Putnam's
Science Series

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 aretypical examples of people who live to a great age by the use of souredmilk, 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

iii

PREFACE

This book has been designed with a view to meetan extensive demand for definite data on the subjectof Soured Milks. The author has had thismatter brought before him, times without number,by those inquiring for authentic information on thesubject, and he has therefore considered it desirableto gather together such information as isavailable in connection with ancient and modernpractice. He has endeavoured to present this tothe reader in concise form.

The author is indebted to many friends for theirassistance in getting the book together, and wouldspecially mention Dr. H. B. Hutchinson, Bacteriologist,Rothamsted Experimental Station, forassistance in connection with the bacteriology offermented milks; Mr. Thomas Douglas, of Wimbledon,who has assisted with the chemistry of thesubject; Mr. S. Javrilovitch, of Belgrade, Servia,for local information and illustrations; Dr. OtokarLaxa, Bacteriologist, of Prague, Bohemia, forgeneral assistance; the editor of Bacteriotherapy,New York, U.S.A., for the use of the group ofillustrations 30-44; the publishers of the Centralblattfür Bakteriologie, Jena, for the group of illustrations14-29; and many others, some of whomare referred to in the text.

iv

v

CONTENTS