Part 1

BACTERIA IN DAILY LIFE

MRS. PERCY FRANKLAND

FELLOW OF THE ROYAL MICROSCOPICAL SOCIETY; HONORARY MEMBER OF BEDFORD COLLEGE, UNIVERSITY OF LONDON;

JOINT AUTHOR OF "MICRO-ORGANISMS IN WATER," "THE LIFE OF PASTEUR," ETC.

"Spirits, when they please, Can either sex assume, or both; so soft And uncompounded is their essence pure, Not tied or manacled with joint or limb, Nor founded on the brittle strength of bones, Like cumbrous flesh; but, in what shape they choose, Dilated or condensed, bright or obscure, Can execute their aery purposes, And works of love or enmity fulfil."

MILTON.

LONGMANS, GREEN, AND CO. 39 PATERNOSTER ROW, LONDON NEW YORK AND BOMBAY 1903

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Transcriber's Note: Minor typographical errors have been corrected without note. Irregularities and inconsistencies in the text have been retained as printed. Words printed in italics are noted with underscores; italics. The cover of this ebook was created by the transcriber and is hereby placed in the public domain.

PREFACE

The title of this little volume sufficiently explains its contents; it only remains to add that much of the text has already appeared from time to time in the form of popular articles in various magazines. It has, however, been carefully revised and considerably added to in parts where later researches have thrown further light upon the subjects dealt with.

G. C. FRANKLAND

NORTHFIELD, WORCESTERSHIRE, November, 1902

CONTENTS

PAGE

BACTERIOLOGY IN THE VICTORIAN ERA 1

WHAT WE BREATHE 34

SUNSHINE AND LIFE 65

BACTERIOLOGY AND WATER 93

MILK DANGERS AND REMEDIES 118

BACTERIA AND ICE 149

SOME POISONS AND THEIR PREVENTION 168

BACTERIA IN DAILY LIFE

BACTERIOLOGY IN THE VICTORIAN ERA

A little more than sixty years ago the scientific world received with almost incredulous astonishment the announcement that "beer yeast consists of small spherules which have the property of multiplying, and are therefore a living and not a dead chemical substance, that they further appear to belong to the vegetable kingdom, and to be in some manner intimately connected with the process of fermentation."

When Cagniard Latour communicated the above observations on yeast to the Paris Academy of Sciences on June 12, 1837, the whole scientific world was taken by storm, so great was the novelty, boldness, and originality of the conception that these insignificant particles, hitherto reckoned as of little or no account, should be endowed with functions of such responsibility and importance as suggested by Latour.

At the time when Latour sowed the first seeds of this great gospel of fermentation, started curiously almost simultaneously across the Rhine by Schwann and Kützing, its greatest subsequent apostle and champion was but a schoolboy, exhibiting nothing more than a schoolboy's truant love of play and distaste for lessons. Louis Pasteur was only a lad of fifteen, buried in a little town in the provinces of France, whose peace of mind was certainly not disturbed, or likely to be, by rumours of any scientific discussion, however momentous, carried on in the great, far-distant metropolis. Yet, some thirty and odd years later, there was not a country in the whole world where Pasteur's name was not known and associated with those classical investigations on fermentation, in the pursuit of which he spent so many years of his life, and which have proved of such incalculable benefit to the world of commerce as well as science.

Thanks to Pasteur, we are no longer in doubt as to the nature of yeast cells; so familiar, in fact, have we become with them, that at the dawn of the twentieth century we are able to select at will those particular varieties for which we have a predilection, and employ those which will produce for us the special flavour we desire in our wines or in our beers.