



Produced by Peter Vachuska, Turgut Dincer, Chuck Greif and
the Online Distributed Proofreading Team at
http://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 fuer 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 BACILL