Produced by Peter Vachuska, Turgut Dincer, Chuck Greif and
the Online Distributed Proofreading Team at
https://www.pgdp.net
+---------------------------------------------------------+
| Transcriber's note: |
| |
| Words in bold characters are enclosed within "+" signs. |
| The list of Putnam Science Series has been moved to the |
| advertisement section at the end of the book. The UTF-8 |
| version of the text file will require a Unicode capable |
| text reader to display a few Greek characters and "oe" |
| ligatures which occur in the book. |
+---------------------------------------------------------+
[Illustration: THE OLDEST WOMAN IN THE WORLD AND HER SON
Baba Vasilka is 126 years old, and her son Tudor is 101.
They are peasants, and have lived all their lives in a
little village in Bulgaria. They are typical examples of
people who live to a great age by the use of soured milk,
as it has been their principal food all their lives.]
The
Bacillus of Long Life
A Manual of the Preparation and Souring of Milk for
Dietary Purposes, Together with an Historical
Account of the Use of Fermented Milks, from
the Earliest Times to the Present Day,
and Their Wonderful Effect in the
Prolonging of Human Existence
By
Loudon M. Douglas, F.R.S.E.
_With 62 Illustrations_
G. P. Putnam's Sons
New York and London
The Knickerbocker Press
1911
_Revised Edition_
COPYRIGHT, 1911
BY
G. P. PUTNAM'S SONS
The Knickerbocker Press, New York
PREFACE
This book has been designed with a view to meet an extensive demand for
definite data on the subject of Soured Milks. The author has had this
matter brought before him, times without number, by those inquiring for
authentic information on the subject, and he has therefore considered it
desirable to gather together such information as is available in
connection with ancient and modern practice. He has endeavoured to
present this to the reader in concise form.
The author is indebted to many friends for their assistance in getting
the book together, and would specially mention Dr. H. B. Hutchinson,
Bacteriologist, Rothamsted Experimental Station, for assistance in
connection with the bacteriology of fermented milks; Mr. Thomas Douglas,
of Wimbledon, who has assisted with the chemistry of the subject; Mr. S.
Javrilovitch, of Belgrade, Servia, for local information and
illustrations; Dr. Otokar Laxa, Bacteriologist, of Prague, Bohemia, for
general assistance; the editor of _Bacteriotherapy_, New York, U.S.A.,
for the use of the group of illustrations 30-44; the publishers of the
_Centralblatt für Bakteriologie_, Jena, for the group of illustrations
14-29; and many others, some of whom are referred to in the text.
CONTENTS
CHAPTER PAGE
I.--INTRODUCTORY--HISTORICAL 1
II.--FERMENTED MILKS 15
III.--THE CHEMISTRY OF MILK 47
IV.--HANDLING OF MILK 68
V.--THE BACTERIOLOGY OF FERMENTED OR SOURED MILK 84
VI.--THE PREPARATION OF SOURED MILK IN THE HOUSE 125
VII.--THE PREPARATION OF SOURED MILK IN THE DAIRY 139
VIII.--SOURED MILK IN HEALTH AND DISEASE 151
INDEX 165
ILLUSTRATIONS
FIG. PAGE
THE OLDEST WOMAN IN THE WORLD AND HER SON _Frontispiece_
THE PASS OF BUKOVA 2
KABYLES SOURING MILK 4
THE HANDLING OF MILK IN THE PYRENEES 8
THE CONSTITUENTS OF MILK 48
1.--MICRO-PHOTOGRAPH OF A DROP OF WHOLE MILK 58
2.--MICRO-PHOTOGRAPH OF SEPARATED MILK 58
3.--MICRO-PHOTOGRAPH OF CREAM 58
4.--PHOTOGRAPH OF TWO PETRI DISHES, WHICH HAVE BEEN
INOCULATED WITH ORDINARY MILK 60
5.--THE CREAMOMETER 62
6.--TESTING-GLASS FOR EXTRANEOUS MATTER IN MILK 62
7.--LACTOMETER AND TEST-GLASS 64
8.--PASTEURISER 78
9.--CONTINUOUS APPARATUS FOR THE PRODUCTION OF LARGE
QUANTITIES OF SOURED MILK 82
10.--A MILK-FILLING APPARATUS 90
11.--SECTION THROUGH A KEPHIR GRAIN 94
12.--_Streptococcus lacticus_ (GROTENFELDT) GROWING ON
LACTOSE-AGAR, STAINED BY GRAM'S METHOD 96
13.--PHOTO-MICROGRAPH OF PREPARATION FROM ARMENIAN SOURED
MILK (MATZOON) 106
14.--GRANULE BACILLUS FROM YOGHOURT. SHREDDED PREPARATION
OF A FRESH SKIM-MILK CULTURE 110
15.--GRANULE BACILLUS FROM YOGHOURT, CULTIVATED AFTER
THE USUAL AGAR METHOD 110
16.--GRANULE BACILLUS FROM YOGHOURT. AGAR MILK SUGAR
CULTURE 110
17.--_Bacteria W._ FROM MILK, CULTIVATED TWENTY-FOUR
HOURS 110
18.--AGAR MILK SUGAR CULTURE. FROM THE ORIGINAL BULGARIAN
YOGHOURT 112
19.--AGAR MILK SUGAR CULTURE. SURFACE COLONY OF GRANULE
BACILLUS FROM CALF'S STOMACH 112
20.--AGAR MILK SUGAR CULTURE. DEEP-LYING COLONY
OF GRANULE BACILLUS FROM CALF'S STOMACH 112
21.--AGAR MILK SUGAR. COLONY OF _Bacterium W._ FROM
YOGHOURT 112
22.--TWO COLONIES OF _Bacillus Acidophilus_ FROM CALVES'
MANURE 114
23.--BEER-WORT GELATINE 114
24.--SHREDDED PREPARATION OF BULGARIAN ORIGINAL YOGHOURT 114
25.--GRANULE BACILLUS FROM YOGHOURT. CULTIVATED IN SKIM
MILK IN TWENTY-FOUR HOURS 114
26.--_Bacteria W._, AGAR MILK SUGAR CULTURE 116
27.--_Bacteria acidophilus_ FROM CALVES' MANURE 116
28.--MUCUS FROM CALF'S STOMACH INOCULATED INTO MILK AFTER
EIGHT TRANSFERRINGS 116
29.--DIPLOSTREPTOCOCCUS FROM YOGHOURT. PURE CULTURE IN
SKIM MILK 116
30.--PHOTO-MICROGRAPH OF PREPARATION MADE FROM YOGHOURT,
SHOWING YEAST CELLS 118
31.--PHOTO-MICROGRAPH OF SMEAR FROM GREEK CURDLED MILK
CALLED "GIAOURTI" 118
32.--PHOTO-MICROGRAPH OF SOURED MILK INOCULATED WITH
A TABLET CONTAINING VIABLE AND PURE CULTURES OF
_Bacillus bulgaricus_ 120
33.--PHOTO-MICROGRAPH OF MILK INOCULATED WITH A FERMENT
TABLE IN WHICH _Bacillus bulgaricus_ IS NO LONGER
VIABLE 120
34.--PHOTO-MICROGRAPH OF SMEAR OF CULTURE OF _Bacillus
bulgaricus_ 122
35.--_Bacillus bulgaricus_, SHOWING THE CULTURES
IN ENGLISH COW'S MILK 124
36.--PHOTO-MICROGRAPH OF PURE CULTURE OF _Bacillus
bulgaricus_ 124
37.--PHOTO-MICROGRAPH OF SMEAR OF COMBINED CULTURE
OF _Bacillus bulgaricus_ AND _Bacteria
paralacticus_ 124
38.--PHOTO-MICROGRAPH OF SMEAR OF ONE-MONTH CULTURE
OF _Bacillus bulgaricus_ 126
39.--PHOTO-MICROGRAPH OF CULTURE OF _Bacillus bulgaricus_
IN MALT 126
40.--PHOTO-MICROGRAPH OF SMEAR FROM MILK THAT HAD BEEN
ALLOWED TO SOUR SPONTANEOUSLY 126
41.--PHOTOGRAPH OF AGAR CULTURE, INOCULATED WITH A LACTIC
POWDER 128
42.--PHOTOGRAPH OF TEST-TUBES OF STERILE MILK, INOCULATED
WITH A TABLET PREPARATION SAID TO CONTAIN PURE
CULTURES 128
43.--PHOTOGRAPH OF TEST-TUBES OF STERILE MILK, EACH TUBE
HAVING BEEN INOCULATED WITH A TABLET OF A
PREPARATION SAID TO CONTAIN PURE CULTURES 128
44.--PHOTOGRAPH OF TEST-TUBES OF STERILE MILK INOCULATED
WITH A TABLET OF "LACTOBACILLINE" 130
45.--APPARATUS OF "LE FERMENT" CO. 129
46.--SOURED MILK APPARATUS OF THE MAYA BULGARE COMPANY,
LIMITED 130
47.--LACTIC FERMENTS, LIMITED, APPARATUS 131
48.--MESSRS. ALLEN & HANBURY'S SOURED MILK APPARATUS 132
49.--VIRONELLE APPARATUS FOR SOURING MILK, MADE BY
MESSRS. CLAY, PAGET & COMPANY, LIMITED 132
50.--"LACTOBATOR" MADE BY MESSRS. CHARLES HEARSON & CO.,
LIMITED 140
51.--MESSRS. HEARSON & COMPANY'S "LACTOBATOR" 142
52.--EDGAR'S "LACTOGENERATOR," SOLD BY THE DAIRY SUPPLY
CO., LIMITED 143
53.--APPARATUS OF THE WILLOWS REFRIGERATING CO., LIMITED 144
54.--"LACTO" APPARATUS OF THE DAIRY OUTFIT CO., LIMITED 145
55.--STERILISING APPARATUS FOR STERILISING MILK ON
THE LARGE SCALE 146
56.--ANOTHER METHOD OF STERILISING (DAIRY SUPPLY
CO., LTD.). AN AMERICAN APPARATUS FOR PREPARING
SOURED MILK 148
57.--AN AMERICAN APPARATUS FOR PREPARING SOURED MILK 149
THE BACILLUS OF LONG LIFE
CHAPTER I
INTRODUCTORY--HISTORICAL
The milk industry is one of the oldest known to mankind, and it is
difficult to imagine a time when milk in one way or another did not form
a part of the diet of the human race. There is a good deal of evidence
to show that in Paleolithic and Neolithic times, cattle were part of the
possessions of the nomadic races; and, according to the Vedas, the
manufacture of butter was known in India 1500 years B.C.
In the eastern part of Europe, milk has always been looked upon as one
of the principal kinds of food, but not necessarily the milk of cows,
as, from ancient times to the present day, the milk from camels,
buffaloes, sheep, and goats has been used indiscriminately throughout
the East.
According to Layard,[1] "the Bedouins do not make cheese. The milk of
their sheep and goats is shaken into butter or turned into curds; it is
rarely or never drunk fresh, new milk being thought very unwholesome, as
soon by experience I found it to be, in the desert. I have frequently
had occasion to describe the process of making butter by shaking the
milk in skins. This is also an employment confined to women, and one of
a very laborious nature. The curds are formed by boiling the milk, and
then putting some curds made on the previous day into it and allowing it
to stand. When the sheep no longer give milk, some curds are dried, to
be used as a leaven on a future occasion. This preparation, called
_leben_, is thick and acid, but very agreeable and grateful to the taste
in a hot climate. The sour milk, or _sheneena_, a universal beverage
amongst the Arabs, is either buttermilk pure and diluted, or curds mixed
with water.
[Illustration: THE PASS OF BUKOVA.--During the revolution
of 1904, a number of Turkish soldiers, just before
traversing this pass, were given coffee containing "café"
by a Bulgarian coffee-seller, or keeper of a small khan.
Whilst in the pass the poison began to take effect, and
they realized that they had been poisoned. Fortunately for
them, a peasant with three horses loaded with Yoghourt
(soured milk) had taken advantage of their escort. The
soldiers ate freely of the Yoghourt, which counteracted
the effects of the poison.]
"The camel's milk is drunk fresh. It is pleasant to the taste, rich, and
exceedingly nourishing. It is given in large quantities to the horses.
The Shammar and Aneyza Bedouins have no cows or oxen, those animals
being looked upon as the peculiar property of tribes who have forgotten
their independence, and degraded themselves by the cultivation of land.
The sheep are milked at dawn, or even before daybreak, and again in the
evening on their return from the pastures. The milk is immediately
turned into leben, or boiled to be shaken into butter. Amongst the
Bedouins and Jebours it is considered derogatory to the character of a
man to milk a cow or sheep, but not to milk the camel. The Sheikhs
occasionally obtain dates from the cities. They are eaten dry with bread
and leben, or fried in butter, a very favourite dish of the Bedouin...."
The practice is now the same as it was in scriptural times, when milk
was looked upon as the principal article of diet, and throughout the
Scriptures there are copious references to milk in different forms, some
of which are of peculiar interest at the present day.
It may be noticed, for example, that milk is absent from the sacred
offerings amongst the Hebrews, and this was ascribed by the late
Professor Robertson Smith to the fact that all ferments were excluded
from presentation at the altar,[2] it being recognised that, owing to
the hot climate, milk of all kinds became rapidly sour, and in this way
came to be looked upon as only fit for consumption when in that
condition. It has been suggested that the prohibition referred to is on
the same level as the prohibition of the use of blood, "as milk has
sometimes been regarded as a kind of equivalent for blood, and
containing the sacred life."[3] To this day the wandering tribes of
Arabia consider the milk of their camels and flocks more refreshing when
it has been slightly fermented or soured by being poured into a
milk-skin on the inside of which are still sticking sour clots from the
previous milking, and there shaken for a brief period; but this slightly
soured milk (the _Oxygala_ of Pliny) is known widely in the East simply
as leben (milk). The name is also applied to what we term buttermilk.[4]
[Illustration: KABYLES SOURING MILK
In the north of Africa the use of soured milk is common,
and the illustration shows Kabyles shaking a skin full of
milk so as to sour it. The skin has previously been used
for the same operation, and, as a consequence, clots of
milk are left from the previous day's use, and thus
fermentation is set up.]
The use of milk-skins for the carrying of milk is not confined to one
country, as, while it is common all over the north of Africa, it is also
known in the Pyrenees and in some parts of the Balkan Peninsula, the
object being identical in each case; and when it is intended to make
butter from the milk, the skin is simply rocked between the knees until
the butter separates, a process of butter-making which was also used
after the introduction of earthenware churns.[5] Dried soured milk is
also used by the Arabs, and it is reconstituted when required by rubbing
it up with a little water, and it is known as _Meeresy_.[6] The ordinary
soured milk is the common article of diet, and is looked upon as being
necessary at every meal, and travellers frequently refer to the use of
this product, as a few references will show.
Charles G. Addison states: "A supper was brought in on a round tray. In
the centre was a huge pilaff of rice, and around it several small dishes
of stewed meats, grilled bones, sour clotted milk called _yaoort_,[7]
bits of meat roasted, etc....
"We retired into a tent to breakfast, where we found an immense bowl of
delicious fresh camels' milk, with thin hot cakes of unleavened bread,
baked upon the ashes, ready prepared for us. The principal food of the
Bedouins consists of flour and some camels' milk made into a paste,
boiled, and eaten swimming in melted grease and butter; boiled wheat
and beans dried in the sun and prepared with butter are a favourite
dish. They are all remarkably fond of butter and grease; the butter is
made in a goat-skin, suspended to the tent pole, and constantly shaken
about by the women."[8]
Burckhardt[9] says: "The provisions of my companion consisted only of
flour; besides flour, I carried some butter and dried leben (sour milk),
which would dissolve in water. It forms not only a refreshing beverage,
but is much to be recommended as a preservative of health when
travelling in summer. These are our only provisions." With regard to the
inhabitants of the Houran, Burckhardt relates that the most common
dishes of these people are _bourgoul_ and _keshk_. "In summer they
supply the place of the latter by milk, leben, and fresh butter. Of the
bourgoul I have spoken on other occasions; there are two kinds of
keshk--_keshk-hammer_ and _keshk-leben_. The first is prepared by
putting leaven into the bourgoul and pouring water over it. It is then
left until almost putrid, and afterwards spread out in the sun and
dried, after which it is pounded, and, when called for, served up mixed
with oil or butter. The keshk-leben is prepared by putting leben into
the bourgoul instead of leaven; in other respects the process is the
same. Keshk and bread are the common breakfasts. Towards sunset a plate
of bourgoul, or some Arab dish, forms the dinner."
Again, Taylor[10] says: "I received a small jug of thick buttermilk, not
remarkably clean, but very refreshing."
These references particularly refer to the East, from which it would
appear that soured milk was universally known in ancient times as it is
at the present day, and this remark applies not only to Egypt,
Palestine, and Arabia, but throughout Turkey and the Balkan States,
where the consumption of soured milk is equally common. It seems curious
that the use of this commodity should have been confined for centuries
to the East, as we shall see later on that its dietetic value is so
great that it is really a wonderful thing that no one has taken the
trouble to introduce its use to the Western nations until quite
recently.
[Illustration: THE HANDLING OF MILK IN THE PYRENEES
The handling of milk in the Pyrenees is, more especially
in the villages, conducted in goat or sheep skins, in a
similar way to the methods which prevail in Eastern
Europe, and the picture shows a skin of milk on a small
farm in the Pyrenees. The churning is very often performed
by simply rocking the skin between the knees, acidity
being induced by remnants of the previous day's milk;
souring of milk is induced by the same method.]
A curious example of how the virtues of such an article may be
independently discovered by another nation is to be found in Lapland,
where reindeer's milk is the article used. "The reindeer's milk," says
Acerbi,[11] "constitutes a principal part of the Laplander's food, and
he has two methods of preparing it, according to the season. In summer
he boils the milk with sorrel till it arrives to a consistence; in this
manner he preserves it for use during that short season. In winter the
following is his method of preparation: The milk, which he collects in
autumn till the beginning of November, from the reindeer, is put into
casks, or whatever vessels he has, in which it soon turns sour, and, as
the cold weather comes on, freezes, and in this state it is kept. The
milk collected after this time is mixed with cranberries and put into
the paunch of the reindeer, well cleaned from filth; thus the milk soon
congeals, and it is cut out in slices, together with the paunch, to
effect which a hatchet is used, for no smaller instrument would perform
the office of dividing that lump of ice. It is then separated into small
pieces and eaten throughout the winter every day at noon, which is the
Laplander's dinner-hour. It must be presumed, as it is served up without
being brought to the fire, that this is ice-cream in the greatest
perfection: here are flesh and fruit blended with the richest
butyraceous milk that can be drawn from any animal; but, notwithstanding
the extraordinary fatness, which may be supposed to resist in a great
degree the effect of cold, this preparation, as our good missionary
remarks with a degree of feeling, as if his teeth still chattered whilst
he delivered the account, chills and freezes the mouth in a violent
manner whenever it is taken. The milk which is drawn late in the winter
freezes immediately after being drawn. This is put into small vessels
made of birchwood, and is considered by the Laplander as such an
extraordinary delicacy, that he reserves it as the most acceptable
present he can offer even a missionary. It is placed before the fire and
eaten with a spoon as it is thawed. When put by, it is carefully covered
up, because if the cold air gets to it afterwards, it turns of a yellow
colour and becomes rancid."
Amongst the peasants at the present day, soured milk is known as
_yoghourt_, a word which is spelt differently according to the locality
in which it is used. The method of preparation is practically the same
everywhere, and a short description of the process as now carried out
in one place would, with slight modifications, apply to the general
method adopted all over the East.
"The culture," says a correspondent at Varna, "which is used for the
preparation of yogourt, is known as 'Maya' or as 'Bulgarian Maya.' The
milk which is to be converted into yogourt must first be freed from all
bacteria by boiling and allowed to cool to the temperature of 45° C.; it
is then inoculated with maya and maintained at an even temperature of
45° C. during several hours. There are two kinds of maya, or ferment,
one known as sour, and the other as sweet maya.
"In Europe small stoves, made expressly for the purpose, are used to
maintain the milk at the proper temperature. In this country, however,
after the milk has been boiled, it is merely poured into a bowl and
allowed to cool to approximately 45° C., then a tablespoonful of this
tepid milk is well mixed (in a small bowl apart) with a similar quantity
of maya, and the mixture, when it has become quite homogeneous, is added
to the bowl of tepid milk and stirred slightly. (One tablespoonful of
maya is sufficient to ferment one litre of milk.) A cover is then placed
on the bowl and the whole is enveloped in flannel and left in a warm
place for three hours in summer, and somewhat longer in winter.
"The process of preparation is complete when the mixture assumes the
appearance of a soft mass somewhat resembling cream cheese, but less
solid. The flannel is then removed, the bowl uncovered and placed in a
cool spot until needed for consumption. Of the yogourt thus prepared, a
tablespoonful is kept to serve as maya for the following day.
"The best yogourt is prepared from sheep's milk, the second quality from
buffaloes' milk, and the third quality from cows' milk. Yogourt forms an
almost daily article of diet with the natives in this country."[12]
With regard to the time stated for the fermenting process, it must be
noted that since the subject has been investigated so thoroughly, the
time required for fermentation has been found to be nearer ten than
three hours, but this will be dealt with in a subsequent chapter.
Historically it may be gleaned from the fragmentary references which we
have given, that soured milk has, from time immemorial, formed the
principal article of diet of a great many peoples, and the notable
feature in connection with it is, that in some countries where it is in
daily use, the age limit for human beings seems to be very much
extended, and it would appear that there is a direct connection between
the use of soured milk and longevity. In Bulgaria, for example, it is
stated that the majority of the natives live to an age considerably in
excess of what is recognised as the term of life amongst Western
nations, and inquiry has shown that in the eastern part of Southern
Europe, amongst a population of about three millions, there were more
than three thousand centenarians found performing duties which would not
be assigned to a man of sixty-five years of age elsewhere. It is quite
common to find amongst the peasants who live to such a large extent upon
soured milk, individuals of 110 and 120 years of age.[13]
In the ancient dairy practice, as we have seen, soured milk was the
principal product, and the extraordinary ages which are recorded of the
patriarchs, if translated into the modern denomination, would not appear
to be so imaginary after all, when it is considered that we have
thousands of examples at the present day of men and women enjoying quite
as long a term of existence. It has been noticed also, that while these
very old people are able to perform a certain amount of manual labour,
there is not the same tendency to the mental decay which is so prominent
and sad a feature amongst Western nations, at a period of about seventy
or eighty years of age. It would seem, indeed, as if the habit of living
long was well known in ancient times, and that, like many other of the
valuable arts and sciences, it fell under a cloud during the Middle
Ages, or, perhaps, the significance of the use of soured milk fell into
neglect, and, even after the revival of letters in the sixteenth
century, still remained obscure.
The discovery of micro-organisms in perishable products, which is
attributable to Anthony Van Leeuwenhoek, a Dutchman, whose vocation was
the polishing of lenses, and who lived between 1632 and 1723, altered
our point of view, not only of disease, but of all the functions carried
on by the lower organisms. Since Van Leeuwenhoek's time, the germ theory
has grown to vast proportions and has more especially been applied with
splendid results to the study of milk. As we shall see later, the
researches of modern investigators have led them to the conclusion that
micro-organisms play such an important part in the milk supply, that it
is impossible to carry it on safely without a knowledge of the
bacteriology of the subject. This view began to prevail about 1890, some
twenty years after Pasteur had shown what fermentation really meant.
Since that time, the progress in dairying has been continuous, and,
during recent years, attention has been directed to soured milk to such
an extent that it has become necessary for all who are interested in the
handling of milk and milk products to have a knowledge of the subject,
as it seems clearly demonstrated that, under proper direction, there is
every possibility of its forming an important element in the
prolongation of life.