on the subject of the generation of inferior organisms.

One of them was by M. Fremy. The author’s object seems to have been merely to give an account, under a new form, of the part which he took in the discussion on the origin of ferments that was carried on before the Academy of Sciences in 1871-1872. In the course of that discussion M. Fremy had announced his intention of publishing an extensive Memoir, full of facts, bearing on the subject. The perusal of the promised work gave us much disappointment. Not only were our experiments, and the conclusions which we drew from them, given there, for the most part in a manner which we could not possibly accept, but, moreover, M. Fremy had confined himself to deducing, by the help of his favourite hypothesis, a series of _à priori_ opinions based on half-finished experiments, not one of which, in our opinion, had been brought to the state of demonstration. To tell the truth, his work was the romance of hemi-organism, just as M. Pouchet’s work of an earlier date was the romance of heterogenesis. And yet, what could be clearer than the subject under discussion? We maintain, adducing incontestable experimental evidence in support of our theory, that living, organized ferments spring only from similar organisms likewise endowed with life; and that the germs of these ferments exist in a state of suspension in the air, or on the exterior surface of objects. M. Fremy asserts that these ferments are formed by the force of hemi-organism acting on albuminous substances, in contact with air. We may put the matter more precisely by two examples:—

Wine is produced by a ferment, that is to say, by minute, vegetative cells which multiply by budding. According to us, the germs of these cells abound in autumn on the surface of grapes and the woody parts of their bunches; and the proofs which we have given of this fact are as clear as any evidence can be. According to M. Fremy, the cells of ferment are produced by spontaneous generation, that is to say, by the transformation of nitrogenous substances contained in the juice of the grape, as soon as that juice is brought into contact with air.

Again, blood flows from a vein; it putrefies, and in a very short time swarms with bacteria or vibrios. According to us the germs of these bacteria and vibrios have been introduced by particles of dust floating in the air or derived from the surface of objects, possibly the body of the wounded animal, or the vessels employed, or a variety of other objects. M. Fremy, on the other hand, asserts that these bacteria or vibrios are produced spontaneously, because the albumen, and the fibrin of the blood themselves possess a semi-organization, which causes them, when in contact with air, to change spontaneously into these marvellously active minute beings.

Has M. Fremy given any proof of the truth of his theory? By no manner of means; he confines himself to asserting that things are as he says they are. He is constantly speaking of hemi-organism and its effects, but we do not find his affirmations supported by a single experimental proof. There is, nevertheless, a very simple means of testing the truth of the theory of hemi-organism; and on this point M. Fremy and ourselves are quite at one. This means consists in taking a quantity of grape juice, blood, wine, &c., from the very interior of the organs which contain those liquids, with the necessary precautions to avoid contact with the particles of dust in suspension in the air or spread over objects. According to the hypothesis of M. Fremy, these liquids must of necessity ferment in the presence of pure air. According to us, the very opposite of this must be the case. Here, then, is a crucial experiment of the most decisive kind for determining the merits of the rival theories, a criterion, moreover, which M. Fremy perfectly admits. In 1863, and again in 1872, we published the earliest experiments that were made in accordance with this decisive method. The result was as follows:—The grape juice did not ferment in vessels full of air, air deprived of its particles of dust—that is to say, it did not produce any of the ferments of wine; the blood did not putrefy—that is to say, it yielded neither bacteria nor vibrios; urine did not become ammoniacal—that is to say, it did not give rise to any organism; in a word the origin of life manifested itself in no single instance.

In the presence of arguments so irresistible as these, M. Fremy, throughout the 250 pages of his work, continues to repeat that these results, which, he admits, seem subversive of his theory, are, nevertheless, explicable by the circumstance that the air in our vessels, although pure at first, underwent a sudden chemical change when it came in contact with the blood, or urine, or grape juice; that the oxygen became converted into carbonic acid gas, and that, in consequence, hemi-organism could no longer exercise its force. We are astonished at this assertion, for M. Fremy must be aware that, since 1863, we have given analyses of the air in our vessels after they had remained sterile for several days—for ten, twenty, thirty, or forty days—at the highest atmospheric temperatures, and that oxygen was still present, often even in proportions almost identical with those to be found in atmospheric air.[185] Why has M. Fremy made no allusion to these analyses? This was the chief, the essential point in question. Besides, if M. Fremy had wished to test the truth of his explanation, there was a very simple means of restoring the purity of the air in contact with the liquids open to him; he might have passed through his vessels a slow and continuous current of pure air, day and night. We have done this a hundred times, and we have always found that the sterility of the putrescible or fermentable liquids remained unaffected.

The hemi-organism hypothesis is, therefore, absolutely untenable, and we have no doubt that our learned friend will eventually declare as much before the Academy, since he has more than once publicly expressed his readiness to do so as soon as our demonstrations appear convincing to him. How can he resist the evidence of such facts and proofs? Persistence in such a course can benefit nobody, but it may depreciate the dignity of science in general esteem. It would gratify us extremely to find the rigorous exactness of our studies on this subject acknowledged by M. Fremy, and regarded by that gentleman with the same favour bestowed upon it everywhere abroad. It may be doubted if there exists at the present day a single person beyond the Rhine who believes in the correctness of Liebig’s theory, of which M. Fremy’s hemi-organism is merely a variation. If M. Fremy still hesitates to accept our demonstrations, the observations of Mr. Tyndall may effect his conversion.

The other publication to which we alluded was the work of the celebrated English physicist, John Tyndall. It was read before the Royal Society of London, at a meeting held on January 13, 1876.

The following letter explains how the illustrious successor of Faraday at the Royal Institution came to undertake these researches:—

“London, February 16, 1876.

“Dear Mr. Pasteur,—

“In the course of the last few years a number of works bearing such
titles as ‘The Beginnings of Life’; ‘Evolution and the Origin of
Life,’ &c., have been published in England by a young physician, Dr.
Bastian. The same author has also published a considerable number of
articles in different reviews and journals. The very circumstantial
manner in which he describes his experiments, and the tone of
assurance with which he advances his conclusions, have produced an
immense impression on the English as well as the American public.
But what is more serious still, from a practical point of view, is
the influence that these writings have exercised on the medical
world. He has attacked your works with great vigour, and, although
he has made but slight impression on those who know them thoroughly,
yet he has succeeded in producing a very great and, I may add, a
very pernicious one on others.

“The state of confusion and uncertainty had come to be so great
that, about six months ago, I thought that I should be rendering a
service to science, and at the same time performing an act of
justice to yourself, in submitting the question to a fresh
investigation. Putting into execution an idea which I had
entertained for some six years, the details of which were set forth
in an article in the _British Medical Journal_, which I had the
pleasure of sending you, I have gone over a great deal of the ground
on which Dr. Bastian had taken his stand, and, I believe, refuted
many of the errors by which the public had been misled.

“The change which has taken place since then in the tone of the
English medical journals is quite remarkable, and I am inclined to
think that the general confidence of the public in the exactness of
Dr. Bastian’s experiments has been considerably shaken.

“In taking up these researches again, I have had occasion to refresh
my memory by another perusal of your works; they have revived in me
all the admiration which I experienced when I first read them. It is
my intention now to pursue these researches until I have dissipated
any doubts that may be entertained in respect to the unassailable
exactness of your conclusions.

“For the first time in the history of science, we are justified in
cherishing confidently the hope that, as far as epidemic diseases
are concerned, medicine will soon be delivered from empiricism, and
placed on a real scientific basis; when that great day shall come,
humanity will, in my opinion, recognise the fact that the greatest
part of its gratitude will be due to you.

“Believe me, ever very faithfully yours,

“JOHN TYNDALL.”

We need scarcely say that we read this letter with the liveliest gratification, and were delighted to learn that our studies had received the support of one renowned in the scientific world alike for the rigorous accuracy of his experiments as for the lucid and picturesque clearness of all his writings. The reward as well as the ambition of the man of science consists in earning the approbation of his fellow-workers, or that of those whom he esteems as masters.

Mr. Tyndall has observed this remarkable fact, that in a box, the sides of which are coated with glycerine, and the dimensions of which may be variable and of considerable size, all the particles of dust floating in the air inside fall and adhere to the glycerine in the course of a few days. The air in the case is then as pure as that in our double-necked flasks. Moreover, a transmitted ray of light will tell us the moment when this purity is obtained. Mr. Tyndall has proved, in fact, that to an eye rendered sensitive by remaining in darkness for a little, the course of the ray is visible as long as there are any floating particles of dust capable of reflecting or diffusing light, and that, on the other hand, it becomes quite obscure and invisible to the same eye as soon as the air has deposited all its solid particles. When it has done this, which it will do very quickly in two or three days, if we employ one of the boxes used by Mr. Tyndall—it has been proved that any organic infusions whatever may be preserved in the case without undergoing the least putrefactive change, and without producing bacteria.

On the other hand, bacteria will swarm in similar infusions, after an interval of from two to four days, if the vessels which contain them are exposed to the air by which the cases are surrounded. Mr. Tyndall can drop into his boxes, at any time he wishes, some blood from a vein or an artery of an animal, and show conclusively that such blood will not, under these circumstances, undergo any putrefactive change.

Mr. Tyndall concludes his work with a consideration of the probable application of the results given in his paper to the etiology of contagious diseases. We share his views on this subject entirely, and we are obliged to him for having recalled to mind the following statement from our _Studies on the Silkworm Disease_:—“Man has it in his power to cause parasitic diseases to disappear off the surface of the globe, if, as we firmly believe, the doctrine of spontaneous generation is a chimera.”

THE END.

Footnote 185:

See _Comptes rendus_, vol. lxi., p. 734, 1863.

INDEX.

A

Absorption of gases by air-free liquids, 292
oxygen by blood, 50;
by urine, 50
from solutions by _bacteria_, 295

Acidity, natural, of wine a preservative, 2, and footnote
of beer heated, 20
action on ferments, 35

Acetate of lime from fermentation of tartrate, 288

Acid, sulphuric, facilitating filtration, 250

Acid, carbonic, _v._ carbonic acid

Adaptability of liquids to certain growths, 36, 73, 85
(supposed) of vibrios to aërobian or anaërobian conditions, 309, 310

Aeration, reviving influence of, 138
adoption by brewers of, 253
tardy, of wort in deep vessels, 348
on “coolers,” its importance, 348, 349

Aeration-conditions in ordinary brewing process, 350, 351, 364, 365

Aeration of wort, apparatus for regulating, 352

Aeration, influence on clarification of worts, 381
experiments on its influence on growth, 107, 130

Aërobian, definition, 116
ferment, growth of, 208, 209
ferments, general characteristics, 210;
origin of, 210 (footnote);
cultivation of, 211;
aspects of, 212-217;
distinguishing features of, 218
life in ferments overlooked, 260

“Age,” as applied to a ferment, 169

Age of cells, 246

Aged aspect of exhausted cells, 133, 147

Air, influence on ferment-life, 242
renewal of, in brewers’ yeast, 246, 247
mode of expulsion from growing media, 285
unnecessary to life of _vibrios_, 292
injurious to life of _vibrios_, 304

Air, compressed, and ferment-life, 324
composition unaffected by contact with blood, &c., 398

Albumen-transformation theory of fermentation, 273

Albuminous liquids, growth of yeast in, 265

Alcohol, percentage is heated beer, 20

Alcoholic ferment, minute species of, 71

Alcohol, detection in minute quantity, 78, 79 (footnote)
produced by _penicillium_, 99, and following pages
by _aspergillus glaucus_, 101, and following pages
by _mycoderma vini_, 111, 113
explanation of, 114

Alcoholic fermentation, general explanation of, 114, 115

Alcohol, proportion of, to mucor forming it, 134, and following pages

Alcohol produced by moulds, 258 (footnote)
production of, within fruits, 267

Alcoholic fermentation, restricted meaning, 275 (footnote)
necessary relation with yeast-cells, 275

_Altenaria tenuis_, 157

Ammonia, a test for vegetable organisms (Robin), 312

Ammoniacal urine, 45, 46

Anaërobian, definition, 116
growth of yeast, 239, and following pages
precautions to be observed in, 248
life of fruit-cells, 272
growth of _vibrios_, 302

Animal or vegetable nature of organisms, 312, and following pages

Anti-ferments, 45

Apparatus for sterilizing liquids, 27
for producing pure beer, 340, &c.
for pure pitching, 344
for pure aeration, 352
for cooling beer with regulated supply of pure air, 388, 389

Appert’s experiment, 62

Aroma of beer destroyed by excess of air, 353

Asbestos, useful plug, 27, and footnote, 30

Ascospores of yeast, 150 (footnote)

Aspect of yeast variable, 37

_Aspergillus glaucus_, functioning as ferment, 101, and following pages
different aspects of, 105

Atmospheric germs, 6, 26, 38
variety of, 39, 76, 87 (footnote)

_Autonomy_ of organisms, 84 (footnote)

B

Bacteria, 35, 36;
medium for growth of, 294;
absorption of air from solutions by, 295

Bacteria and butyric vibrios, how related, 296
influence of oxygen upon, 305

Bail mentioned, 92, 93, 127

Balling saccharometer explained, 363 (footnote)

Barley-wine, 1 (footnote), 230

Barley decoctions, experiments on development of ferments in, (Fremy)
273 (footnote)

Bary, De, mentioned, 92;
on relations of yeast to other organisms, 180, 181

Bastian’s experiments, 403

Baudelot refrigerator, 387 (footnote)

Bavarian beer, 10

Béchamp’s _microzyma_ theory, 121
influence of air on fermentation, 178 (footnote)

Beer, definition, 1;
difference between it and wine, 1
changeable nature of: effects upon brewing purposes, 2, 3
two kinds only, “high” and “low:” difference, 7
samples of bottled, examined, 222
general precautions for pure manufacture of, 338
improved apparatus for commercial production, 340, and following
pages

Beet root preservation in pits, 269 (footnote)

Berkeley mentioned, 92

Bellamy’s researches on fermentation in fruits, 270

Berard on fermentation of fruits, 270, 271

Berthelot’s mode of isolating inverting constituent of yeast, 322
(footnote)

Bert, action of compressed air on ferments, 324

Birds, experiment upon, described, 309

Bistournage, 43 (footnote)

Bisulphite of lime used by bottlers, 15

Blood, study of sterilized, 49, 50

Blood-crystals, 50 (footnote)

Boiling sterilizes liquids, 34

Bottling needle, 372 (footnote)

Bottled beer, treatment of, 16

_Bouche_ influenced by presence of oxygen, 387

Bouchardat, 323

Brefeld, strictures on Pasteur’s theory criticised, 280
convinced of truth of Pasteur’s theory, 315, 316

Breweries, statistics of, 10

Brewing, change in processes of, 7
practices largely empirical, 222

Brewing processes under conditions of purity, 390

Budding, rate of, experiment on, 145
process of, 146

Buffon’s hypothesis mentioned, 121

Bulbs, glass, for study of growths, 156 (footnote)
for vibrios, 298

Bunsen, tables of solubility of oxygen in water, 360

Butyric vibrios in must, 65;
in wort, 70

Butyric acid from fermentation of lactates, 297
not a suitable food for vibrios, why?, 301 (footnote)

Butyric fermentations yield variable products, 308

C

Cagniard Latour, on cause of fermentation, 60

Calmettes, M., 369, 371;
experiments on the curve of cooling of wort, 377, 378

Carbolic acid for purifying yeasts, 232

Carbonate of lime crystals formed in fermentation of lactate, 294

Carbonic acid, influence on preservation and fermentation of fruits,
268
evolution from fermentation of tartrate of lime by vibrios, 287
amount of evolution, 288
mode of collection of, 288
influence on bacteria, 305 (footnote)

Caseous ferment, occurrence, 200;
aspect, 201;
endurance of heat, 203 (footnote);
meaning of title, 202;
origin of in brewers’ high yeast, 203, 204;
origin of in English pale ale, 204, 224;
aërobian form of, 215

Cells, power of endurance, 134
aspect of dead, 139 (footnote)

Cells, glass, for study of growths, 155 (footnote)

Cells, probable function in elaborating proteic matter, 335

Cellulose, not soluble in ammonia (Robin), 312

Change of yeast, usual remedy for disease, 22

Chauveau on castration, 43

Circumstances modifying nature of germs present in atmosphere, 73, 87
(footnote)

_Cladosporium_, 55 (footnote)

Clarification of liquids by fungi, 66 (footnote)
of wort, 381, and following pages
of a wort and its beer not always correlated, 382, 383

Cohn’s medium for growth of vibrios, 294 (footnote)

Colour darkened by oxidation in pure liquids, 57

Coloration of vibrio-fermented liquors, 291

Colpoda, 39, 40

Composition of medium, influence on life, 296

Conidia, definition, 137

Conditions affecting the ferment character of cells, 266

Consumption of beer in France, statistics, 17 (footnote)

Contagion and ferments, 41, and following pages

Continuity, non-, of germs in air, 62

Continuous vital activity of cells, 278

Contact-action, theory of, 326

“Coolers,” importance in aeration of wort, 348, 349
influence on worts, 364

Cooling of wort must be rapid in ordinary brewing, 2
artificial of “low” beers, 12

Cooling of wort in presence of carbonic acid, 342;
difficulties of the process, 346, and following pages

Corpuscles on grapes and stalks, 54

Corpuscles refractive in bodies of vibrios, 300, _v._ also cysts

Correlation of special germs with special fruits, 61
of special ferment and fermentation product, 277

Cotze and Feltz, 43

Crushers for the vintage, 268 (footnote)

Cream of tartar, _v._ tartrate

Cultivation of yeast under conditions of purity, 29-32
of pure penicillium, mode of, 88, and following pages
of aërobian ferments, 211, and following pages

Cysts of vibrios, 306, 307

D

Davainne, on splenic fever, &c., 42

Daughter-cells, 146

Dead cells, aspect of, 139 (footnote)

Declat’s treatment of infectious diseases, 44

_Dematium_, 167;
resemblance to _Saccharomyces pastorianus_, 179, 180, 181, 214
resemblance to “caseous” yeast, 201

Degrees, Balling, _v._ Balling

Deposits, amorphous, of wort, 6, 193, 385, and footnote

Deterioration of beer correlated with presence of foreign organisms,
26, 32

Differential vitality, a means of separating ferments, 226

Difficulty of experiments on growths, 63, 85

Disease-ferments, what they are, why so called, 4
classification and account of, 5, 6
origin of, 6
inactive at low temperatures, 14
often found only in deposits, 24
not everywhere in atmosphere, 31

Disease-germs usually latent, 220
development in bottled beer, 222

Diseases of wort and beer, meaning of, 19
mode of proving the cause of, 19, 20

Diseased beer always result of disease ferments, 26

Distribution of germs limited, 61

Division, fissiparous, of vibrios, 299

Dried yeast, 81

Dryness decreases sensitiveness of moulds to heat, 35

Dumas, distinction between organized and unorganized ferments, 323

Dust, atmospheric, contains disease-germs, 6, 26
on fruits, experiments with, 153, and following pages
when fertile, 157, and following pages

Dutch yeast, 200

Duval, Jules, experiments on transformation of ferments illusory, 37

E

_Efflorescence_ of fermented liquors, 108, 117

Egg-albumen, experiments on, 51

Egypt, beer first brewed in, 17

Empiricism in ordinary brewing, 222

Energy stored by cells, 133, 134

Endogenous sporulation of yeast, 150 (footnote), 172

English beers all “high,” 7
temperatures and yeast employed, 8 (footnote)
breweries, usages of, 8 (footnote), 14

Errors, causes of, _v._ experimental errors

Equations of fermentations variable, 276, 277

Examination of deposits, mode of, 21 (footnote)

Exhaustion, definition of, 171 (footnote)

Exhausted vibrios, 290

Experimental errors, 63, 85, 92
avoided by use of double-necked flasks, 120

Experiments, exactness of Pasteur’s, 95 (footnote)
to prove connection between quality of ferment and quality of beer,
26, and following pages
on living fluids, 47, and following pages
comparative, on pure must and must with corpuscles boiled and
unboiled, 54, and following pages
by Gay-Lussac on must, 62, 63
by Pasteur after Gay-Lussac, 64
on distribution of ferments, 65, and following pages
on distribution of fungus-spores, 68
in wide shallow dishes, 69, and following pages
comparative on germs in air, 72, and following pages
with non-fermentative species of _torula_, 78
on spontaneous impregnations, 65, 66, 69, 73, 79, 87 (footnote)
on spontaneous fermentation, 184
on dried yeast, 81, and following pages
on influence of aeration on growths, 107
on aeration and its absence, 130, and following pages
on function of oxygen on ferment-life, 238, and following pages
on the capacity of yeast for oxygen, 255
on influence of carbonic acid on fruits, 268
on growth of vibrios apart from air, 285
on fermentation of lactate of lime apart from air, 292, and following
pages
on influence of air on vibrio-life, 303, 304
on influence of air on bacterium-life, 305
on gradual adaptability of organisms to adverse life-conditions, 309
on influence of air on fermentation, 349
on solubility-coefficients of wort for oxygen, 361-3
of brewers’ worts, 366, and following pages
on combination of oxygen with worts, 371, and following pages
on the rapidity of the combination, 376
on amount of combination, 379
on non-transformation of _mycoderma vini_, 110, and following pages,
113 (footnote)
of _mycoderma aceti_, 124, and following pages
of _mucor racemosus_, 128, and following pages
on non-transformation of yeast into penicillium, 333-335
on cultivating pure _penicillium_, 88, and following pages
on its transformation into yeast, 91
transformation, Trécul’s, details of, 98
with submerged _aspergillus_, 101, and following pages
_penicillium_, 99
in disproof of the _hemi-organism_ theory, 273 (footnote)
on growth of mixed moulds, 112
on purification of mixed ferments, 226, and following pages
on growth of _mucor mucedo_, 140, 141
on proportion between weights of mucor and alcohol formed, 134, and
following pages
on the anaërobian cultivation of yeast, 239, and following pages
on variation of proportion of sugar used to yeast formed, 249
on growth of yeast in sugar solutions, 318, and following pages,
331-333
on dust on fruits, 153, and following pages
on seasonal influences on fertility of dust-germs, 157, and following
pages
on exhaustion of yeast, 169, and following pages
of “high” yeast, 189, 190
on revival of yeast, 207, 208
on cultivation of aërobian ferment, 211, and following pages
on gradual _senescence_ of yeast, 245
on production of a pure beer, 338, and following pages
on clarification of worts and beers, 382, and following pages
comparative, on the qualities of beers brewed by different processes,
391
on rate of budding, 145

Exportation of “high” beers unsatisfactory, 16

F

Ferment, _v._ also yeast

Ferments of disease, _v._ disease-ferments

Ferments, special, 14, 15

Ferments and animal diseases, 41, and following pages
butyric, lactic, alcoholic, 72
moulds functioning as, 100, 101, and following pages, 111, 113, 129,
133
general character of a, 115
of grape, varieties, origin, 150, and following pages
alcoholic, summary of, 196
intermixture of, 224, 225
mode of separation of mixed, 226 and following pages
succession of, in must, 227
exceptional vital processes of, 236, 237

Ferment power in relation to time discussed, 252
character, how related to heat, 270
and fermentation correlated, 277
a chemical substance existing in cells (Traube), 283 (footnote)
of tartrate of lime, 290

Ferments, two classes, distinctive characteristics, 323

Fermentation, rapid, inexpedient, 3
spontaneous, in case of must, 4
“top” and “bottom,” _v._ “high” and “low”
masked by moulds in shallow vessels, 75 (footnote)
by _penicillium_ (Tréoul) 94
by _mycoderma vini_, 111, 113
by _mucor racemosus_, 129, 139
alcoholic, general explanation of, 114, 115
conditions of, in sweetened mineral liquids, 211
without air, 242
with and without air, results compared, 243, 244
a cell-life without air, 259
a general phenomenon, 266, 267
of fruits not truly “alcoholic,” 276
not definable, according to Brefeld, as life without air, 280
of lactate of lime, 294

Fermentative energy, 252
character dependent on conditions, 266

Filamentous tissue (Turpin), 123

Fitz on fermentation, 142

Fissiparous division of vibrios, 299

Flask sterilizing, 27, 29

Flasks with double necks, advantage of, 120

Fluid, Raulin’s, 88 (footnote)

Flavour dependent on ferment species, 230

Foreign organisms correlated with unsound beer, 26, 32
greatly promoted by adaptability of liquids, 36

Formula for solubility-coefficient of any wort for oxygen, 364

Fremy’s statement of _hemi-organism_, 52
answer to Pasteur’s facts, 58
explanation of vintage fermentation, 272
“organic impulse,” 325
latest assertions, 396-399

Fruits, ferment organisms on surface of, 153, and following pages
internal fermentation of, 267, and following pages
yeast cells not present within, 267 (footnote)
influence of carbonic acid gas on preservation of, 268
respiratory processes of, according to Bérard, 270
fermentation within, Lechartier and Bellamy, 270
crushed and uncrushed, fermentation of, 274

Fruit-cells, anaërobian life of, 272

Fungi, wide distribution of spores, 68
absorption of oxygen by, 257
production of alcohol by, 258 (footnote)

Fungoid manner of growth of well-aerated yeast, 251

G

Galland’s claims of priority, 338 (footnote)

Gay-Lussac’s experiments on grape-juice, 59, 60

Gayon’s experiments on egg-albumen, 51

“Gathered,” 367 (footnote)

Generation, theories of, contrasted, 397

Germs of ferments in air, &c., 6, 26, 38
brought by other matters, 38
absent from fruits, when? 58, 59, 157, and following pages
not universally distributed, 61, 63, 181 (footnote)
distribution experiments, 65, and following pages, 87 (footnote)
and their correlated fruits, 61
of disease latent, 220

_Germ_, use of term by Pasteur, 313

Germ theory of disease discussed, 46, 47

Globuline tissue (Turpin), 123

Globulines, punctiform, 121, and following pages

Globules, 275 (footnote)

Glycerine, fermentation of, by vibrios, 306, 307

Gosselin, M., report, 44
and Robin on ammoniacal urine, 45

Gramme, value in grains, 135 (footnote)

Granules in wort, explanation of, 95

Graham’s, Dr., criticisms of Pasteur, 13 (footnote), 196 (footnote)

Graham, Dr., on aspect of bottom yeast, 194 (footnote)

Grape juice, experiments on, 57, 59

Grape-ferments, _v._ ferments

Grapes, do they contain cells of yeast? 267

Greasiness of _mycoderma vini_, 80, and footnote

H

Hallier mentioned, 92

Hard water, influence on aspect of yeast, 194 (footnote)

_Head_ of vibrio, 292

Heating sufficient as preventing deterioration of liquids, 20
influence on beer, 20

Heat, production of, its relation to ferment-power, 270

_Hemi-organism_, chimerical, 53, 162, 399, 273 (footnote)
latest assertions by Fremy on subject of, 396-399
theory of vintage-fermentation, 272, 273

Heterogenesis, facts against, 51

“High” fermentation, meaning of, 8, 9
beers, disadvantages of, 12, 13
ferment, aspect of, 188, 189
characteristics of, summary, 191
ferment (new), occurrence, 198
aspect and characteristics of, 199
aërobian form of, 216

High yeast, aërobian form, aspect of, 214

Hoffmann, H., transformation of ferment, 92, 93

Hop-oil as a beer-antiseptic, 16, and footnote

Hopping influence on growths _quâ_ temperature, 96

Hot countries, absence of breweries in 16

Hydrogen from vibrionic life, 300
occasional absence in butyric fermentations, 308

Hydrosulphite of soda, composition, use in determinations of oxygen,
355, and footnote
preparation of _saturated_ solution, 357 (footnote)
alterability of solutions of, 356
improved method of M. Raulin, 356, and following pages

I

Ice, quantities consumed in “low” breweries, 11

Illusions as to absence of foreign organisms, 36, 85, 92

Impregnations, spontaneous, 65, 66, 69, 73, 79

Impregnation, mode of (_penicillium glaucum_), 86

Impurity of ferments, source of experimental errors, 37
of yeast masked for a time, 220

Increase of yeast disproportionate to sugar used, 237

Infusions, nature of organisms in, 39

Infusoria, 35

Insoluble substances in wort, 386

Inverting constituent of yeast, 321, and footnote

Isolation of ferment, 77

L

Lactic ferments, 5, 36
transformation from and into other ferments (Duval), 37

Lactate of lime, fermentation of, 292

Lechartier and Bellamy, researches on fermentation in fruits, 270

Leptothrix, 36

Liebig’s views of fermentation, 317, and following pages
on fermentation of malate of lime, 321
definition of a ferment, 324
modified theory, 326;
answer to, by Pasteur, 326, 327
neglect of microscopical observations, 329, 330

Lime, bisulphite, use of, by bottlers, 15
carbonate sterilized, use of in growths, 126
dextro-tartrate, 284
acetate and metacetate, 288
lactate, fermentation of, 292

Lister’s, Prof., letter on germ-theory, 43

London breweries, usages of, 8 (footnote)
Pasteur’s visit to, 22-24

“Low” fermentation, meaning of, 9, 10;
advantages, 12
beer breweries, statistics of, 10
properties of, according to Dr. Graham, 13
yeast and “high” yeast distinct, 192, 193
yeast, aspect of, 193;
characteristics, 195
aërobian form of, 215

Low temperatures prejudicial to disease-ferments, 14

M

Malignant pustule, 42

Mashings, 3

Medium, mineral, for growing lactic vibrios, 293, 297 (footnote)
Cohn’s formula, 294 (footnote)
for growth of bacteria, 294

Medium, composition of, influence on life, 296

Microscopical study of yeast important, 23
formerly neglected in English breweries, 22-24

Microscopical examination of vibrios, 298, 299

Microzyma, 121;
source of _mycoderma aceti_ according to Béchamp, 124

Milk, temperature of sterilization of, 34

Milk-sugar, growth of yeast in, 265

_Mother of vinegar_, _v._ mycoderma aceti

Moulds thrive in acid liquors, 36
functioning as ferments, 100, 101, and following pages, 111, 113,
129, 133
growth of, and production of alcohol, 257, 258 (footnote)
suggested employment of, industrially, 261

Mucedines, 36, 40

_Mucor mucedo_ and _racemosus_ on must, 66

_Mucor racemosus_, different aspects of, 105
pure growth of, 128, and following pages

Mucor normal, growth of, 132
weight of to alcohol formed, 134, and following pages
morphology of abnormal growth, 137

_Mucor mucedo_ distinguished from _racemosus_, 140
growth in double-necked flasks, 140, 141

Müntz, 323

Must, fermentation of, always regular, 3
pure fermentation of, 54, and following pages
succession of ferments in, 227, 228

_Mycelium_ and _mycoderma vini_ on wine, 56, 65

Mycoderma in wort experiments, 70

_Mycoderma vini_, arborescent form of, 77
growth of pure, experiments on, 110, and following pages, 120
growth with _penicillium_, 112
with _mucor_, 112
endogenous sporulation, 151 (footnote)

_Mycoderma aceti_ transformations (Béchamp), 124
pure growth of, 124, and following pages

N

_Nageurs_ used in low fermentation, 9

Nature of liquids, influence on growths, 36, 73, 85

Natural liquids for pure growths, use of, 40, 41
experiments on, 47, and following pages

Neutrality, conditions of, as affecting sterilization of liquids, 34;
explanation of fact, 35

Neutralization of acidity in pure growths, mode of, 126

New high ferment, _v._ high

New process of brewing, 391-393

Nitrogenous soluble parts of yeast, 319, 320

Nomenclature used by Pasteur purposely vague, 314

Normal growth of mucor, 132

O

Organic substances, have they any tendency to become organized? 33

Organic liquids sterilized by boiling, 34

Organizable globulines (Turpin), 123

Organisms and animal diseases, 42

_Ouillage_, 2

Oxidation of germ-free liquids, 57
processes of fungi, 261, and footnote
of wort, excessive, injurious, 353, 354

Oxygen absorbed by blood, 50
by urine, 50
and fermentation, according to Gay-Lussac, 60
store-energy imparted to cells by, 134
no influence upon fermentation, (Béchamp), 178 (footnote)
function in fermentation, experiments on, 238, and following pages
influence on fermentation (Schützenberger and Pasteur), 253, 254
amount absorbable by yeast, 255
deficiency of, function in fermentation, 259
influence on products, 100, 108, 113
influence on morphology of moulds and ferments, 105, 106, 133, 137,
262
necessity of, to growth of yeast discussed, 280
unnecessary and adverse to vibrionic life, 284, and following pages
necessary to bacterial life, 305
removal from solutions by bacteria, 295
growth of vibrios apart from, 302
compressed, influence on ferment life, 324
determination of, in worts (Schützenberger), 355, and following pages
solubility-coefficients in water (Bunsen), 360
usual amounts in solution in brewers’ worts, 366, 367
changes in amounts during brewing processes, 369, 370
combination of, with hopped wort, 371, and following pages
experiments on rapidity of combination, 376
on amount of, under brewing conditions, 379
in combination with wort not available for yeast, 380, 381
clarification of wort by, 385

P

Palate-fulness definition, 354, and footnote
impaired by oxidation, 354

Parasites and their germs, 40
influence on animal diseases, 41

Pasteur’s repetition of Trécul’s experiments, 98, 99
subject of his inquiries stated, 311
experiments, exactness of, 95 (footnote)

Pasteurization, meaning and use, 15 (footnote)

Patches of froth in growth of pure yeast, 31

_Penicillium glaucum_ on must, 66
growth of pure, 86, and following pages
precaution, 89
transformed into ferment (Trécul), 94
spores, varieties of, 97
production of alcohol by, 99, and following pages
transformation into mycoderma, 109

Phenol for purifying yeasts, 232

Pitching, mode of, for pure beer, 342, and following pages
flasks, 344
peculiar in London breweries, explanation, 350, 351

Plaster of Paris and yeast powder, 81, and following pages

_Ploussard_ grapes, experiments on, 161

Polymorphism of organisms, 84 (footnote), also _v._ transformation

Precautions for pure fermentation of must, 64
brewers’, to check disease-germs, 220, and following pages
for pure anaërobian growth of yeast, 248

Preservation of yeast, 207

Preoccupation of liquids by organisms, 36, 109, 220

Products of fermentation variable, 276, 277

Price of beer as affected by losses from disease, 24

Proliferous pellicles, 121

Proportions of alcoholic products variable, 276, 277

Proportions of products diagnostic of the fermentation, 279

Proteic matter elaborated by cells, 335

“Pulling up,” 343

Pure growth of yeast, precautions for, 29-32
growths in natural liquids, 40, 41
wort and ferment, advantages of, 391-393

Purification of mixed ferments, 226, and following pages
practical methods, growth in sweetened water, 230
shallow basins, 231
in acid and alcoholic liquids, 231
with aid of carbolic acid, 232

Putrid wort, ferments of, 5

Putrefaction prevented by use of sterilizing flask, 27
of yeast, cause of, 221
of tartrate of lime, 291

Q

Qualities of “high” and “low” beers, 12, 13, 19, 196

Quality of beer dependent on kind of ferment, 26, and following pages

R

Racking, 222
precautions necessary in, 351

Raulin’s fluid, 88 (footnote)
improvement on Schützenberger’s oxygen process, 356, and following
pages
experiments on solubility of oxygen in worts, 361-363

Rayer on splenic fever, &c., 42

Reducing action of vibrios, 291

Rees, Dr., 150 (footnote)

Refrigerator, Baudelot’s, 387 (footnote)

Revival of mould-cells by aeration, 130, 131 (footnote), 138

Revival of starved yeast, 148, 208
vibrios, 301, 302

Ripening of fruits, 270, 271

Robin, Ch., mentioned, 93;
strictures on Pasteur, 310, 311
recantation of views on fermentation, 314

S

_Saccharomyces apiculatus_, 71, and footnote, 150
_exiguus_, 185,
_ellipsoideus_, 165
_pastorianus_ 151;
mode of growth of, 167
two aspects, globular and filamentous, 168, 169
exhaustion and revival of, aspects, 172, and following pages
occurrence as impurity in most ferments, 225
most suitable for growth experiments in sugar solutions, 332

_Saccharomyces pastorianus_, _ellipsoideus_, _apiculatus_ in must, 227,
and following pages

_Sang de rate_, 43

Schützenberger on budding of yeast, 146, and footnote

Schützenberger’s strictures on Pasteur’s views answered, 252, and
following pages
process for determining oxygen in solutions, 355

Seasons, influence on success in brewing, 25
at which germs are absent on fruits, 58, 59

Secondary fermentation in English beers, 224

_Senescence_ of yeast cells, 208
gradual of yeast cells, experiments on, 245

Shallow basins for purification of yeasts, 231

Sodium hydrosulphite, _v._ hydrosulphite

Solubility-coefficients of oxygen in water (Bunsen), 360
in worts (Raulin), 361-363

Sour beer, ferments of, 5

Soundness of beer always dependent on purity of yeast, 26, 32

Specialization of ferment-variations, 197

Specimens, necessary precautions for taking, 126 (footnote)

Splenic fever, 42

Spontaneous fermentation used in must, not in beer, 4
fermentation or putrefaction prevented by use of sterilizing flask,
28
ferment, definition of, 182;
experiment on, 184
generation, facts against, 51, 52, 57
supported by experimental errors, 62, 63
(Trécul’s theory of), 94, 95
impregnations, 65, 66, 69, 73, 79
use in isolating ferments, 77

Spores on grapes, gooseberries, &c., 54
of fungi widely distributed, 68

Statistics of breweries, 10
of French beer consumption, 17 (footnote)

Starved yeast, appearance of, 148

Stability of sterilized liquids, 286

_Stemphylium_ spores, 55 (footnote)

Sterilizing apparatus, 27, 29, 285
flask, 28

Sterilization-temperature of various liquids, 34

Stock beer, 223

Store beer, must be surrounded by ice, 16

Straw wine, peculiar fermentation of, 166

_Strength_, Pasteur’s use of word, 354
saving by the new process, 394

Submerged _penicillium_, 99
_aspergillus_, 101, and following pages
_mycoderma_, 111, 113, and following pages
_mucor_, 129, and following pages, 133

Submerging growths, precautions for, 91 (footnote)

Succession of transformations (Trécul’s scheme), 93, 94

Sugar decomposition by submerged cells, 114
different modes of, by different cells, 115
decomposed disproportionate to yeast formed, 237, and following pages
variation of disproportion in different cases, 249
amount decomposed in a given time, as an index of fermentative energy
(Schützenberger’s views), 252
solutions pure with mineral salts, growth of yeast in, 317, and
following pages
denial of the fact by Liebig and reply by Pasteur, 328, 329

Surface growth of yeast in pure culture, 31

Sweetened water for exhausting yeast, 169, 170, 190
for purification of yeasts, 230

T

Tartrate-acid of potash for purifying yeasts, 231
-dextro of lime, fermentation of, 284, and following pages
products of, 288
ferment of, 290

Temperatures in use in London breweries, 8 (footnote)
high, prejudicial to quality of “low” beer, 19
at which disease-ferments perish, 20;
differs in different liquids, 34, 96
influence on fermentation, 129

Temperatures suitable for “high” or “low” yeasts respectively, 192
influence of on mixed “high” and “caseous” yeasts, 203
for observing active vibrios, 299

Theories of generation opposite stated, 397

Tieghem, Van, on ammoniacal urine, 45

Torula, sense in which used, 73 (footnote)
varieties of, 77
non-fermentative species, 78

Transformation of ferments, according to Duval, 37
of non-fermentative to fermentative impracticable, 80
of _penicillium_ into yeast impracticable, 91
of ferment into moulds (Hoffmann), 92
series, Trécul’s scheme of, 93, 94
of _penicillium_ to _mycoderma_ (Ch. Robin), 109 (footnote)
of _mycoderma vini_ refuted, 113 (footnote)
Turpin’s system of, 122, and following pages
of _mycoderma aceti_ (Béchamp), 124
historical account of views on, 128 (footnote)
of _mucor_ (Bail), 127
of filamentous into globular yeast, 169
of yeast into _penicillium_, &c., impracticable, 333-335
mutual of low and high yeast, discussed, 192, 193
of “high” yeast into “caseous” ferment illusory, 203
of albumen, theory of the vintage, 272, 273
theory disproved generally, 273 (footnote)

Traube, Dr., on ammoniacal urine, 46
researches on fermentation, 282
theory of fermentation, 283 (footnote)

Trécul and Fremy, _v._ Fremy

Trécul’s theory of successive transformations, 93, 94
details of transformation experiments, 98
theory refuted, 99

_Trousseau_ grapes, experiments on, 162

“Turned” beer, ferments of, 5;
filaments of, 23

“Turning out,” 367 (footnote)

Turpin, M., mentioned, 92

Turpin’s system of transformations, 122, and following pages, 113
(footnote)

Tyndall, letter to Pasteur, 399-401

U

Unsoundness of beer correlated with disease-organisms, 26, 32

Urea-ferment, the transformation of (Duval), 37

Urine, ammoniacal, 45, 46

Urine, sterilized, study of, 49, 50

V

Variability of fermentation products, 277

Variations of ferment strengthened and established, 197

Varieties of yeast, 149, and following pages

Vaureal, De, budding of yeast, 146 (footnote)

Vegetable distinguished from animal organisms by ammonia (Robin), 312

Vesicular tissue (Turpin), 123

Vibrio, 36;
butyric, 65, 70
also an example of anäerobian life, 282, 284
active and exhausted, 290
reducing action of, 291

Vibrionic ferment of tartrate of lime, 290

Vibrios, _head_ of, 292;
supposed reproductive corpuscles, 306
growth of, in lactate media, 293
medium for growth of, according to Cohn, 294 (footnote)
not genetically related to bacteria, 296
of butyric fermentation, description of, 298, 300
mode of examining microscopically, 298
fissiparous division of, 299
measurements of, 300
cannot live on butyrates, 301 (footnote)
revival of, 301, 302;
anaërobian growth of, 302
life of, destroyed by oxygen, 303, 304

Vigour of ordinary brewer’s yeast, 246

_Vin de paille_, 166

Vinegar, temperature at which it is sterilized, 34

Vinous flavour in stock beer, 224

Vintage, varied conditions of, 268 (footnote)
fermentation, theory of, according to Fremy, 272, and following pages

Viscous wort, ferments of, 5

Visit to London brewery by Pasteur, 22-24

Vital processes of ferment exceptional, 237
activity of yeast apart from air, 259
potential in cells, 278

Vitiation of experiments, causes of, 63, 85, 92

W

Wad-dressing, antiseptic, 44

Water, hard, influence on aspect of yeast, 194 (footnote)

Weights of _mucor_ and alcohol, proportion of, 134, and following pages

Weight of yeast grown, what due to, 257 (footnote)

Wide dishes, experiments on fermentation in, 69, 70
favourable to mould developments, 75 (footnote)

Wine, less liable to deteriorate than beer, 2
temperature of sterilization, 34

Wort, definition, 2;
cooling of, 3, 4
temperature of sterilization, 34
solubility of oxygen in, 361, and following pages
formula for solubility in any wort, 364

Worts, brewers’, usual amounts of oxygen in solution, 366, 367
experiments on amounts, 379

Wort, hopped, its affinity for oxygen, 371, and following pages
mode of transmitting it free of oxygen, 371, 372
insoluble substances in, 386

Y

Yeast, _v._ also ferment, germs, torulæ nature and properties of, 143,
and following pages
starved and well-nourished, appearances contrasted, 147, 148
varieties of, 149, and following pages
commercial origin of, where? 187
relations to other organisms, 180, 181
commercial mixtures, 224, 225
practical purification of, 230-233
impurities in masked for a time, 220
exceptional characteristics of, 237
growth of in sterilizing flasks, 29-32
not transformable into any other organism, 37
aspect may change under modified circumstances, 37
non-transformation of _mycoderma vini_ into, 120
_mucor_ into, 132
non-fermentative species of, 79, 80, 206, 207
“high,” characteristic aspect of, 188-192
well aerated, fungoid mode of growth, 251
anaërobian growth, cause of fermentation, 259
growth of, in solutions of sugar, 318, and following pages
growth in relation to proportion of sugar used, 237, and following
pages
difficult propagation in saccharine mineral media, 329, 330
growth of, without producing alcohol, 265
capacity of absorbing oxygen, 255
necessity of oxygen for its growth discussed, 280
incapable of using oxygen in combination in worts, 380, 381
soluble nitrogenous part of, 320, 321, 79 (footnote)
dried into dust still active, 81, and following pages
does not perish at temperatures at which disease-ferments do, 20
sudden inactivity of, cause and cure, 347 (footnote)
change of, a trade custom, 22
reason of addition of yeast to wort, 3
proportion commonly added, 3
reason of the large proportion used, 343.

Yeast-cells abundant in brewing laboratories, 75
gradual senescence of, 245

Yeast-cells, mode of examining fruits for, 267 (footnote)
necessary relation to “alcoholic fermentation,” 275

Yeast-water, definition, 79 (footnote)
exhaustion of yeast by, 171
use of in pure growths (_penicillium_), 88

“Youth” of cells, 246

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● Transcriber’s Notes:
○ Missing or obscured punctuation was silently corrected.
○ Inconsistent spelling and hyphenation were made consistent only
when a predominant form was found in this book.
○ Text that was in italics is enclosed by underscores (_italics_).
○ Text that was in bold face is enclosed by equals signs (=bold=).
○ Footnotes have been moved to follow the chapters in which they are
referenced.
○ Subscripts are transcribed by an underscore and a value enclosed
in braces, such as O_{2}. Superscripts are transcribed by an
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End of Project Gutenberg's Studies on Fermentation, by Louis Pasteur