Chapter I: Preface

In the following pages I have endeavoured to give some account of the ways in which scientific discovery has been utilised in the struggle between society and the criminal.

I have tried to describe the principles upon which different kinds of scientific evidence are based, and at the same time to bring human interest into what would otherwise tend to be dry detail by giving an outline of trials in which such evidence has been given. It is, perhaps, hardly necessary to mention that in many of these illustrative trials the accused persons were proved innocent of the charges brought against them, and that although their cases were tried in the criminal courts the title of the book in no way applies to them.

For the accounts of the older trials I have drawn freely upon Cobbett's _State Trials_, Paris and Fonblanque's _Medical Jurisprudence_, and the first edition of Taylor's _Medical Jurisprudence_, while I must also acknowledge my indebtedness to the _Circumstantial Evidence_ of Mr. Justice Wills and the recent excellent lectures on _Forensic Chemistry_, by Mr. Jago.

In the later cases I have mainly relied upon contemporary accounts and upon my own impressions of some of the trials at which I have been present.

My best thanks are due to all those who have given me valuable and ungrudging assistance. In particular I would mention Major Richardson, who has kindly given me a photograph of one of his trained bloodhounds and has allowed me to quote the description of an actual man hunt with bloodhounds, from his book, _War, Police, and Watch Dogs_; and Mademoiselle Arlette Clary (and the _Daily Mirror_) who have supplied me with a photograph of a Paris police dog.

I am further indebted to the late Sir Francis Galton and his publishers, Messrs. Macmillan & Co., who gave me permission to reproduce illustrations from his book on _Finger Prints_; and to Mr. Thorne Baker and the _Daily Mirror_ for photographs illustrating the use of telegraphy in transmitting portraits.

The excellent drawings of the hairs of different animals were made by my friend Mr. R. M. Prideaux, and are reproduced here by the kind permission of Messrs. Scott Greenwood & Co.

Finally, I would thank the proprietors of _Knowledge_ and the Editor, Mr. Wilfred Mark Webb, for the loan of various blocks and for permitting me to make use of material from several articles of mine on handwriting, which have appeared in that journal.

C. A. M.

_White Cottage,
Amersham Common,
Buckinghamshire._

CONTENTS

PAGE

CHAPTER I

INTRODUCTION

Conflict between the Law-maker and the Law-breaker--
Illustrations of Deductive Reasoning in Criminal Cases--
Scientific Evidence--Scientific Assistance for the
Accused--Instances of Advantages of Conflict of Scientific
Evidence--Scientific Partisanship 1

CHAPTER II

DETECTION AND CAPTURE OF THE CRIMINAL

Contrasts between Eighteenth, Nineteenth and Twentieth
Centuries--Margaret Catchpole--Tawell--Crippen--Portraits
and the Press--Charlesworth Case--Bloodhounds--Police
Dogs--Circumstantial Detection 22

CHAPTER III

PERSONAL IDENTIFICATION

McKeever's Experiment on Fallibility of Eye-witnesses--
Gorse Hall Murder--Cases of Mistaken Identity--Gun-flash
Recognition--Self-deception--Tichborne Case 37

CHAPTER IV

SYSTEMS OF IDENTIFICATION

Photography--Anthropometry--Finger-prints and their Uses 48

CHAPTER V

IDENTIFICATION AND HANDWRITING

Heredity--Emotional Influences--Effects of Disease on
Handwriting 70

CHAPTER VI

EVIDENCE AS TO HANDWRITING

Illustrative Cases--Handwriting Experts 85

CHAPTER VII

FORGED DOCUMENTS

Use of Microscope--Erasures--Photographic Methods--
Typewritten Matter--Examinations of Charred Fragments--
Forgery of Bank Notes 93

CHAPTER VIII

DISTINGUISHING INKS IN HANDWRITING

Elizabethan Ink--Milton's Bible--Age of Inks--Carbon
Inks--Herculaneum MSS.--Forgery of Ancient Documents 105

CHAPTER IX

TWO NOTABLE TRIALS

Trial of Brinkley--Trial of Robert Wood 116

CHAPTER X

SYMPATHETIC INKS 130

CHAPTER XI

REMARKABLE FORGERY TRIALS

Trials--William Hale--The Perreaus--Caroline Rudd--Dr.
Dodd--Whalley Will Case--Pilcher, etc. 135

CHAPTER XII

IDENTIFICATION OF HUMAN BLOOD AND HUMAN HAIR

Structure of Blood--Human Blood--Blood of Animals--Blood
Crystals--Libellers of Sir E. Godfrey--Trial of Nation in
1857--Physiological Tests--Precipitines--First Trial in
France--Gorse Hall Trials--Human Hair--Hairs of Animals 154

CHAPTER XIII

EARLY POISONING TRIALS

Murder of Sir T. Overbury--Mary Blandy--Katharine Nairn,
etc. 171

CHAPTER XIV

NOTABLE POISONING TRIALS

Use of Poisons--Arsenic and Antimony--Chapman Case--
Strychnine in Palmer Trial--Physiological Tests--Case of
Freeman--Error from Quantitative Deductions--Poisonous Food
Given to Animals--Mary Higgins--Negative Result of
Physiological Tests--Hyoscyamus Poisons--Crippen Case--
Experiment on Cats--Time Limit for Action of Arsenic--
French Case 190

CHAPTER XV

THE MAYBRICK CASE 206