PUBUQ HEALTH UBRARY LEGAL CHEMISTRY AND SCIEKTIFIC CRIMINAL INYESTIGATION LEGAL CHEMISTEY AND SCIENTIFIC CEIMINAL INVESTIGATION A. LUCAS, F.I.C. DIBECTOB GOVERNMENT ANALYTICAL LABORATORY AND ASSAY OFFICE, CAIRO FELLOW OF THE CHEMICAL SOCIETY ; MEMBER OF THE AMERICAN CHEMICAL SOCIETY ; MEMBER OF THE SOCIETY OF P0BLIC ANALYSTS, ETC., ETC. LONDON EDWAED AKNOLD 1920 [All rights I'cserved] n PUBUC LIBRARY PEEFACE ^ I ^HIS book has no pretensions to be a complete treatise on Legal Chemistry, but consists essentially of a collection of notes. These notes have been put together in the hope that they might prove useful to those engaged in similar work, and might also serve as some indication of the nature and extent of the services chemistry can render in the administration of justice. The notes are very partial and incomplete and often very detached. This is intentional, as it was thought that the modest results of the author's own experience would fulfil the purpose of the book better than a more pretentious volume compiled largely from the material already published by others. There is intentional incompleteness also with regard to the books of reference mentioned, works on general analytical methods having been excluded, as also works, even on the special subjects dealt with, which in the author's opinion are not likely to prove useful. In some instances the edition of a book referred to may not be the most recent, but this arises from the circumstance of the author's residence abroad, where the latest editions of scientific books are not always available. Since the book is the outcome of the author's experience in Egypt the illustrations have necessarily been drawn almost entirely from that country, but the habits of criminals being 42'i234 vi PREFACE very similar throughout the East, the methods of investi- gation and detection found suitable in Egypt are equally applicable to India and the far East. The author's thanlis are particularly due to Mr. G. H. Hughes, Chief Inspector of the Native Parquet, Cairo, for his keen appreciation of the value of scientific evidence and for much sympathy and help. January, 1920. A. L. CONTENTS PAGE Preface v Introduction 1 Notes on Cases 17 Alcoholic Liquors 19 Antiquities 35 Blood Stains 39 Building Materials 40 Bullets and other Projectiles for Firearms .... 46 Clothing 51 Counterfeit Coins 57 Damage to Crops 63 Documents 65 Dust and Dirt 102 Explosives and Explosions 104 Fibres 108 Finger Prints 114 Fires 117 Firearms 122 Foods and Drugs . . ' 134 vii viii CONTENTS PAGE Gold and Silver Wares 140 Hashish 142 Poisons 145 Pollution of Water by Sewage 150 Robbery from Letters and Parcels 153 Stains and Marks 161 String and Rope 165 Textile Fabrics 166 Tobacco 169 Traps for Criminals 171 Index 177 INTRODUCTION Definition of Legal Chemistry. Legal, or forensic chemistry, may be defined as chemistry applied to the solution of certain problems which arise in connection with the administration of justice. It is chemistry exercised in the service of the law. The chemical enquiry constitutes an expertise and the chemist who conducts it is an expert. Scope of Legal Chemistry. The scope of legal chemistry is very wide and the bound- aries of the subject are very ill -defined. Not only does it include the chemical side of criminal investigation, with which it is generally associated in the public mind, but it is also concerned with the analysis of any material the quality of which may give rise to legal proceedings. Legal chemistry, too, deals not only with purely chemical questions, such as the nature, composition and quality of materials as deter- mined by analysis, and the examination of articles for the presence or absence of particular substances, such as poisons, but it is concerned also with questions which are only partly chemical, as for example the examination of blood stains, questioned documents, counterfeit coins, fibres and textile fabrics, and the expert in legal chemistry should be not only a capable analyst, but also an experienced micro - scopist and photographer. Practice of Legal Chemistry. The practice of legal chemistry naturally resolves itself into three stages, namely (1) the reception of the article to 2 r^XKGAL 'CHEMISTRY be examinee(;:(3'j.'the 'examination;. and (3) the communication of the results. These three stages may usefully be con- sidered in detail. Before an expert commences his work he receives a formal mission or mandate, and whenever possible he should make sure that this is not worded in any way calculated to limit adversely or cramp his enquiry. This danger may be avoided if the mandate contains a general clause to the effect that, in addition to the particular investigation specified, the expert is empowered to carry out any other investigations found necessary in the course of his work. 1. Reception of the Article. — It is most important that whenever possible the expert should himself personally take such articles as are required for examination. Unless this is done, something essential to the elucidation of the problem may be omitted, or the articles may be taken, handled or packed in such an unsatisfactory manner as to render them almost useless for purj^oses of investigation. Sometimes too, in criminal investigation, it is necessary that the expert who examines an article should know the precise condition, and even the position, in which it was found, and this can only be done when he is called in at the very commencement of the enquiry and before anything is disturbed or removed. It is impossible to lay too much stress upon this point, for just as finger-prints or foot -prints may be obliterated and thus valuable evidence lost, so other clues may be destroyed or even misleading indications may be produced. Whenever possible therefore in all cases of criminal investigation in which a chemical expert is consulted, he should make a detailed examination of the scene of enquiry and should take full notes with sketches and measurements and also any samples that may be required. A sketch as neatly and accurately drawn as possible witli all the important measurements recordetl will be found a great help in writing the report. This sketch, however, should not be reproduced in the report. If a plan is necessary to illustrate the report only one made by a trained surveyor should be used.^ In the case of a fire, explosion or similar occurrence, as much ' Application of Surveying to ( rimiiuil Investigation, F. C. Hirst, Calcutta, 1915. INTRODUCTION « 3 information as possible should be obtained regarding the exact previous condition of things, also an account of what was seen or heard at the time and the explanation that is given of the occurrence by those concerned. It should be remembered that generally it is difficult or impossible to repeat a visit, and that, unless full details are obtained in the first instance, the report will be incomi)lete and, in the absence of some small fact, which has been omitted, it nay be found impossible to express a definite opinion or to explain what might otherwise be a very simjjle matter. Special care should be taken to make the notes not only full but neat and clear, since it may be necessarj^ to produce them in Court. There can be no excuse for a careless super- ficial examination or for any inaccuracy in recording the facts. When summoned to the scene of enquiry the expert should go fully prepared for all eventualities and should take with him everything that can possibly be required : a lens, or preferably a reading glass with a handle, a penknife, a few small round cardboard boxes for samples and a measuring tape will generally be found useful, and a no^^-book and pencil are indispensable. The note-book should be of good quality and not too small a size and the pencil should be an indelible one. A camera is also fre- quently of service. In the majority of cases, however, the exjDert will not have the opportunity of taking his own samples, but these will already have been taken before he is called in, and at the most he will be asked to fetch them from the Court. Gener- ally, however, the sam-ples will be handed or forwarded to him. As no conclusions of value can be formed without a full knowledge of all the facts, no opinion whatever should be given until the articles have been fully examined and the m.atter carefully considered. As soon as practicable after an article has been received it should be registered, and the register should show the date and hour of receipt, from whom received, the nature of the article and full details of all numbers or other dis- tinguishing marks. 4 . LEGAL CHEMISTRY At this stage the jjackage should not as a rule be opened but, whenever it is opened, this should be done by the expert himself. It is convenient to keep one general register in which the particulars enumerated above are recorded and in which all articles received are entered in order of date, each being given a sjDecial number, the numbers being consecutive in any one year. The serial number of the article and the year should be marked on the outside of the package. When the expert himself takes the samples, particulars should be written on each at the time and full and exact notes made as to when and how and under what circumstances they were taken and, immediately on arrival at the laboratory, they should be registered and numbered in the usual manner. If a large number of articles of any one kind are being con- stantly received it will be found convenient to have more than one general register, though it will rarely, if ever, be necessary to have more than two, one for the class of articles that predominates and a second for miscellaneous cases. In addition to the general register or registers, however, a series of abstracts, one for each kind of article, in which the results of the analyses are summarized, will be found useful. These are for quick reference to the details of the cases. In the Poisons abstract, for example, there would be a separate page for each kind of poison found and another for cases where the results were negative and, under each heading, the cases would be entered in numerical order, with details in tabular form showing the nature of the article analysed and the amount of poison present. In the Counter- feit Coin abstract, such particulars as the denomination of the coin, the year, weight, specific gravity, composition and whether struck or cast, would be given in tabular form. Thus at a glance the number of cases of any particular kind and the details of each case can be seen. With regard to the reports, an exact copy of each must be kept and, as these are frequently too lengthy to be conveniently transcribed into a register, it is generally best to keep typed copies in separate files according to the nature of the case, though a brief summary in the general register will be found useful. The general register should also show the number and page INTRODUCTION 5 of the laboratory work book in which the original facts and figures were entered at the time the article was examined. Articles are frequently very badly packed and very in- adequately marked. This is not the fault of the expert but, by drawing attention to it each time it occurs, improvements in this respect may be brought about. The commonest faults are the use of wet or dirty bottles, dirty corks, insuffi- cient protection of glass vessels during transit, the use of thin cardboard boxes which cannot be closed securely and which easily break or become forced out of shape, and so allow the contents to escape, the use of ordinary correspon- dence envelopes from which finely powdered materials always leak, the packing of several articles in one parcel in such a manner that contamination of one with another is almost inevitable, and the use of sealing wax on the corks of bottles containing alcoholic liquors or other liquids in which sealing wax is soluble. Many articles too are received without sufficient marks of identity or else bear such marks only on the outside wrapper which has to be removed. It does not seem to be sufficiently recognized that ordinary gummed labels do not adhere well to tins or to painted or glazed surfaces, with the result that such labels frequently come off and the articles are left without any means of identification. For small samples of dry material the round cardboard boxes, which are sold in nests of different sizes, will be found very useful. Oblong envelopes with the opening at the end are also very satisfactory, and such envelopes are made in all sizes specially for holding samples, and many have ingenious methods of fastening. As already mentioned, ordinary correspondence envelopes are most unsuitable and should on no account be used. 2. The Examination. — The first step in the examination of an article is to scrutinize it carefully and to write down in the laboratory note -book i a full description of its appear- ance. The outside of the package, the manner in which it is secured and particulars of the seals, if any, should first ' The note-book should be of good quaUty, with ruled paper and a stiff back, Avhich should not be of the glazed black material so often used, but of some substance on which it is possible to write. All entries in this book should be in ink. 6 LEGAL CHEMLSTRY be described. The package should then be opened and any inner wrappings or packages should be examined and described, and finally a detailed description of the appearance of the article itself should be given. This will be found very helpful, since before an article can be described it must be carefully and minutely examined and definite conclusions must be arrived at on such points as colour, shape, size and other physical characteristics which might otherwise be left vague and inconclusive. The serial number, which was originally marked on the outside wrapper, should now be put on the article itself, if that be possible, or, if not possible, then on the innermost ]mckage. When however the article consists of a written or printed document this should not as a rule be numbered or marked in any way, as by inadvertent^ covering uj) some- thing of importance the value of the document as evidence may be seriously impaired, and what is, or is not, of impor- tance frequently cannot be recognized until the document is critically examined. As an example of the lack of care with which documents are sometimes treated the following case may be cited. On one occasion when dealing with an anonymous letter it was found that the mode of formation of the capital letter I, and whether it was made with one stroke of the pen or in two strokes, was of the utmost importance, and this letter only occurred twice in the whole document and one of the two occurrences had been mutilated by perforating the document for filing. Occasionally how- ever when there are a number of different documents, which must be referred to separately in the report, it will be found convenient to mark them with a distinguishing letter or number, but this should be done carefully and generally in one corner. The practice adopted by some experts of placing their name or initials on all documents as a means of identification is unnecessary. If a document has been carefully examined and described it can always readily be identified again. In the case of some articles, i)articularly those made of metal, it is not always possible to mark them. Coins however, which are generally much alike and which may ea'^ily be confused, should always have a distinguishing mark or number scratched on them. Frequentl}^ considerable INTRODUCTION 7 trouble is caused during a trial, in which there are a large number of different exhibits, by the confusion of similar articles or by mistakes in identification due to insufficient or unsatisfactory marking. The original package should be opened in such a manner that if possible the seals remain intact, since sometimes questions arise concerning the identity of the seals and further examination of them may be necessary. All wrappers should be kept. Before opening any package it should be seen that the table on which this is done is clean and un- encumbered with other articles. From the time the package is opened until the examination is finished and the article finally sealed up again it should never leave the personal custody of the expert and should not be left about the laboratory or be unnecessarily exposed in any way ; when not actually required it should be kept in a locked room or cupboard to which the expert alone has access. The method of examination will naturally depend upon the nature of the material, but in every case special care should be taken that the apparatus and vessels used are clean, that the re -agents are pure and that the analysis is conducted in such surroundings and in such a manner that contamina- tion or loss is impossible. It is not merely sufficient for the expert himself to be convinced that all these things are as they should be but he must be in a position to convince others. For example, he may feel certain that the re -agents employed are pure but he cannot definitely refute a state- ment to the contrary unless he has the positive evidence that can only be obtained by having tested them. During the Maybrick trial one of the witnesses, a medical man, who had made a preliminary test for arsenic, when asked about the purity of the copper and hydrochloric acid employed, could only say with regard to the copper " I do not know whether the copper was absolutely pure but I have a strong impression that it was pure,"' and with regard to the acid, that he had bought it from a " good chemist." ^ Blank or control experiments should be made whenever jDossible. At every stage full notes should be made in ink in the laboratory I Notable English Trials : Mrs. Maybrick. Edited hij H. B. Irving. 8 LEGAL CHEMISTRY note-book. Pencil notes and scraps of paper should never be used. Some of the precautions mentioned may possibly appear very trivial and unnecessary, but exi^erience proves that none of them can safely be dispensed with, and the neglect of any one may seriously discount the value of the most careful analysis or even invalidate it altogether. Thus, for instance, the authenticity of an article may be challenged and it then becomes necessary for the expert to prove, not only that it has never been out of his custody since he first received it, but also that it is impossible it could have been tampered with in any way or that anything could have been added or abstracted. It should not be forgotten too that the chemico-legal expert occupies a very different position from that of the ordinary analyst in that everj'thing he does is liable to be subjected to the strictest scrutiny and adverse criticism, and his work is either done on oath or the results must be sworn to.' Moreover where the liberty or even the life of another is concerned it is impossible to take too much care. The second step in the examination of an article requiring chemical analysis is as a rule to weigh or measure it, after which, if possible, it is divided into several i3ortions, one being kept in its original condition for further reference or for production in Court. All weights and measures should be entered directly in ink in the laborator\' note-book at the time they are determined. The third step is the chemical analysis, microscopical or other examination or physical testing, whichever may be indicated. It is not proposed as a rule to describe the methods employed, since before a cliemist specializes in legal cases he will naturally have had experience in general analysis, and he will be familiar therefore with the usual ' In Egypt the oath is taken before tlie work is commenced. In the INIixed Courts the oath is taken each time. This was also the practice in the Native Courts until the law of January 1, 1917, by which any Government official, who by reason of his technical know- ledge is, or could be, constantly called as an expert before the judicial authorities, could take the oath once for all before the I'resiflent of the Court of Appeal. The expert, however, is sworn again each time he gives personal evidence in Court. INTRODUCTION 9 methods and processes and will also know where to find the description of additional methods should he require them. For matters which are outside the range of an analyst's ordinary work special books must be consulted and the names of a few such books will be given in con- nection with the various subjects dealt with. Certain types of cases however, such for example as those concerning questioned documents, fires, explosions, robbery and stains and marks, will present different aspects and new features every time, and the methods of dealing with them can only be learned by practical experience. In the description of actual investigations that follows some account will be given of the methods adopted in special cases. Any important ingredient separated in the course of an analysis should be preserved for production in Court. After the examination or analysis is finished, the article or residue should be securely sealed, and either kept for production in Court or handed over to the proper authorities. It is preferable that whenever possible the expert should retain the articles he has examined and should himself produce them in Court, as few people realize the importance of the proper care of exhibits. The expert will generally have some help in his work but he must personally conduct all the important operations and should see and verify everything else that is done and form his own conclusions independently of the opinion of others, since it is he who is responsible and it is he who will make and sign the report or give evidence in Court, and he must therefore be in a position to describe both the article itself and the method of its examination and to justify the conclusions arrived at. In the practice of legal chemistry there are six golden rules which should never be lost sight of. These are : — (1) Go slowly : good work cannot be hurried, therefore take all the time necessary to make the case complete, no matter how urgent it may appear or how pressing others may be for the result ; it is generally possible to adjourn a case if the work cannot be finished in time. (2) Be thorough : make a careful and minute examina- 10 LEGAL CHEMISTRY lion of everything and do not be satisfied with a qualitative analysis if a quantitative one be possible ; it always pays to do too much rather than too little and it is difficult to foresee w^hat will or will not be required in Court. (3) Take notes : keep a full, neat and clear record of everything seen and done. (4) Consult others : many cases will lead the expert into paths with which he is not familiar, and when this happens he should consult those who are most likely to know. Unless an expert knows his subject thoroughly, or unless he consults others, he may go seriously astray ; thus a doctor, who found salt in an Egj^ptian mummj^ reported it to be that of a person who had been drowned in salt water, apparently quite in ignorance of the very readily ascertained fact that crude natron, which contains a large percentage of salt, and at a later date, salt itself were commonly used in ancient Egypt in connection with the preservation of the body. The chemist too who thought that the ancient Egj^ptians used quicklime as a body preservative, because he found a small amount of carbonate of a lime in a mummy, was evidently unaware of the extent to which limestone and limestone dust occur in Egypt and that burial in tombs cut in the limestone rock was very common. Another expert, who had not made himself familiar with the methods of using liquid fuel under a boiler, but who had evidently heard of the use of compressed air in that connection, thought that compressed air was forced into the oil in the feed tank. (5) Use imagination : this is somewhat hazardous advice, since an expert with a vivid and uncontrolled imagination is a most dangerous person ; a disciplined imagination, how- ever, which enables inferences and deductions (to be verified or discarded at a later stage) to be made from slender and incomplete premises is often very useful. In writing the report the imagination must be kejjt well in hand and the expert should remember that what to him may be merely a helpful working hypothesis is liable to be taken by others for more than its true worth and to be adopted by them as a final explanation. (0) Avoid com]")licated theories : the simj)lest explanation is the most likely to be the right one. INTRODUCTION 11 3, Communication of the Results. — Tlie results cf the work carried out will generally be communicated in the form of a written report, which may be supplemented at a later date by oral evidence. In Egypt the written rejoort is generalh^ sufficient, though occasionally the expert is required to give personal evidence in Court. Both the written report and the oral evidence therefore will be considered. The written report should consist of a brief but sufficient record of all the significant facts noted during the examina- tion of the article, followed by a summary of the conclusions drawn from the observed facts and from these alone, the conclusions, however, being kept quite distinct from the facts and the whole being expressed in plain and non- technical language. The conclusions arrived at should be given very definitely and without ambiguity, vague and inconclusive oj)inions being useless. This, however, does not mean that the expert should dogmatize on insufficient data, and it is sometimes necessary to state that the facts are so few or so obscure that no definite conclusions are j)ossible. All opinions should be supported by the evidence on which they are formed, that is to sslj every statement made should be proved and unless a point can be proved to the satisfaction of others it will generally be found to be worthless. In the case of articles, such as foods and drugs, where a definite minimum standard of composition exists, a bald statement that the material is adulterated is not enough, sufficient analytical data should be given to enable the Court to form a conclusion as to whether an offence has been committed or not. In the case of alcoholic liquors where there are no legal standards, it is generally better to refrain from giving figures in the written report unless two samples are to be compared ; if necessary the figures can be given and exj)lained in Court. In ordinary gravimetric or volumetric analysis it is neither necessary nor wise to report the results to more than one decimal place, as although the weighings, measurings and calculations will probably be carried out to two or even four 12 LEGAL CHEMISTRY decimal places, yet the errors inherent in the method, apparatus and manipulation are such that anything beyond the second decimal cannot possibly be correct and even the second decimal is very liable to be wrong. In some cases, however, such as the analysis of water, sewage and poisons, the results must frequently be given to tenths, hundredths or even thousandths of a milligram. Thus in the Seddon trial » quantities of metallic arsenic varying from .r\,th to .joVo^^^ V^^^ of ^ milligram were obtained by the anatyst from the various samjjles. It is not, as a rule, necessary to mention how an analysis or examination has been conducted and therefore, whenever possible, all references to methods should be omitted as their inclusion only lengthens and complicates the ref)ort. Sometimes, however, it is useful to state tliat the analysis has been conducted by well-known methods, which are mentioned by name, or by the methods adopted by, say the Government Laboratory, London, or the Paris Municipal Laboratory, or the Society of Public Analysts, as the case may be. The one endeavour in writing the report should be to make it as precise and clear as possible. Utility, however, should not be sacrificed to brevity, and the report should be sufficiently full and explanatory to meet any adverse criticism it ma}^ encounter, containing within itself the replies to any arguments likely to be directed against the conclusions arrived at, since, as a rule, the expert will not be able to supplement his report by further details or explanations. If micro -photographs or photograjDhic enlargements of objects have been made, a copy of these should be attached to the report, and it should be clearly stated on the photo- graphs what they represent, and any special points illustrated should be indicated. After drafting a report and before it is finally copied and forwarded it will be found a useful check on the correctness of the conclusions for the expert to ]nit himself mentally in the ])lace of the counsel for the o])posite side and to scrutinize the report carefully from that ]ioint of view, more particu- larly as to whether the data are suificient to justify the ■ Notable Enplisli Trials : Tho 8o ' 80 100 38 100' 100 300 300 340 400 250-300 'lloyal Commission on " Whisky and other Potable Spirits," 1909, vol. ii., 124, , 170, 220. J. Soc. Chem. Ind., 1896, 913; 1897.253. ./. Soc. Chem. Iiid., 1897, 157. Analyst: 1903, 74. " Foods," London, 1909, 398. Subject to an allowance of 10 per cent. The author's experience from the examination of many hundreds of samples of l)randy may be briefly summarized as follows : — ALCOHOLIC LIQUORS 23 1. That a good quality genuine French brandy always contains more than 300 milligrams of secondary products per 100 cubic centimetres of absolute alcohol. 2. That a good quality genuine French brandy generally contains more than 80 milligrams of esters per 100 cubic centimetres of absolute alcohol, although this is not invariably the case, and the esters may be only about 60 milhgrams. 3. That French brandy which is genuine, but not of the finest quality, may contain not more than between 200 and 250 milligrams of secondary products and esters as low as 35. Generally, however, the secondary products are above 300 and the esters above 45. 4. That all samples of French brandy with less than 200 milligrams of secondary products are of doubtful purity and when the secondary products fall below 150 the sample is certainly not genuine. 5. That genuine brandy from Greece, Crete, Cyprus, Egypt, Palestine and Turkey approximates very closely to French brandy in composition, except that the higher alcohols are sometimes much lower, and in consequence the total secondary products may also be less. Whether this is due to the nature of the wine or to the method of distillation or to both, has not been investigated, but it seems probable that it is caused by a greater degree of rectification than is usual in the case of French brandy. It should be remem- bered, however, that any brandy-flavoured liquor made from the fermented juice of fresh grapes is brandy, no matter what its mode of manufacture or its chemical composition may be, and any particular method of manufacture now employed in France or elsewhere may give place to different and improved methods at any time, with a corresponding alteration in the nature and proportion of the secondary products present in the finished product. It has been recently stated "^ that a decrease is taking place in the higher alcohols of French brandy, doubtless due to a different method of distillation. The amount of plain spirit added to a brandy cannot be determined directly, but may be calculated approximately ' J. Soc. CJtem. Ind., 37, 345a. 24 LEGAL CHEMISTRY by assuming a minimum amount of esters or total secondary products for genuine brandy. In making this calculation the nature of the plain alcohol known to have been used, or likely to have been used, should be taken into account and allowance made for the esters or secondary products present. Whisky. — The Select Committee on British and Foreign Spirits (1891) defined whisky as " a spirit consisting of alcohol and water with a small quantity of bye-products coming from malt or grain which give it a peculiar taste and aroma." The Royal Commission on Whisky and other Potable Spirits (1909) defined whisky as "a spirit obtained by distillation from a mash of cereal grains saccharified by the diastase of malt " and Scotch whisky and Irish whisky as whisky as above defined distilled in Scotland and Ireland respec- tively. This latter definition is similarly defective to two of the definitions of brandy since it lacks any reference to aroma and flavour and, to make it complete, a clause should be included to the effect that the spirit must possess the char- acteristic aroma and flavour always associated with whisky. The definition as it stands tacitly includes highly rectified featureless spirit if it be made from cereal grains. Such a spirit, however, is not whisky. The following definition is suggested : " Whisky is a potable spirit prepared by the distillation of a mash of cereal grains saccharified by the diastase of malt, the materials being fermented and distilled in such a manner that certain ingredients which impart a characteristic aroma and flavour are developed and retained." According to such a definition the addition of spirits, which (even though prepared from cereal grains) on account of the high degree of rectification to which they have been subjected, do not possess the special ingredients which impart the characteristic aroma and flavour would constitute adul- teration. The above definitions by excluding any mention of the type of still to be used admit that patent still spirit, if made from cereal grains saccharified by the diastase of malt, is just as much whisky as pot still spirit. The various standards therefore, such as that proposed by Dr. Teed, with a view ALCOHOLIC LIQUORS 25 to excluding patent still spirit, become inapplicable. Dr. Teed's suggested standard was a minimum of 380 milligrams of total secondary products per 100 cubic centimetres of absolute alcohol. The minimum limits for whisky imported into Western Australia are also useless as general standards, since these only apply to pure pot still spirit or to blends containing at least 50 per cent, of pot still spirit. These standards are as follows : — MUligrams per 100 c.c. Absolute Alcohol. Esters. Furfural. Higher Alcohols. Pot still whisky Minimum. 45-0 Minimum. 3-50 Minimum. 180-0 75 per cent, pot still whisky 40-0 2-00 140-0 50 per cent, pot still whisky 350 1-75 110-0 If the definition of whisky adopted by the Royal Com- mission be accepted even with the proposed addition, then any liquor having a whisky character if it is made from malt, or from a mixture of malted and unmalted grain, must be passed as whisky no matter what the analytical results may be, and the examination practically resolves itself into smelling and tasting the sample to see whether it has a whisky character, since the nature of the ingredients from which a spirit is made cannot be determined by analysis. If, however, the quality of the spirit is required and if it is desired to know whether it is a pot still or a patent still product or a blend of the two, or whether it is a whisky of a particular brand, or whether the description on the label is correct, then a full analysis becomes necessary. No attempt should be made to lay down hard and fast standards and any fixed limits for esters or other ingredients or for total secondary products are arbitrary and unjustifiable. Each case should be judged on its own merits and in relation to the particular description attached to the sami)le and 2G LEGAL CIIEMLSTRY analysis should always be accompanied hy tasting and smelling. The whisky imported into Egypt from the United Kingdom conforms entirely, or almost entirely, to the definition laiil down by the Royal Commission and is therefore genuine whisky, though some of it is purely patent still sj^irit with very little flavour or aroma. In some cases however the description is altogether misleading, the liquor being called " fine," " old/' " fully matured " when such is not the case, and the labels sometimes bear the names of non- existent firms and fictitious illustrations of awards given at various exhibitions. Of the whisky produced locally the greater part at one time was imitation made by the addition of essences and colouring matter to plain alcohol. In order to protect the British troops in Egypt this particular industry was made a punishable oifence in 1915 and practically ceased. Genuine whisky however has been made in small quantity in Egypt for many years and this industry has recently increased. The imitation whisky referred to was frequently filled into empty bottles bearing the original labels of much advertised and well-known brands, or bore forgeries of genuine labels, some of which resembled the originals very closely, though others were very crude. Some of the labels found have been so badly worded, badly spelled and badly printed that they could not possibly deceive any one acquainted with English, though apparently they did succeed in deceiving many people not knowing English. As illustrations of these latter the following examples may be quoted : — 1. Scotch Whisky. Wliite and Yellow {sic). As specially selected for the Royal House. Calvier Sons, Scotch Whisky Distilleis, Glasgow, Leith and London. Report of Government. Anatylical {sic) chemical this to certify that it having been swred {sic) in wine casks and it con- sists with genuine pot still spirits from the fine character of the sample. 2. A variation of No. 1. Genuine Scotch Whisky. White and Yellow. As specially selected for Royal Houses. Anonimus Society, Scotch Whisky Distillers, Glasgow, Leith and London. ALCOHOLIC LIQUORS 27 3. B.B.B. A'ery Old Wliisky Scotcy {sic). Cassius, Diamond and Devotion. 4. Helwet Special Old Scotch Whisky. Bottled and Guaran- teed by the Whisky Distillers and Kriejer (sic) & Co., Limited. London and Liverpool. Specially bottled in Glasgow, Scotland. Hetwert Special. The copy of the analytical certificate on the bottle bore the name N. I. Rah way. Public Analisto (sic) and Consulting Chemist. Another and somewhat similar certificate was signetl C. Logwood. It is not known whether the above were local productions or not. Rum. — Rum was clejfined by the Select Committee on British and Foreign Spirits (1891) as "a spirit coming from cane-growing countries and consists of dilute alcohol flavoured with the bye-products of the cane sugar or molasses." The Royal Commission on Whisky and other Potable Spirits (1909) gave practically the same definition, namely " a spirit distilled direct from sugar-cane products in sugar-cane growing countries." Here again, as in the case of both brandy and whisky, there is in one instance no mention of aroma and flavour. In Egypt the only industrial spirit produced is made from molasses and, since Egypt is a sugar-cane growing country and molasses are a local product, this industrial spirit there- fore, under the definition, would be classed as rum, which is manifestly absurd. A number of cases have actually occurred in which persons accused of making or selling as rum a liquor confessedly made by colouring with caramel industrial spirit made from molasses have urged as a defence that all the articles used being sugar-cane products and Egypt being a sugar-cane growing country, the liquor, therefore, must be rum. Liquor so made naturally has none of the characteristic aroma or flavour of rum and frequently tastes strongly of caramel and is certainly not rum. After several successful prosecutions for the sale of this liquor as rum it is now described as Tafia, which is allowed. Genuine rum, however, is made in Egjqjt in considerable amount. Spirit before it can reasonably be called rum must possess 2S LEGAL ClIKMLSTRY tlie an^nui and flavour cluiraitciistic of rum. It is true lliat rums from different parts of the world dilfer considerably, not only in the nature of the aroma and flavour, but also in the extent to which these are present, though all possess aroma and flavour to at least some extent and this is funda- mentally the same, although differing in degree, and a spirit without this aroma and flavour is not rum. Even with the addition of a clause specifjang that the spirit must possess the character of rum the definition is very wide and the analyst is obliged to pass molasses spirit as rum if it has a slight rum character. The following definition is suggested : — " Rum is a potable spirit prepared by the distillation of the fermented juice of the sugar-cane, the material being fermented and distilled in such a manner that certain in- gredients which impart a characteristic aroma and flavour are developed and retained." According to such a definition the addition of spirits, w^hich (even though prepared from the juice of the sugar-cane) on account of the high degree of rectification to which they have been subjected, do not possess the special ingredients which impart the characteristic aroma and flavour, would constitute adulter- ation. The British Customs divide rum into three classes, namely Jamaica rum, rum from other sugar-producing countries and imitation rum, which latter comprises all spirits possessing rum character imported from countries in which the sugar- cane is not cultivated. No suggestions for a minimum analytical standard for rum can be traced but only various standards for the ester value of Jamaica rum ; tlius one authority (Mr. John Heron) suggested to the Royal Commission a minimum value of 200 milligrams per 100 cubic centimetres of absolute alcohol, and another authority (Dr. Teed) suggested a minimum of 150 milligrams. Gin. — The Select Committee on British and Foreign Spirits (1 89 1) did not define gin, nor did the Royal Com- mission on Whisky and other Potable Spirits (1909), though this latter quoted, and apparently accepted, several definitions submitted to them, all of which agree in substance. These ALCOHOLIC LIQUORS 29 definitions limit gin to a potable spirit produced from grain and flavoured by re-distillation with juniper berries and various herbs. Zebib, Mastic, Arak (Araki or Araqi). Zebib is essentially a Coptic drink and strictly speaking should be made from raisins, the Arabic name of which is zebib. In practice, however, zebib is made from any plair alcohol. It is flavoured with aniseed. Mastic is also an aniseed-flavoured spirit very like zebib and is largely drunk by Greeks. In Egypt it is made from any plain spirit. Genuine arak as made in Egypt is generally a spirit dis- tilled from fermented dates and none of the few samples of this spirit examined have been flavoured artificially either with aniseed or other ingredients. Syrian arak, however, which is imported into Egypt, is invariably flavoured with aniseed, and is sometimes called eau-de-vie anisee. Imitations of Syrian arak are made in Egy23t. Sometimes a spirit slightly flavoured with aniseed and called " balah " is met with. As balah is the Arabic name for a date this is probably a date spirit. With regard to spirits like gin, zebib, mastic, etc., the analyst can do very little, as there is no generally accepted method of manufacture and no standard of composition. Liqueurs. — Liqueurs are mostly proprietary articles whose composition and mode of preparation are kept secret. They consist of sweetened spirit flavoured with herbs and spices, the aromatic princif)les of which are extracted by means of alcohol. Liqueurs are rarely, if ever, adulterated, but imitation liqueurs made from plain alcohol, sugar and flavouring essences and bearing false and misleading descriptions are very common. With respect to liqueurs there are no standards, but analysis will sometimes prove that a so-called cherry brandy for example has been made from plain spirit and not from brandy, and taste will show that the flavour is not that of natural cherries but is derived from an artificial essence. 30 LEGAL CHEMISTRY Essences and Extracts. — These have already been men- tioned in connection with the manufacture of imitation brandy, whisky, rum and liqueurs and until 1915 they were imported into Egypt in comparatively large amount, coming chiefly from England, Italy and Germany. These essences or extracts, the names being more or less synonymous, are freely advertised. The catalogue of one well-known English firm quotes the following among others : — Essence of Cognac Brandy ; Essence of Scotch Whisky ; Essence of Irish Whisky ; Essence of Bourbon Whisky ; Essence of Rye Whisky ; Essence of Jamaica Rum ; Essence of Plymouth Gin ; Essence of London Gin ; Essence of Hollands Gin and Essences of most of the well known liqueurs. Several samples of essences of brandy, whisky and rum have been analysed and found to contain one or more of the following, namely esters, aldehydes, furfural and fusel oil. It is not stated that these essences and extracts are in- jurious to health in the proportion in which they occur in the finished liquor and possibly they are not, nor is it con- tended that liquors made with essences or extracts should not be sold if they are properly labelled, but it is contended that if sold they should be so described that the purchaser may realize exactly what he is buying, and that the liquor is not genuine brandy, whisky, rum or liqueur, as the case may be, but an imitation of these articles produced by adding artificial flavouring matters, generally of chemical origin, to plain alcohol. Genuine essential oils, such for example as oil of peppermint, oil of aniseed, oil of lemon and oil of bitter almonds, although used for flavouring alcohol for drinking purposes are not in any way objectionable, even though dissolved in alcohol and called essences, nor are such sub- stances as anethol, although used for the same purpose. What are objectionable however are the purely artificial mixtures used for making imitation liquors which are dis- honestly sold cis the genuine article. ALCOHOLIC LIQUORS 31 Probably however the time will come when any alcoholic liquor of the general nature of brandy, whisky, rum, etc., as the case may be, except possibly wine, can be legally so described, no matter from what materials it is made or how it is manufactured, just as in England at the present time any liquor of the general nature of beer may legally be sold as beer, even though it contains neither malt nor hops. Despite this latitude however the best quality beer is still made from malt and hops and will continue to be so made, and the best quality brandy, whisky, rum, etc, will always be made from the same materials and much in the same way as at present. At one time genuine whisky was made only in pot stills, patent stills being unknown, but now either pot stills or patent stills may be used. The only logical position seems to be to abolish all restrictions either on the nature of the materials employed or on the process of manufacture, leaving as safeguards the prohibitions that no harmful ingredients shall be used and that the description under which the liquor is sold shall neither be wrong nor misleading. Methods of Analysis of Potable Spirits. — The methods of analysis of potable spirits are well known and generally vary very little in different laboratories, excejDt in respect to the determination of higher alcohols. In the Government Analytical Laboratory, Cairo, these latter are determined colorimetrically. For brandy the method is the one employed in France, notably by the chemists of the Paris Municipal Laboratory, the standard used being iso-butyl alcohol. For whisky and rum the method is that of the English Government Laboratory, a mixed alcohol standard being- adopted. It is admitted that this colorimetric method does not rest upon the same scientific basis as the Allen -Marquardt method, but it presents considerable advantages over the latter for practical work and is in fact the only method possible where a large number of samples must be examined in a limited time, and it undoubtedly gives results of practical value which are quite sufficient for identification purposes. No analysis of alcoholic liquors, however, is complete 32 LEGAL CHEMISTRY without smelling and tasting, both of which are absolutely indispensable, since a non-genuine article may give analytical results which are quite satisfactory, the fraud being only apparent from the smell and taste. Wine. — Wine is the fermented juice of fresh grapes. The actual analysis of wine presents no great difficulty, but the interpretation of the results needs considerable experience, and without such experience no analyst should undertake to pass a judgment on the quality of a wine unless the adulteration is of a very gross character, such, for example, as the addition of artificial colouring matter. There is no legal standard for wine in England, but in wine-producing countries regulations governing the quality of wine generally exist, the addition of certain substances being allowed or allowed to a limited and specified extent and the addition of other substances being prohibited. The most common form of adulterating wine, and the most difficult of detection, is by simj^le dilution with water. Other frequent additions are alcohol, which however is allowed in some cases, sugar and artificial colouring matter. Wines however may be wholly fictitious and may be made from raisins (dried grapes) or from fruits other than the grape. Occasionally artificial essences are added to improve the flavour. One very common form of fraud is the substitution of inferior wines for those of better quality. Beer. — Beer is a fermented liquor, generally brewed from malt or from a mixture of malt and malt substitutes, and flavoured with hops or other bitter. In England both malt substitutes and hop substitutes may be employed and the former are largely used in con- junction with malt, but the latter are seldom used. In France barley malt must be used to an extent of at least fifty per cent, of the material employed and hop substi- tutes are not allowed. In Germany only malt and hops are allowed. Stout is a beer coloured and flavoured either by roasted malt or by burnt sugar. There is no legal standard in England for the composition of beer and hence any alcoholic liquor of the general nature ALCOHOLIC LIQUORS 33 of beer is entitled to be termed beer unless it can be proved not to conform to the generally accepted meaning of the term. A liquor, however, is not considered to be beer unless it contains more than two per cent, of proof spirit (1.2 per cent, of absolute alcohol by volume). This merely means that beer must contain alcohol, since anything with less than 1.2 per cent, of alcohol can hardly be considered an alcoholic liquor. Beer is rarely adulterated in England and, when it is adulterated, it is chiefly by dilution with water. Occasional prosecutions, however, have taken place for the presence of an amount of salt considered to be in excess of the normal. In Egypt beer is sometimes extensively adulterated, the principal addition being water, but caramel, colouring matter derived from carrots, and sugar, in addition to any used by the brewer, have all been found. Sometimes too a little sodium bicarbonate is added to neutralize acidity and, in some cases of dilution, carbon dioxide under pressure is intro- duced into the beer to revivify it. Fallacies Regarding Alcoholic Liquors. It is pojDularly supposed and frequently stated that alco- holic liquors are particularly liable to be grossly adulterated and drugged and that it is to the presence of narcotics that the bad effects of such liquor is due. The question of the addition of harmful ingredients to potable spirits was carefully investigated both by the Select Committee on British and Foreign Spirits (1891) and by the Royal Commission on Whisky and other Potable Sj)irits (1909) and neither of these bodies was able to obtain any evidence whatever of the addition of any substances injurious to health. A similar conclusion was arrived at from the examination of over 1,100 samples of alcoholic liquors in Canada. I A few samples of distilled spirits specially examined in India for the presence of alkaloids also gave negative results. 2 Aconite and datura are however » Bidl. Inl. Rev. DepL, Ottawa, 1891 and 1903. 2 Anahjst, 1904, 149. 4 34 LEGAL CHEMISTRY sometimes added to native made toddy in country districts in India. ^ Since the advent of a large number of British troops into Egypt consequent on the war, statements that certain alco- holic liquors contained harmful drugs have been very common. One complaint stated that men with many years of un- blemished service " dropped like logs after one or two drinks." In consequence of these complaints a number of samples of liquor have been specially examined from time to time for drugs, particularly alkaloids and hashish, and in no case has anything of the sort been found. Whenever the com- plaints themselves have been investigated it has been found that the amount of alcohol taken had been considerably understated. Thus a certain rum was complained of as being drugged, and it was stated that soldiers after drinking it and on going out of the bar into the cold air fell down insensible, but on enquiry it was found that the men had each drunk a tumbler and a half of the rum, apart from any water added and irrespective of any other liquor taken earlier in the day. In another case it was ascertained that the men had each drunk, at one bar alone, a mixture con- sisting of half a pint of red wine and a large portion of rum. Another common fallacy is that new spirits are specially deleterious. The Royal Commission investigated this matter also and stated that there was no evidence that age brought about any material change in the toxicity of spirits. In cases which concern the quality of alcoholic liquors the expert will almost certainly be asked whether samples, which have been proved to be adulterated, are drugged and also whether they are injurious to health. In view of the o])inions expressed by both the Select Committee and the Royal Commission, the reply must be in the negative unless some specific noxious ingredient has been found. Any specially ill effects are due as a rule to the excessive quantity consumed and this is frequently a result of the liquor being cheap. A usual characteristic too of cheap spirits is that ' Annual Reports of the Chemical Examiner's Department, Bengal, 1912, 1913 and 1914. ALCOHOLIC LIQUORS 35 they have very little flavour and hence a consumer who has possibly been accustomed to a more highly-flavoured article may not always realize that he is drinking comparatively strong alcohol. BOOKS OF REFERENCE. Report from the Select Committee on British and Foreign Spirits. London, 1891. Reprinted, 1908. Royal Commission on Whisky and other Potable Spirits. Lojidon, 1908 and 1909. Paper in Connection with the Establishment of Standards for Whisky in Western Australia. Perth, 1915. Chiniie Legale. R. de Forcrand. Paris, 1912. Bell's Sale of Food and Drugs Acts. C. F. Lloyd. London, 1910. Alcoholic Liquors and the Liquor Trade in Egypt. A. Lucas, F.I.C. Cairo, 1916. ANTIQUITIES The counterfeiting of antique objects is a very prevalent kind of fraud in the detection of which the chemist is some- times indispensable, and hence chemical evidence becomes necessary if the case is brought into Court, as such cases not infrequently are on account of the large sums of money involved. All manner of ancient things are forged, including docu- ments, furniture, pictures, copper and bronze articles, gold and silver objects, flint implements, coins and Egyptian antiquities. On one occasion a number of excellent modern bronze dies which had been used for counterfeiting ancient Roman and Greek coins were examined. Clay moulds of the Roman period have also been examined ; these are generally supposed to have been used or intended for use in counterfeiting though this has never been proved. Counterfeiting has become almost a fine art and is carried to such perfection that sometimes the expert who has made a lifelong study of such articles is puzzled, and then the ser- vices of a chemist may be requisitioned and not infrequently 3G LEGAL CHE:MISTRY chemical analysis will reveal the fraud, and it will be found that the article is not of the composition stated, or not of the composition it should be if it were genuine. Sometimes the chemist may be helpful in proving, not the falseness, but the genuineness of an article. The follow- ing is a case in point. During negotiations in connection with the purchase of a valuable ancient Egyptian knife having a flint blade and a gold handle, it was noticed that the cementing material which fastened the blade into the handle looked very fresh, and it seemed possible that, although both the blade and handle might be genuine, yet originally they might not have belonged to one another, but might have been put together in order to enhance the value of both. If this had been done, the work would almost certainly have been carried out in Europe or b}^ a European, as the native Egyptian forgery is generally very crude. Analysis of the material however showed that it was not a good quality plaster of Paris, such as would have been used in Europe or by a European, but that it corresponded in composition with a native Egyptian plaster and hence, from the point of view of the cementing material, no objection could be taken to the knife, which was eventuallj^ accepted as being genuine. As already mentioned, Egyptian antiquities are extensively forged, and in two public exhibitions of native industries, one held in Cairo and the other at Alexandria, there were stalls devoted to forged antiquities, the making of whicli in Egypt is a recognized and lucrative business : at Luxor a shop where forgeries are made and sold is among the places of interest visited by tourists, and Gourna near Luxor is a well-known centre for the manufacture of forged articles. In very early times the gold used in Egypt was not ]nu-ified in any way but was employed in the condition in which it occurs naturally, and since native Egyptian gold invariably contains silver, thisjuetal therefore is a constituent of ancient Egyptian gold articles. Five specimens of thin gold from tombs of the eighteenth Dynasty analysed contained from 1.9 per cent, to 20.5 per cent, of silver. Copper was entirely absent in one case but was present in the other four cases, ANTIQUITIES 37 the amount varying from 1.5 per cent, to 13.1 per cent. In two specimens of silver from the same tombs 8.4 per cent, and 8.7 per cent, respectively of gold was found : in both these cases copper was also present, the amount in the one instance in which it was determined quantitatively being 4.3 j)er cent. Berthelot i states that pure gold free from silver was first made and used in Egypt in the Persian era and therefore genuine gold articles of a date anterior to the Persian invasion can usually be recognized, though it should not be forgotten that gold was brought into Egypt from other countries and that nothing is known of the degree of purity of this gold. The analysis or microscopic examination of copper and bronze articles also sometimes provides a means of detecting modern imitations. A patina on such articles is no guarantee of age or genuineness since it can readily be produced artificially. Scarabs are perhaps forged to a greater extent than most Egyptian antiquities and even chemical analysis would not always detect the fraud, since genuine old materials are fre- quently employed, pieces of ancient pottery of no value being ground up, moulded, sometimes in a genuine old mould, and coated with genuine old glaze. The chemical analysis of an article such as a scarab however is not recommended, since any such analysis would be difficult, if not impossible, with- out defacing or destroying the specimen. The colours used by the ancient Egyptians as pigments were all mineral substances with the exception of black, which was carbon ; the reds and yellows were naturally occurring compounds of iron, the former being red ochre or haematite and the latter yellow ochre : the blues and greens were copper compounds. Analysis therefore might be very useful in detecting fraud. Cobalt has been reported as having b'een found in Egyptian pigments and glazes but, so far as is known, cobalt only occurs in Egypt in minute quantity and there is no evidence that it was ever worked. The colours employed in ancient Egypt for dyeing fabrics I Comptes Rendus, 1900, 131, 401, 467, tlii'oiigh J. Soc. Chem. Ind., 1900, 905. 38 LEGAL CHEMISTRY were of vegetable origin, the blue being indigo in at least some cases, and the presence of an aniline colour would neces- sarily indicate a modern imitation. Although the value of chemistry to archaeology might be considerable, very few archaeologists avail themselves of the service of the chemist, and hence a mistake like that made by one well-known Egyptologist, who described castor oil as honey, becomes possible. The oil, which was more than 3,000 years old, had undergone considerable alteration and in general appearance and consistency^ it did somewhat resemble honey, but a very simple analysis was sufficient to indicate its true nature. Chemical analysis might conceivably prove useful in connection with mummies, thus the cloth used by the ancient Egyptians for wrapping round the bodies of the dead was never cotton but invariably linen ^ and the preservative materials, although now often black and pitch-like in appear- ance, are as a rule resin or gum resin blackened by natural processes operating during thousands of years. Occasionally however wood pitch was employed but, although a very large number of specimens of black pitch-like material from human mummies, many of which have been described by eminent Egyptologists as pitch or bitumen, have been exam- ined, no single case of the occurrence of either has been found. = Coal tar pitch too is of course excluded since this material was unknown to the ancient Egyptians. BOOKS OF REFERENCE. Criminal Investigation. Hans Gross. Trans. Madras, 190(5. Ai-chaeology and Falso Antiquities. R. Munro. London. Forged Egyptian Antiquities. T. Q. Wakding. London, 1912. Preservative Materials used by the Ancient Egyptians in Embalming. A. Lucas, F.I.C. Cairo, 1911. The Use of Bitumen or Pitch by the Ancient Egjq:)tians in Mummi- ' This refers to the periods during which definite nuunniification was practised and not to later times. 2 The similar-looking material from the mummies of birds and animals has not been examined and may possibly be mineral jiitch or bitumen. ANTIQUITIES 39 fieation. A. Lucas, F.I.C, J. Egypt. Arch., Vol I, Part IV, October, 1914. The Preservation of Antiquities. F. Rathgen. Trans. G. A. and H. A. Auden. Cambridge, 1905. BLOOD STAINS As an aid in the detection of crime, the value of testing stains which look like blood, to ascertain whether they are blood or not, is well known. The tests applied are chemical, micro- scopical and spectroscopical.i Mere identification, however, is not of much use unless it can also be shown what the kind of blood is and whether or not it is human blood. This can only be done by means of a biological test, which possibly carries the work outside the domain of the chemist, more particularly if the serum has also to be prepared. There is no doubt however that the chemist, by reason of his training and experience in manipulation and his skill in testing and general laboratory practice, is well qualified to undertake blood testing even though such work may not be strictly chemical. It may be mentioned too that the " detection of blood stains " is among the subjects required to be known by all candidates presenting themselves for the examination for the Associateship of the Institute of Chemistry. Blood testing in legal cases should only be undertaken by those having considerable experience of the work as issues of life and death frequently depend upon the results. Since the author's duties do not include blood testing this subject will be dealt with very briefly. The best preliminary test for blood is that with benzidine which is much to be preferred to guiacum. The re-agent consists of a saturated solution of benzidine in glacial acetic acid to which hydrogen peroxide is added and, like guiacum, it gives a blue colour with blood. The various factors involved ' It is not intended to suggest that the microscope and spectro- scope are outside the boundaries of chemistry, for such is not the case any more than is a thermometer, the microscope being a necessary appurtenance of the chemist, and the spectroscope an essentially chemical instrument. 40 LEGAL CHEMISTRY in this test have been investigated,' and it has been found that the sensitiv^eness depends upon the relative concen- tration of the benzidine, acetic acid and hydrogen peroxide, and that excess of both acetic acid and hydrogen peroxide must be avoided. The latter also must be perfectly pure and free from acidity. At its best however the benzidine re-action can only be regarded as a sorting test showing when blood is absent but not proving its presence with certainty and therefore it always needs confirmation by other tests, A blue colour apjDearing at once is however strong pre- sumptive evidence of the f)resence of blood, but any blue coloration not given immediately must be disregarded. An excellent method of carrying out the haemin test for blood is that described by Beam and Freak, = BOOKS OF REFERENCE. Taylor's Principles and Practice of Medical Jiu-isprudence. F. J. Smith. London, 1910. Allen's Commercial Organic Analysis. Davies cfc Sadder. London, 1914. Blood Stains, by Lieut. -Col. W. D. Sutherland, in Lyon's Medical Jurisprudence for India. L. A. Waddell. Calcutta, 1914. BUILDING MATERIALS The quality of building materials is a matter which often gives rise to litigation, and hence the services of the chemist may be required in this connection. In the case of such materials as stone, brick, cement and hydraulic lime, both chemical and phj'sical tests are employed. If the chemical tests are carefully carried out the results are not OYiGii to much criticism, but the results of the physical tests, being largely influenced by the manner in which the tests are performed, leave considerable room for dispute, and hence it behoves the expert to make sure that his testing ' J. Biol. Chern., 1914, 448-457, through J. Chem. Soc, 1915, 11, IHi. = Biochem. J., Vul. IX, No. 1, March, 1915. BUILDING MATERIALS 41 machines are up to date and in good working order and that the tests are made in accordance with standard methods, if such exist, or if there is no standard method, then in some generally recognized manner. Thus the results for the crushing test for stones and bricks vary very much with the size and shape of the test pieces used and also depend upon the nature of the material between which they are placed for crushing, and also, in the case of stone, whether or not the blocks are properly dressed and the sides parallel and, in the case of bricks, whether they are embedded in mortar or plaster in order to obtain perfectly flat surfaces or are left without any such precaution. The results of the test for tensile strength of cement, too, vary considerably with the manner in which and the temperature at which the briquettes are made and also with the temperature at which they are kej^t. Briquettes of neat cement also decrease in tensile strength if left to dry before they are tested after having been taken out of the water. A number of interesting cases concerning building materials have been investigated and will now be described. Several of these cases were connected with the disinte- gration of reinforced concrete due to the rusting of thfe iron. As iron cannot rust without the presence of water, the origin of the water should always be sought, since this is generally the key of the problem, other necessary or active agents such as oxygen, carbon dioxide, impurities in the iron and electrolytes in the water being always present. Sometimes, in the absence of an examination of the damage by a competent chemist, corrosion of iron, whether in reinforced concrete or not, is wrongly attributed to electrolysis by stray currents, which is easily invoked and difhcult to disprove, but this explanation should never be given unless there is direct evidence for it and an absence of other adequate causes. The various cases were as follows : — 1. The reinforced concrete on the inner sides of the roofs of a number of sheds forming an animal quarantine station became badly corroded. The sheds were situated near the sea-shore at Alexandria, and the damage manifested 42 LEGAL CHEMISTRY itself some seven j-ears after the buildings were erected. A chemical examination of the materials used for the concrete showed that the aggregate consisted of broken limestone and that the sand was calcareous and not siliceous. ^ Both these materials being permeable, and therefore easily pene- trated by water, and the buildings being at Alexandria, where in the winter there is a certain amount of rain, and also near the sea, where there is spray and mist, all the elements of disaster were present. Both the limestone and the sand, being of local origin (the limestone being obtained from quarries near the coast and the sand from the sea-shore) contained salt, which is hygroscopic and absorbs and retains water and therefore aids corrosion. 2. In this case the iron rods in the foundation of a building became corroded, the corrosion being noticed about sixteen years after the building was erected. Here again the damage was caused by the use of permeable and- unsatisfactory material, the aggregate being formed of broken tiles, bricks and limestone and the sand being calcareous. In this case too salt was also present and doubtless accelerated the mischief. 3. In this case the iron rods in a pillar on a balcony of a house near Cairo corroded, and also a girder in the ceiling of a semi-basement room in the same house. Being near Cairo, where there is very little rain, the building was not exposed to much wet. The materials and workmanship were good. The cause of the damage to the balcony was not discovered but, in the case of the girder, it was suggested that possibly the room had been kept closed and, being partly underground and without much natural ventilation, there might not have been sufficient opportunity for the moisture originally present in the concrete to dry out and that this had attacked the iron of the girder.* 4. Here the iron rods on the inner side of the roof of a water reservoir corroded badly. This was probably due to the fact that the iron was too near the surface, the layer of concrete not being thick enough to afford adequate pro- ' A large part of the sand in the neighbourhood of Alexandria, both on the desert and on the sea-shore, is calcareous. • In this connection see case No. 6. BUILDING MATERIALS 43 tection. Except in the roof the iron was deeper seated and hence better protected^ The water, without which the corrosion could not have taken place, was that which evaporated from the reservoir and condensed on the surface of the concrete. Two cases, somewhat similar to the last four, were concerned with corrosion of iron girders embedded in concrete. 5. In this case several of the iron girders in the roof of an important building at Alexandria rusted and caused the collapse of part of the roof. The girders were embedded in concrete. As in several of the instances already mentioned, the damage was due to the use of permeable materials, the aggregate of the concrete consisting of broken limestone with a little brick, and the sand being calcareous. Being situated at Alexandria the building was subjected to a certain amount of rain in the winter and the roof, which was flat and covered with asphalt, had at one time been allowed to fall into a state of bad repair and hence the rain had been able to penetrate and had caused the damage, which how- ever did not manifest itself until sometime afterwards when the roof had been repaired. A little salt was present in the concrete, and would aid the corrosion of the iron. 6. This also was a case of the corrosion of iron girders. The girders were in the ceiling of a room on the top floor of a large and comparatively new building at Alexandria and the flanges of all the girders were corroded. The roof was intact and no rain had gained access. Moreover, the damage occurred in one room only out of a large number built at the same time and of similar materials. The only difference which could be traced between this one room and many of the others was that the ceiling of this room, as also of two others (one immediately adjoining), had been painted with several coats of a good enamel paint, whereas the other ceilings were simply plastered. The water primarily respon- sible for the mischief was probably that originally present when the work was done, and the impermeable asphalt of the roof above and the impermeable paint of the ceiling below had prevented the excess water from evaporating, or from evaporating quickly enough, and hence sufficient water had 44 LEGAL CHEMISTRY remained to rust the iron. The thin layer of plaster beneath the paint still smelled damp and rflusty although four and a half years had elapsed since the work was finished. The fact that there was no corrosion in the other two rooms having similar painted ceilings was accounted for by assuming that in these cases the concrete had been allowed time to dry before the paint was applied. In one of these •cases, namely that of the room adjoining the one in which there was damage, there was a much less depth of concrete, and hence drying would be quicker. 7. This was an investigation to ascertain if possible the approximate date of construction of some windows in the side of a house overlooking land belonging to the Munici- pality of Alexandria, the owner of the house having become entitled to certain rights of light if it could be proved that the windows had existed for more than fifteen years. In the case of two of the windows the woodwork was of a very different pattern, of much better quality and manifestly much newer than the rest, and these two windows were un- doubtedly less than fifteen years old. In the case of three other windows the evidence of their age was not conclusive and it could not be proved that they were less than fifteen years old. Two of these windows belonged to one room and, with the excejition of two small fanlights, one over each of the two doors, they were the only means of lighting the room. The value of this fact however was discounted by the further fact that there was evidence that another window had previously existed and had been blocked uj). Four other windows were certainly the same age as the house, which was admittedly much more than fifteen years old. These windows were the only means of lighting the rooms in which they were situated and in two cases there were also small inner rooms which derived their only light from the same windows. The woodwork was old and there were no old nail holes or other evidence that it was old wood which had been re-used. A very significant fact was the presence of horizontal timber bonds for strengthening purposes in the wall at both sides of each of the four windows. The wood of these bonds was very dry and old and the pieces at the two opposite sides of each ^^•indow were at different BUILDING MATERIALS 45 levels and manifestly, therefore, they had not been longer pieces which had been cut through to make room for the windows but, in their existing condition, they must have formed part of the original wall. The problem was rendered difficult by the fact that the walls were jDlastered both inside and out, the j)laster having been repaired in places, and the woodwork repeatedly painted. A large number of analyses of the mortar and plaster, parti- cularly of that immediately around the windows, was found necessary. Portland cement is a material frequently adulterated in Egypt by the addition or substitution of hydraulic lime or of cement of an inferior kind, the mixture being some- times coloured with carbon so that it may more closely resemble the genuine article. In one instance a mixture of ordinary lime and volcanic earth (pozzolana or Santorin earth) coloured with carbon was supplied, and in another instance fifty per cent, of very finely ground sand had been added to the cement. As a rule when such questions come before the Court neither the methods nor the results of the analysis are questioned, but only the interpretation of the results, though sometimes the point of whether or not the samples are truly representative is raised. In one case how- ever the chemist for the defence contended that, in order to obtain a true conception of the quality of the cement, the moisture and carbon dioxide absorbed during storage should be driven off by calcination before the analysis was made. This was not agreed to, more particularJy as the sample in question contained more carbonate than could be accounted for by absorption of carbon dioxide. Disintegration of Building Stones in Egypt. A very marked disintegration of building stones is a common occurrence in Egypt, one of the most noticeable features of which is that it occurs most frequently within a zone situated between ground level and a distance of about a metre or a metre and a half above ground level and that it is generally accompanied by a very marked white incrus- tation or efflorescence. This efflorescence, which is the 46 LEGAL CHEiMISTRY origin of the disintegration, and which forms under the surface layers of the stone causing these to flake and peel ofif, consists as a rule essentially of sodium chloride, but sometimes is a mixture of sodium chloride and sodium sulphate and occa- sionally contains small proportions of other salts such as sodium carbonate, sodium nitrate and potassium nitrate. The damage is peculiar to the climate and, though doubtless existing in other countries where similar climatic conditions prevail, it is absolutely unknown and would be impossible in countries where there is much rain. The salts as a rule are derived from the ground, but occasionally come from the stone itself. The lack of an efficient damp course and the use of inferior stone are the principal contributory causes. Such cases may give rise to legal action and hence may call for chemical investigation. BOOK OF REFERENCE. Disintegration and Preservation of Building Stones in Egypt. A. Lucas, F.I.C. Cairo, 1915. BULLETS AND OTHER PROJECTILES FOR FIREARMS Bullets, with which may be included slugs and small shot, differ in composition according to the purpose for which they are required, particularly if made by different manu- facturers or in different countries, hence in a case of murder, attempted murder or wounding by shooting, tlie chemical analj'sis of the projectile may provide very valuable evidence. Bullets are generally either of lead or of lead coated or tipped with some other material. Lead bullets usually contain small proportions of antimony or tin or both, added for hardening purposes in order to give greater penetration. Ten per cent, of antimony is stated to be the usual admixture. Ordinarily however bullets consist of a lead core (either soft or hardened) coated Avith some harder metal such as copper, cupro-nickel, steel or steel plated with cu})ro-nickel or some- times they are of lead tijiped with another metal such as BULLETS AND OTHER PROJECTILES 47 aluminium. Pure aluminium has also been employed for bullets as well as alloys of this metal with tungsten and magnesium and solid copper bullets have also been used. During the war of 1914-18 rifle bullets of sj)ecial material and construction were employed for armour piercing and incendiary purposes. Slugs are of lead generally hardened with antimony or tin or both. I Small shot practically always consists of lead to which a small proportion of arsenic (variously stated to be from one-tenth per cent, to five per cent.) is added for the purpose of enabling the lead to assume the spherical shape when the molten metal is cooled by being dropped into water. On one occasion some small shot examined was found to be iron, it was coated with graphite, was very irregular in shape and varied in size in the same cartridge. The following cases in which the chemical analysis of a projectile has proved useful may be quoted. 1. In this case some white metal adhering to a piece of lead with which a man had been shot, but fortunately not wounded, was found not to be nickel, as was at first supposed, and which would have indicated a nickel coated bullet, but silver from a cigarette case which had been penetrated. A night watchman suspected of the crime escaped conviction because the projectile did not agree in composition with the slugs in the cartridges with which he was supplied. 2. In a second case a man, who was suspected of wounding another by shooting, escaped conviction because the shot from a cartridge seized in his house was found on chemical analysis to differ in composition from the shot extracted from the wounded man, the former containing a compara- tively large amount of tin and the latter containing no tin but a trace of antimony. 3. In a somewhat similar case to the one just mentioned a night watchman shot at some unknown persons suspected to be thieves who, however, all escaped. In the morning, I In slugs from twelve diiferent cartridges analysed the antimony varied from 0'3 per cqfit. to 0*9 per cent, and the tin from nil to 0'6 per cent. 48 LEGAL CHEMLSTRY blood was found on the ground and subsequently a man was arrested with a shot wound in his leg for which he failed to give any satisfactory explanation. Analysis, however, proved that the lead extracted from the wound did not agree in composition with the slugs in the watchman's cartridges and consequently the man was released. The impurities present in the lead were the same in each case and consisted chiefly of antimony, but the shot from the wound contained much less antimony than the slugs. As a rule in shooting cases the amount of material avail- able for analysis is very small, since not only is the total amount small, but of this as large a quantity as possible must be reserved for further analysis or for production in Court. In such cases where a comparison between several different samples of lead only is required the following method ^ will be found the best. Take half a gram of each sample in a finely divided condition, put into separate small conical flasks and add to each five grams of ammonium sulphate - and ten cubic centimetres of strong sulphuric acid and heat for about ten minutes. Although the bulk of liquid is small there is no fear of the flask breaking. The lead is fully precipitated as sulphate and is quite white and free from impurities, and any arsenic, antimony and tin present remain in solution. Cool and add to each flask twenty-five cubic centimetres of a ten per cent, solution of tartaric acid. This prevents the antimonj^ and tin from being precipitated by the water, which, if it were not added with the tartaric acid, would have to be added to dilute the solution before filtration. Shake well and boil for five minutes in order to granulate the sulphate of lead. Filter into Nessler tubes (it is not necessary to use asbestos or a Gooch filter) and wash with dilute sulphuric acid (ten per cent, solution) using a minimum quantity and approximately the same amount in each case. To the filtrates add dilute sodium sulphide solution acidified with hydrochloric acid (a convenient substitute for sulphur- « Due to W. B. rollanl, B.A., Government Analytical Laboratory, Cairo. = If more than about five per cent, of tin i.s present the ammonium sulphate shoulil be omitted. BUIXETS AND OTIIP^R PROJF.CTII.ES 49 etted hydrogen). Make up to the same volume (50 c.c.) with water in each case, stir well with a glass rod and compare. The contents of the tubes should be transferred to glass stoppered bottles and preserved for presentation in Court. If tall narrow bottles of clear glass are used, the different amounts, colours and general appearance of the various precipitates are very marked and demonstrate the results in a manner that no mere recital of percentages can possibly do. If required, this method may be made quantitative, in which case, however, the filtration should be through asbestos, using a Gooch crucible. The anti- mony and tin are separated in the usual way and arsenic, if present, is determined in a sejoarate portion of the sample. Not only may the analysis of the jorojectile prove of value but the nature of the wads, if any, may also provide valuable information. Thus wads from different cartridges differ very much in thickness, in the manner in which the component parts, generally cardboard and felt, are put together and in the colour of the cardboard and of the thin layer of paper which covers it. Sometimes too, the cardboard which comes into immediate contact with the shot bears indentations and marks made by the pellets, from which the number corresponding to the area of the wad, and hence their size, can be determined. Occasionally the paper label from the end of the cartridge, which bears the description of the powder and the size of the shot, is found intact. This question of the size of the shot is sometimes of considerable importance, as for example in the Monson trial. In this case there were two guns involved, one a 12-bore gun with which No. 5 shot was used and the other a 20-bore gun with which No. 6 shot was used, and a great deal depended upon from which of the two guns the fatal shot had been fired. Four pellets were found in the brain of the victim, and the prosecution contended that the weight of these pellets established the fact that death had been caused by a discharge from the 12-bore gun loaded with No. 5 shot. It was also proved that a bloodstained wad found near the body was for a 12-bore gun. In view of the possible importance of the size and weight 5 50 LEGAL CHEMISTRY of jiellets from different cartridges the following few deter- minations are recorded — Number of Shot .... Bore of Gun Number of Cartridges examined Weight of Shot in Cartridge . ■ Weight of Shot in Cartridge . Number of Pellets in Cartridge Number of Pellets in Cartridge Diameter of Pellets Diameter of Pellets Keniington. Eley. 10 10 12 12 ry 6 Min. .31 ■ 7 grams 3 1 ■ .5 granis Max. 32 • 8 grams 32 • 2 grams Min. 1,377 983 Max. 1,949 1,097 Min. 0-90 mms. 1 ■ 72 mms. Max. 3 • 50 mms. 1 • 75 mms. In the Remington cartridges pellets of different sizes occurred in the same cartridge. From the above facts it is evident that not only does the number of pellets sometimes differ considerably in cart- ridges of the same make, but that the size of the jDcllets may vary in the same cartridge, and therefore great care is re- quired in making any general deductions from the size and weight of isolated pellets. Slugs from cartridges, such as are supplied to the native watchmen in Egypt, have also been examined. One make of cartridge contained seven slugs which varied in weight from 1.71 grams to 1.78 grams each and another make con- tained eleven slugs with weights varying from 1.78 grams to 1.83 grams each. The lead in both instances Avas hardened with antimony but the proportion of antimony present in one case was about twice that in the other. It is stated that on a lead bullet which has passed through clothing it is sometimes possible to see an imprint of the texture of the cloth first penetrated. ^ When dealing with cartridges, the bullet or pellets, the charge, the wads and the case should all be separately weighed and examined. The easiest way of extracting a bullet from a cartridge is to put the bullet point downwards, and sur- rounded by paper to protect it from injury, in a small vice or clamp and to work the case gently from side to side until it is felt that the bullet is quite loose, when it is removed from the vice and extracted with the fingers. To examine ' Manuel de Police Scientifique, Vol. I. R. A. Reiss, Lausanne, 1911. BULLETS AND OTHER PROJECTILES 51 a shot gun cartridge this should be laid on its side and cut through about the centre with a sharp knife, when the charge will be found in one half and the pellets in the other, each kept in place by a wad. Sometimes the expert may be asked to express an opinion as to the nature of the projectile, whether for instance it is a rifle bullet, a revolver bullet or a slug. No opinion how- ever should be given unless the evidence is very definite and unless the expert has had previous experience. As examples of the difficulties in such cases it may be mentioned that the envelope of a coated bullet may sometimes be entirely stripped off and detached from the lead core and that a square slug may become so distorted on impact as to make an almost round hole and when found may be oval or round with definite " mushrooming " and may show little or no evidence of ever having been square. ^ Such problems, as also those concerning the distance or direction from which a firearm has been fired, should be left to sportsmen or gunsmiths or others having considerable experience in these matters. For an example of how experts may differ in such cases, the trial of A. J. Monson, which has already been alluded to, should be consulted. BOOKS OF REFERENCE. Criminal Investigation. Hans Gross. Trans. Madras, 1906. Notable Scottish Trials. A. J. Monson, Edited by J. W. More, CLOTHING There are few articles which afford so many clues to the personality, habits and history of the owner as clothes and few articles better repay careful examination. Clothes may be considered under many aspects, as for example in relation to the material of which they are made I The presence of straight lines or slight ridges, which are some- times all that remain of what have been the edges or corners of the slug, should be specially looked for. 52 LEGAL CHEMISTRY or in connection with stains, marks, or dust wliicli may be found upon them and these aspects will be dealt with later, but there are also other features, too numerous to specify, which should be taken into account and each case must be considered as a sej)arate and special study. The following examples will make this clear. 1. In this case a waistcoat was submitted with a request that it might be examined for clues concerning the immediate history of the owner, who was discovered under suspicious circumstances near the Suez Canal during the war of 1914-18. The following facts, which appeared significant, were found : The waistcoat was clean, in good condition, and looked almost new. The bone button of an inner pocket bore a name which was probably that of the tailor and the address Batavia. One of the pieces of cloth of which the lining was formed bore a portion only of a stain (probably due to perspiration) which ceased abruptly at a seam. The waistcoat was impregnated, both at the toji and bottom, with chlorides, sulphates and other salts character- istic of sea water. I Each pocket contained a small amount of very fine quartz sand with rounded grains of practically uniform size, which closely resembled dune sand. The deductions from the above facts were as follows : — 1. The owner of the waistcoat had bought a ready-made suit of clothes in Batavia. The stain proved that the lining had been used before and the fact of the waistcoat being almost new pointed to ready-made clothes in which some old lining had been used, rather than to a second-hand suit. 2. The man had travelled to Egypt in a Dutch steamer. Dutch steamers were then passing through the Suez Canal and were the only ones that called at Batavia. 3. The man had left the steamer surreptitiously while ' These naturally weio not visible, but portions of the waistcoat were soaked in distilled water, and the solutions thus obtained ex- amined chemically. CLOTHING 53 it was passing through the Canal and had swum to the shore. Entire submersion, which pointed to swimming, was indi- cated by the fact that even the top of the waistcoat showed evidence of having been wetted with salt water, and it followed therefore that the mode of leaving the steamer was unusual and probably surreptitious. 4. The man had landed from the Canal at a place where there were sand dunes. This followed from the nature of the sand found in the pockets. The above conclusions were subsequently proved to be correct. 2. The remains of a man in European clothing were found buried on some unoccupied land, and it was hoped that some clue to his identity might be discovered from an exam'nation of the clothes. The following facts were noted : — The coat and waistcoat were alike and were of thick, striped, brown tweed. Parts of some bone buttons still remained, but these did not bear any tailor's name or other inscription. The trousers did not match the coat and waistcoat, but were of thinner material, though almost of the same colour and pattern. There were six metal buttons left on the trousers, all of which were very corroded but, when cleaned, the name and address of a tailor in Duke Street, Portland Place, London, were legible. Most of the stitching of the clothes had perished, leaving the garments in separate pieces : the lining was much decayed and the pockets were missing. The undervest, of which only a part remained, was of cotton. The shirt, of which only a part remained, was of coloured cotton, the predominant colour being green, but there were brown stripes which seemed to have been red originally. The front was pleated and was ornamented with cross stitches in red. The one sock was of thick red wool and in fairly good condition. There was a part of a good quality handkerchief, which, however, bore no name. 54 LEGAL CHEMISTRY Collar, boots, and hat were missing, but no very careful search had been made for these or other articles. The conclusions drawn from the facts were : — The man was . most probably a European but not an Englishman, and not the man for whom the clothes had been originally made, since Englishmen do not as a rule wear green shirts with coloured stripes and pleated fronts orna- mented with red stitches, neither is such a shirt worn by one who obtains his clothes from a West-end London tailor. ^ The man was probabl}'^ not destitute although the clothes were second-hand, since they were in good condition and included a good handkerchief. The one sock may be taken as presumptive evidence that at the time of his death the man was wearing two socks and also boots, as to wear only one sock, or socks without boots, would be most unusual. Naturally only the articles forwarded could be examined and, so far as was ascertained, no systematic search had been made for others. One very noticeable feature in this case was that the articles made of cotton, such as the shirt and vest, the lining of the clothes and the thread used for stitching, had perished to a much greater extent than the articles composed of wool, like the clothes and the sock. The state of preservation of clothes and other buried articles depends not only on the nature of the clothes or articles themselves, but also upon the nature of the soil in which they are buried and the depth at which burial has taken place, and no general rule can be laid do^v^l. Thus, linen wrapping cloth from Egyptian mummies several thousands of years old is still frequentlj^ in an excellent state of preser- vation, while in other instances it is in a very friable con- dition or has entirely perished. During the Archa}ological Survey of Nubia the author had an opportunity of seeing most of the excavations near Aswan and was particularly struck by the variation in the state of preservation, not only of the bodies, but also of the other perishable objects found I An Englisliman who had lived with poo]ilo of other nationahtics for many years, or wlio had married a non-EngUsh wife, might con- ceivably wear such a shirt. CLOTHING 55 with them. These burials are fully described in the published reports. I In the Predynastic graves, which were at least 6000 years old, the body was frequently wrapped in goatskin, and often was lying upon and covered with matting of coarse fibre or twigs, and the clothes, if any, generally consisted of a short leather kilt or loincloth. In a few cases linen was found. The wrappings were frequently in a very poor con- dition and sometimes only a few small pieces were left. In the early Dynastic and Old Middle Empire graves loose linen wrappings, goatskin and matting were usual. In an early Christian cemetery on the island of Biga near Aswan, which probably dated from between the fourth and seventh centuries a.d., more than five hundred bodies were exhumed. All were wrapped in coarse white cloth, but many were also wearing clothes, which generally consisted of a white shirt, and in some instances of two or even three such shirts, but which included in one case a pair of drawers, in another case a coat (kuftan), in another case a pair of socks, and in several other cases shoes or boots. Unfortunately no critical examination of the material of the clothes was made ; the archaeologist however states in one instance that a wrapping consisted of wool. In the " Report on the Human Remains," Professor Elliot Smith writes with reference to more than two thousand bodies found on the island of Hesa, near Aswan. " In the majority of cases the tissues were preserved in a most wonder- ful manner, so that not only the skin and hair, but every organ, vessel and nerve were retained, and it was possible to perform a necropsy on these people fifteen centuries after their death." These bodies had been sprinkled with coarse salt but were not mummified in any way. In the case of the Predynastic and other bodies, dating from a period before mummification was practised, the pre- ' The Arch. Survey of Nvibia. Report for 1907-8, vol. i. G. A. Reisner, Cairo, 1910. Report for 1907-8, vol. ii. G. Elliot Smith, M.D., F.R.S., and F. Wood Jones, M.B., B.Sc, Cairo, 1910. Report for 1908-9. C. M. Firth, Cairo, 1912. Report for 1909-10. C. M. Firth, Cairo, 1915. 56 I>EGAL CHEMISTRY servation of the body was merely a desiccation and resulted from the burial without coffins in shallow graves in hot, dry and porous sand, thus allowing heat to gain access and the moisture from the body to escape. There was also an almost complete absence of rain and subsoil water. The reason why many bodies of later periods, which were buried in deeper graves, have not been nearly so well pre- served as some of the earlier bodies is because the surface heat was excluded and the communication with the outer air was so slight that the body moisture was prevented from escaping. In many cases too the graves were so deep as to be in a zone always damp and even in some instances in a zone subject to periodical flooding. 3. In one of the cases mentioned under the subject of Stains and Marks, a gallabia ^ was found tied round the neck of the murdered man whose throat had been cut, probably to soak up the blood, and a small piece which had been torn from this was near the body. The pattern of the piece of fabric was not only identical with that of the gallabia, but the place from which it had been torn was plainly visible. The nature of the pattern, which consisted of circles, indi- cated that the garment had probably belonged to a woman or girl, since men's gallabias are plain or striped and never have patterns of circles, spots or flowers,- while women's gallabias, unless plain, possess these patterns and are seldom, if ever, strijied. The gallabia had also a pleat down each side of the upper part of the front, which again indicated a woman's or child's dress, and was very much torn at the front and had a patch of different material inserted from inside in order to mend one of the torn places. None of the foregoing facts proved of much value in this particular case, but it is conceivable that such indications might have been of considerable use, and such points should always be carefully observed and recorded. BOOK OF REFERENCE. Criminal Investigation. Hans Gross. Trans. Madras, 1906. ' Loose outer garment worn by both men and women of tlie poorer classes in Egypt. ■ The autlior lias only seen one exception whieli was tliat of a gallabia worn by a boy, which had a pattern consisting of o\als. COUNTERFEIT COINS 57 COUNTERFEIT COINS The examination of counterfeit coins, although not wholly chemical, has a very imjjortant chemical aspect, as it is generally necessary to determine the weight, specific gravity and composition of the suspected coins. Counterfeit coins are essentially of two kinds, cast and struck, the former being those made in moulds and the latter those made by means of dies. There is, however, a third way in which counterfeit coins might be made, namely, by means of the electrotype process, a method frequently employed for reproducing rare coins for museum purposes, but this method is seldom used by false coiners anywhere and never in Egypt. Occasionally counterfeit coins are cast and then silvered or gilt but examples of this are rarely met with in Egypt and only a few such cases have been seen, one of which was of counterfeit English sovereigns which were cast in lead and then gilt, the imitation being very crude. There have been several instances in Egypt of the passing as genuine coins of the imitation sovereigns made in England and sold at one time in the streets of London at a penny each. These, which are of the same size as the sovereign, though much lighter in weight, are of copper gilt and, since they are struck and not cast, the design is good and sharp ; they are also milled. As made originally these imitation coins are provided with a small ring at the top which is easily removed, but evidence of this is left. For obvious reasons, any detailed description of the manner in which counterfeit coins are made will be omitted, though a few general particulars may usefully be given. Cast coins are made in one operation by casting the metal in moulds prepared by taking impressions of genuine coins in suitable material such as plaster of Paris, clay, moulding sand or sometimes copper. The " runner " ^ is then removed I The thin rod remaining attached to the coin where the metal has entered the mould. Any vents made for the escape of air would produce similar, though thinner rods, but although the author has examined a very large niuiiber of coinage moulds, he has never yet seen any provided with special air vents. 58 LEGAL CHEMISTRY and the edge of the coin touched up with a file. Cast coins are generally much poorer imitations than struck coins and hence are more easily detected. A really first-class casting, however, with good milling, which fortunately is rarely met with, is very difficult to detect, more especially if it is worn, since even the smallest details of the design are correct. The surface of a cast coin is frequently pitted and uneven, the edges of the lettering and design are rounded instead of being sharp, there are little projections of metal where the lines should be straight and, in that section of the circumference from which the "runner" has been removed, the milling is irregular or defective and often shows evidence of having been made or adjusted with a file. Sometimes, however, the runner is so skilfully taken off and the milling so cleverly adjusted that, if the casting has been well done, it is difficult to say whether the coin has been cast or struck. A large proportion of the counterfeit coins made in Egypt are struck and many are excellent imitations. To make struck coins at least two separate operations are required, first the punching of circular pieces of metal of the correct size and weight from a sheet or strip, and secondly the impressing on these " blanks " the design of the coin. This latter is done from dies, the pressure being applied by means of a press. To produce the milling a steel collar, which is milled inside, fits round the dies. Sometimes, however, other devices are employed for the milling, such as pressing the blanks against milled wheels. The dies, which are of steel, are usually engraved, but may be cast and then touched up by an engraver. In the case of engraved dies, which necessarily take considerable time and skill to prepare, the counterfeiter sometimes follows the practice of the mints and only employs the original die as a means of obtaining secondary dies, and it is these latter, which can readily be duj^licated when broken or worn, which are actually employed for striking the coins. These secondary dies naturally all exhibit the same features and any slight peculiarity or defect existing in the original is reproduced in the copies. Struck counterfeit coins are often vcrv well executed, COUNTERFEIT COINS 59 and their detection is by no means always an easy matter, but one \Ahich requires considerable experience, since the weight, size, specific gravity, milling and composition may all be good, and only a careful comparison of the smaller details of the design with those of a genuine coin enables the deception to be discovered. A counterfeit coin is less easily detected when it is worn or when it simulates a worn coin. When examining coins, the most important points to which attention should be directed are first the details of the design and the manner in which the design has been executed, that is to say the quality of the workmanship, and secondly the milling, and a careful inspection with a lens and a careful comparison with a genuine coin are essential. The examination of the milling of a coin should include the determination of the number of ridges. These can best be counted by colouring the edge of the coin by means of a pad moistened with aniline ink, carefully removing the colour from one of the ridges, and then taldng the impression of the circumference of the coin on paper, and counting the number of lines made by the ridges, using the blank spaces caused by the removal of the colour from one of the ridges as the starting and finishing points, the number of ridges on the coin being of course the number of lines counted plus one. It should not be forgotten however that the diameter of genuine coins, and hence the number of ridges, sometimes varies with different issues of coins of the same denomi- nation from the same mint, and that the number of ridges may also vary with coins of the same denomination from different mints although the diameter of the coins may be the same. Both the weight and specific gravity of suspected coins are useful indications, especially the latter, and should always be determined, the weight of course being necessarily ascer- tained when taking the specific gravity. ^ Any excess of weight, however slight, above the legal limits, is a certain ' For the deterniiiiation of the specific gravity a httle basket made from fine platinum wire in which to suspend the coin ^^•hen weighing it in water Mall be found xiseful. 60 LEGAL CHEMISTRY proof that the coin is counterfeit ; a deficiency in weight may be due to the coin being worn. The density of coins composed of the same alloy and from the same mint is only constant for coins of the same size, and it varies inversely as the size of the coin, the smaller the coin, the greater being the density. The explanation of this is that the blow required for imj)ressing the design on the coin acts on a smaller area and on a thinner piece of metal in the case of the smaller coins, and hence produces a greater effect. The determination of the hardness of a coin, although possibly of some use to the person who tests a coin by biting it, is not of much assistance in any scientific examination. The "ring"' of a coin also is of very little value, since many counterfeit coins ring well, while genuine coins, if cracked, ring badly. Counterfeit coins should always be carefully examined for slight flaws and marks, since these if present on a number of different coins prove that all have been made in the same mould or with the same dies, or with dies made from the same punch or matrix, and so may enable the police to trace coins passed in different places to one central factory. This has been helpful on many occasions. Thus in several cases it has been possible to trace cast coins seized with different persons to the same source, because all the coins had the same defects and had manifestly been made in the same mould. In one important coining case, which had ramifications in different parts of the country, and in con- nection with which about forty persons were condemned, struck coins from places far apart all bore evidence in the details of the design, that the}'- had been made either from the same dies or from dies made from the same punch or matrix, and in many instances they had certainly been made from the same dies, since a flaw due to a crack in one of the dies occurred in the same position on each of the coins. Photographic enlargements are very helpful for attaching to the report, or for presentation in Court, as they enable similarities or differences to be readily demonstrated. The difficulty in successfully photographing coins is due to the low relief of the design and tlie consequent absence of contrast COUNTERFEIT COINS 61 in light and shade. This, however, may be overcome by arranging the coin so that it receives a strong light from one side, the direction of the light being parallel to the face of the coin. Prints are best made on bromide or similar paper. A simple and effective method of photographing coins is mentioned by Guebhard.i This consists in very slightly fogging, by the briefest possible exposure, an ordinary photo- graphic plate, j)l^cing this in a dish already containing sufficient developer to cover it, then putting the coins directly on to the sensitized surface of the plate and allowing develop- ment to proceed. After the lapse of a few minutes the plate is taken out and fixed in the usual way. All the operations, except of course the preliminary fogging, are done in a dark room. In connection with counterfeit coins, it is sometimes useful to mark on a map the places where particular kinds of coins have been passed, and the number of coins from each place. This may show the centre of distribution and so indicate a particular district in which special search can profitably be made. The services of a chemist are required not only for the examination of counterfeit coins, but also for the analysis of the materials seized on the premises of suspected persons. These materials include metals, moulding com]Dosition and miscellaneous chemicals. Since the chemist is consulted about so many aspects of the question, his opinion is also frequently asked about the use of various apparatus and appliances used in making counterfeit coins, such as crucibles, casting frames, moulds, flattening mills, punches, punching machines, dies and presses. Frequently such a23paratus is very primitive, but occasionally it is very complete and ingenious. Naturally no details or descriptions can be given. The expert to whom questions in connection with counter- feit coining are referred should familiarize himself with the methods used in the minting of genuine coins. Most cases of counterfeit coining are devoid of any sjoecial interest, apart from the ingenuity displayed in adapting ' La Nature, 1898, 128. G2 LEGAL CHEMISTRY primitive appliances and a])pliances intended for other j^ur- poses, to the needs of the coiner. In the important coining case already referred to, in which a large number of jDcrsons were condemned, considerable use was made of small portable punching machines such as are used for punching holes in iron plates. These machines were not only employed for preparing the blanks, but they were also fitted with dies and used as presses, although most unsuitable for this purjoose. The following particulars of a few special cases may be mentioned. 1. As possible connecting links between certain counter- feit coins and a suspected person, several pieces of white metal, and some similar-looking metal adhering to the end of an iron rod, which had manifestly been used as a stirrer, were examined. The defence set up was that these articles had no connection whatever with counterfeit coining but had been used for tinning copper saucepans, a common j^ractice in Egypt. Analysis however proved that the jjieces of metal and the metal on the rod were both identical in composition with the counterfeit coins, and differed con- siderably from the material ordinarily employed for tinning saucepans, and the man was convicted. |»3* 2. This was a case of English sovereigns which had been sweated, in some instances being reduced as much as half a gram each in weight. Examination jd roved that the faces of the coins had been protected, probably by grease or wax, and the edges then sweated by means of aqua regia, and traces of both nitrate and chloride were found on the coins. 3. Among a number of articles seized in one case were a small cylindrical piece of wood and a hammer. One end of the wood had the appearance of having been repeatedly struck, and on the other end there were impressions of parts of the design of a coin, and also some tiny particles of white metal, which on analysis proved to be largely silver, and wood fibres were found in a depression on the head of the hammer. Manifestly, therefore, both the wood and hammer had been employed together in some connection with silver coins, and it was confessed that they had been used to force COUNTERFEIT COINS 63 counterfeit coins out of the milling collar, A similar piece of wood, also bearing the impressions of parts of the design of a coin, and adhering to which were tiny particles of white metal too small to allow of analysis, were subsequently found in another case. Other instances in which impressions of coins have been found on various articles will be mentioned in connection with the subject of Stains and Marks, 4. In another case a minute fragment of metal, from which the test for copper was obtained, but which was too small for the re-actions for other metals to be observed, though judging from its colour the metal was not wholly coj)per, was found on a file seized in the house of a person suspected of making counterfeit coins, the coins in question being composed of copper and tin, BOOK OF REFERENCE. Manuel de Police Scieutifique, Vol. I, R. A. Reiss. Lausanne, 1911. DAMAGE TO CROPS The chemist is sometimes consulted with reference to damage to croj)s alleged to be due to such causes as smoke, dust, chemical fumes or tar. The following is a case in point. Certain market gardeners, who cultivated land along one of the main roads on the outskirts of Alexandria, brought an action against the Municijaality for damage to their crops, alleged to have been caused by the dust from the tarred road. On inspection it was found that in most instances there was no appreciable difference between the condition of that portion of the crop nearest the road and the portion farthest away. In a few cases, however, portions of the crop for about four metres on the side nearest the road were not so good as the rest, the poorness being manifested by the plants being fewer in number, smaller in size, and altogether not so strong and healthy as the rest. Considerable evidence of the ravages of insect pests was found and specimens were submitted to an entomologist, who stated that the damage Gt LEGAL CnE:MISTRY was caused by Thrips, Ai)hides and Aleyrodidae, but chiefly by Thri^is, and that some black patches on the plants, which the plaintiffs alleged to be tar, were caused by a black fungus growth on the sticky secretion of the Aphides. As tar however did exist in the dust on the plants, various experiments were made with growing plants and dust con- taining tar, and it was not found that any deleterious effect could be traced to the presence of the tar in the j)roportion used, which was considerably greater than the amount actually found on the plants in the case under consideration. Although there was damage to the plants in places, and although there was tar on the plants in very small amount, yet the damage was not caused by the tar, but by insect pests, and the crops specially attacked were those gro^^^ng in positions where the drainage was unsatisfactory, and where, in consequence, injurious salts had accumulated in the soil. These conditions alone, without the insect pests, would injuriously affect the crops. The jaortions of the crops that showed signs of damage were also those that were nearest to the road, and which would suffer most from the ordinary road dust, and which would certainly have been damaged if tar had not been used, the tar actually' being beneficial by reducing the amount of dust. From enquiries made the damage seemed to have become aggravated about a period that was coincident, not only with the beginning of the tarring, but also with a very considerable extension of traffic along that particular; road. In connection with this case, an agriculturist, who acted as an expert for the plaintiffs, sent a sample of the road dust to a chemist for analysis. The results of the analysis shoMcd the dust to consist of silica, oxides of iron and aluminium, lime, carbon dioxide, etc., as was only to be expected, seeing that the road was made with broken limestone. The expert, not understanding the manner in which the results of a chemical analysis are expressed, interpreted it wrongly, and thought that the lime shown in the analysis was present in the caustic state, and the alleged existence of caustic lime was made much of, it being stated very truly that caustic lime would cause considerable damage to plants. The lime however was of course combined in the form of DAMAGE TO CROPS 65 carbonate with the carbon dioxide also present and Was quite inert. At the time when tarring of roads was first introduced as a method of dealing with the excessive dust occasioned by motor traffic, many complaints were made that the particles of tar in the dust were injurious to vegetation. This, however, was never established, and undoubtedly by decreas- ing the amount of dust that otherwise would be deposited on the vegetation, tar is indirectly beneficial, and no direct injurious action of the small amount of tar which settles on the plants and trees bordering a tarred road has ever been proved. That vapours, such as those that are disengaged from hot tar during the time it is being used, might be harm- ful to plants in an enclosed space is not disputed, but this condition does not occur in practice and therefore need not be taken into consideration. Sometimes, however, there is a secondary and indirect result from the use of tar, an instance of which occurred in Cairo. Most of the streets were bordered with trees {Albizzia lebbek) which in many cases had almost reached their limit of age : many of these trees too had been subjected to attacks from the larvae of a particular beetle, which had left them riddled with holes. These trees had been accustomed to obtain considerable supplies of air and moisture by way of the surface of the ground, and when the road was tarred and the sidewalk asphalted and both thus rendered impermeable, the trees were suddenly deprived to a large extent of air and water, and hence their vitality, already low, was reduced still further, and it is not surprising therefore that some succumbed at once, and that many of the others soon became a prey to a scale insect which killed them. DOCUMENTS At first sight it might appear that the examination of documents was hardly within the province of the chemist, but when it is considered that a chemical and microscopical examination of the paper, a chemical analysis of the ink 6 66 LEGAL CHE:\IISTRY and a chemical examination of any discoloration or stains l^resent, are frequently necessarj^. it will be recognized that there is a large amount of purely chemical work in this con- nection. There are, of course, other aspects of the question which are in no way chemical, such as that of the identity or non-identity of different specimens of handwriting, but since the chemical side of the question is so ira2:)ortant, it is not unreasonable that the whole matter should be entrusted to a chemist who has specialized in such matters. In any case, however, the expert undertaking such work should possess some chemical knowledge, should have considerable experience in the use of the microscope, and should be an expert photographer. Since there are a number of books published which deal with questioned documents, ^ no attempt will be made to describe methods, but details of a few cases, together with notes embodying points of personal experience, will be given in order to illustrate various aspects of the subject. These cases may conveniently be classified as follows : — 1. Forgeries. 2. Anonymous Documents. 3. Illegible Writing. 4. Secret Writing. These various classes will now be considered. Forgeries. Forgeries include not only counterfeits of entire docu- ments, but also documents on which there are alterations, erasures, additions or false signatures. Forgeries may be written, typed or printed, or partly of one kind and partly of another, the most common forgeries being those of bank- notes, deeds relating to land and proix^rty. wills, certificates and receipts. When dealing with suspected forgeries all the expert's weapons are brought into play, and the paper, in- cluding the water-mark, if any, ink, writing (or printing) and any discoloration or. stains are all carefully examined. In one important land case in connection with which » The names of a few are given later. The best is that by Osborn. DOCUMENTS 67 one hundred and sixty-eight documents were examined, one hundred and sixty-three being forged, the methods of forgery adopted embraced practically all those known, some of the documents being entirely counterfeit, others being genuine documents tampered with in almost every possible manner, such as by the alteration of names and dates, the forging of signatures and seal impressions, the piecing together of parts of sej)arate documents to make an entirely new document, the addition of forged endorsements, the burning and staining of certain parts, the mounting on other paper to hide signs of erasure, and the removal of the whole or part of the original writing to make room for other writing. In the case of the title-deed of the land in dispute, which was a large document of between seventy and eighty lines and containing some seventeen hundred words, the whole of the original writing, except the signatures, had been removed and replaced by other writing, this being rendered possible by the document having been written with carbon ink on a thick, glazed, parchment-like paper. Several interesting points in connection with this document may be mentioned. In most deeds of this class which have been examined, it has been found that if the last line of writing would not normally end at the left-hand side of the paper or at the left-hand margin (Arabic writing is from right to left) the last words are stretched out, or the last letter is elongated, so as to reach the edge of the paper or the margin, and immediately below the last line of writing and immediately above the signa- tures of the witnesses (the signature to a deed of this kind is at the top, but the witnesses sign at the bottom) a line is begun at the right-hand edge of the paper or at the right- hand margin and stretches right across the paper, ending with the word " shehoud " (witnesses) that is to say the first letter of the word " shehoud " commences as a long stroke at the other edge or margin of the paper. In one such document examined the line stretched continuously across the paper from one margin to the other, the word " shehoud " being absent, while in another document the writing was continued down almost to the bottom of the paper and no line was present, the signatures of the witnesses being in the margin. In only one other case among those 68 LEGAL CHEMISTRY examined (probably more than a hundred altogether) was a line absent. In the case of the document in question only part of the characteristic line alluded to was present, the missing portion being that on the right-hand side where the line normally begins, and the writing of the document, where the line was missing, extended down to the signatures. Parts of the missing portion of the line however were still faintly visible in places, and it was evident that the line at one time had extended across the j^aper in the usual way. The last few lines of writing too were unduly crowded together, although plenty of room existed below the signatures, which could only mean that this space was not available and that the writer therefore was limited to the space above, and hence that the signatures already existed at the time the writing was made. The ink vrith which this document had been rewritten was of a brown colour and was jDossibly sepia, though this could not definitel}' be proved. Sepia however was found in the house of one of the accused persons. The original glazing of the paper had in large part dis- appeared and the paper had been scorched by fire in order to hide this and other susi^icious indications. The various points which require to be considered when dealing with forged documents will now briefly- be discussed. Paper. In many instances the nature of the fibre from which a document is made is immaterial, but in cases in which the document is an old one and its authenticity is questioned the composition of the paper may become of the utmost importance, since the date when most of the modern paper- making materials were introduced is known. The examination of paper is by means of the microscope. This can only be done after the paper has been broken up and suitably prepared, but the amount of paper required is so very small that it can be taken from a corner of the document without any detriment : it is not suggested how- ever that this should be done as a routine practice, but only in special cases. Before the paper is examined microscopically DOCUMENTS 69 the small portion dealt with is generally impregnated with a special staining solution which gives distinctive colours with the different fibres and so aids identification. One of the earliest substances used for writing upon was Egyptian papyrus, the fine layers of fibrous material from the stem of which were made into sheets, and it is from the name papyrus that the word paper is derived. After papyrus came parchment, which is still used for legal documents. Parchment is made from the skins of certain animals, chiefly sheep and goats. The finer qualities, made from the more delicate skins of calves and kids, are called vellum. Parch- ment was succeeded by rags, at first linen rags, and after- wards a mixture of linen and cotton, or cotton only. A letter dated a.d. 874, and documents which from internal evidence are believed to belong to the year a.d. 792, made of linen were found some years ago in the Fayum province in Egypt. I The date of the oldest manuscript in England on cotton paper is stated to be 1049.2 Although experi- ments in paper-making were made with a great variety of fibrous materials, rags were generally employed until the middle of the nineteenth century. Straw was first used in 1800, a book made from it being published in England at that date, I though it was not employed on a large scale until more than fifty years afterwards. The manufacture of paper from mechanical wood pulp dates from Keller's process in 1840,2 that of soda wood j)ulp from 1854,^ and that of sulphite wood pulp from Tilghmann's patent in 1866.^ One authority states that a patent was granted to some paper makers in Italy in 1826 for the use of wood pulp. 3 The general use of mechanical wood pulp, however, dates from 1870-80 and that of wood cellulose from 1880-90.4 Esj)arto was intro- duced into England about 1860. ^ Before 1799 all paper was hand-made, but in that year the first paper machine was invented in France, and in 1807 a paper machine was erected in England. ^ Blotting paper is mentioned as early as 1465 and fragments have been found in fifteenth-century ' The Manufacture of Paper, R. W. Sindall, London, 1908. 2 Paper Technology, R. W. Sindall, London, 1906. 3 Chambers' Ency., Vol. VII, 1908. 4 Deterioration of PajDer. Society of Arts, London, 1898. 70 LEGAL CHEMISTRY account books, and in the sixteenth century it is referred to as though it were well known ; • it was not in general use, however, until the beginning of the nineteenth century, a fine powder, such as sand, being employed instead, and even to-day sand is still sometimes used for this purpose in Egypt. Brown paper is referred to in 1570-1.1 Two cases in which the composition of jjaper has been of importance may be mentioned. In one instance a docu- ment dated 1213 a.h. (a.d. 1798) was composed entirely of chemically prepared wood cellulose although this material was not employed for paper-making until more than fifty years afterwards, and in another case it proved a useful point in favour of the accused that paper found in his house, which superficially resembled that of some anonymous corre- spondence, and was stated by one expert, who however had not examined it microscopically, to be the same, was of entirely different composition. In this connection it may be mentioned that a number of genuine old Arabic docu- ments, mostly title-deeds of land dating between 1136 a.h. (a.d. 1723) and 1287 a.h. (a.d. 1870), which have been exam- ined were all found to be composed entirely of linen. Sometimes a limit may be j^laced to the age of a document by means of a water-mark, the earliest known dating from 1301.2 In an important case, already referred to, in Avliich the title to a large area of land was in dispute certain receipts were produced dated 1294, 1295, 1296 and 1297 a.h. respec- tively (a.d. 1876, 1877, 1878 and 1879), all of which bore the Egyptian Government water-mark although this was not introduced until 1885. It may be mentioned that the ordinar}^ correspondence paper of the Egj^ptian Government had a date added to the water-mark for the first time in 1915, although certain stamped paper had borne a dated water-mark for many years previously, and certainly as early as 1887. In the case just referred to, two other receipts dated three months apart had originally formed part of the same sheet of paper and a portion of the same water-mark appeared on each, and it seemed improbable that part of ' Ency. Brit., mil. Vol. XX. Article "Paper." - The Manufacture of Paper, R. W. iSinclall, London, 1908. DOCUMENTS 71 a sheet of paper should be used on one occasion and the other part not until three months later. In another case a number of receipts, the dates of which extended over a period of one year and ten months, were examined and it was noticed that all were part* of similar sheets of foolscap, and after considerable trouble it was found possible to fit the various pieces together. It w^as seen that the order in which the pieces occurred did not correspond with the dates on the receipts, thus for example a receipt dated January of one year was part of the same sheet as a receipt dated January of the following year, while parts of other sheets, in no regular order, had been used for intermediate dates. This at once raised a presumption of forgery, since it seemed improbable that one part of a sheet of paper should be used one year and a second part not until twelve months afterwards, although meanwhile other sheets had been torn into similar pieces and used for a similar purpose. The water-mark on the paper was very helpful in the fitting of the various pieces together. A series of three crescent moons of different sizes is an old water-mark on paper used in Egypt and certainly occurs as early as 1188 a.h. (a.d, 1774) and it occurs in at least two different forms. In Brown's Travels to Darfur " papier des trois lunes " is mentioned as an article of commerce from Egypt to Darfur in 1793. A water-mark of three stars has been noticed on documents dated 1190 a.h. (a.d. 1776). In- connection with the important forgery case already mentioned the fact that blank sheets of paper bearing an unusual water- mark, which occurred on some of the forged documents, were found in the houses of two of the accused persons was a small link in the chain of circumstantial evidence which convicted them. Occasionally documents are discoloured intentionally in order to give them a fictitious appearance of age, or they are scorched and partly burned and sometimes creased and torn for a similar reason. These same devices are also resorted to for the purpose of hiding evidence of fraud. Discoloration due to age is largely a process of oxidation brought about by natural means and it takes place in pro- portion to the extent to which the paper has been exposed 72 LEGAL CHEMISTRY to the air and light, and hence the outsides and edges of old documents, which are the most exposed, become the most discoloured, the discoloration progressively diminishing to- wards the less exposed parts. In addition to the general discoloration however there are frequently on old documents brown spots due to mould which are very characteristic both in appearance and distribution. It may be mentioned that these spots become more or less translucent when wetted Avith water, regaining their original appearance when dry, the smaller spots as a rule becoming entirely translucent while the larger ones remain opaque at the centre. This is a very simple test and one that may be applied to almost any document without fear of injury. Sometimes isolated brown spots not caused by mould but by iron or other impurities also occur. Other natural causes for the discoloration of documents are exposure to dust and dirt and occasionally staining by fruit juice, grease and the excreta of rats, mice and insects. In the latter case the outsides and edges of the documents generally suffer the most. Where a document has been intentionally discoloured with dust, dirt or mud, this is evident as a rule by the discoloration showing definite streaks or lines when carefully examined, the dirt generally having been rubbed on either with a cloth or \vith the hand. Discoloration may also be due to heat, in which case it is an actual partial burning of the surface of the paper, which becomes very brittle if the burning is severe, and when one side becomes scorched, unless the paper is thick, the opposite side also shows signs of burning. When a number of docu- ments are ex])osed to fire while together those on the outside naturally suffer most, and those on the inside may be only slightly burned or not burned at all, and any holes produced correspond in relative position in the various documents. The edges of the documents too, being loose, always burn first. These facts are frequently forgotten by forgers whose handiwork shows a definite selective action which is unnatural, certain documents or parts of documents being burned or spared in a manner that could not jjossibly be accidental. In one case a piece of blank paper which had been scorched in the same suspicious manner as some forged DOCUMENTS 73 documents was found in the house of one of the accused persons. Artificial discoloration made to simulate age is produced by means of a coloured solution. The author has never been able definitely to establish the nature of any solution employed, but in the East coffee is very probable while in the West tea might be used. A water extract of tobacco or a dilute solution of potassium permanganate would also serve the same ]3nrpose. The use of a coloured solution is generally indicated by the characteristic shape of the edges of the discoloured areas, or the way in which the liquid has run may be plainly visible, and a thin dark line sometimes occurs where there were any very marked creases on the paper at the time it was treated. Occasionally too portions of the paper, often very small, may be found which have altogether escaped the action of the solution. In cases Avhere documents have been creased or torn to give them a fictitious appearance of age and constant use they are sometimes mounted on another sheet of paper. This may also be done to hide signs of erasure or to prevent too minute an examination. Sometimes a document mounted on other paper is in several pieces, and when this is the case the edges at the joins should always be carefully examined. In several such cases it has been found that the edges of the different pieces did not correspond, the separate pieces being parts of different documents put together to make an entirely new and fictitious document, or the bottom piece bearing the signature has been part of a genuine document to which writing specially prepared for the purpose had been joined. In other cases the two pieces of paper at a join have over- lapped, and although a line of writing was partly on one piece and partly on another, it did not extend to the edges of both, but only to the edge of the piece which was upper- most, leaving a margin without writing on the under piece, which was conclusive proof that the writing had been done after the pieces had been joined together : it has also been found that small portions of some of the letters of the writing at a join existed on the paper used for mounting, which again was proof that the mounting paper was in place when the document was written. 74 LECAT. CIIKMISTRY It is (piite a coddhoh occurrence in Egypt for old tillo- dceds of land to be written on more than one sheet of paper, the separate sheets being joined end to end ; thus one such document (examined was written on nineteen separate pieces of paper and measured altogether about seven and a half metres in length : sometimes such deeds are twenty or even thirty metres long. In the particular case above-mentioned the safeguard against the possible fraud of tampering with one or more of the pieces consisted in the fact that the writing had been so arranged that a line was across each join of the paper. Ink. The nature of the ink should as a rule be determined, since this may serve as an indication of age or as a proof of alterations or additions. The principal kinds of ink employed are carbon ink, iron- tannate ink, logwood ink and aniline ink, all of which may be differentiated by chemical tests, even when in the form of writing. The testing is carried out by applying minute drops of various re-agents to the writing and examining the result with a lens, and this can be done so carefully that any marks left are so small that it is difficult afterwards to find the spot tested. In view of the comparatively large number of re-agents for testing ink on documents recommended in various books, perhaps it will be as well to state that very few are actually required, the most useful being dilute hydrochloric acid (strength not more than five per cent.), dilute caustic soda {strength about two per cent.) and a solution of bleaching powder, or better, of sodium hypochlorite. Oxalic acid, tartaric acid and acetic acid are occasionally useful sub- stitutes for hydrochloric acid and may be employed in greater strength than the mineral acid without fear of injuring the paper. Sulphuric acid, although frequently recommended, should never be used, since it will inevitably seriously damage the document. This damage may not take place at once, but only gradually, and hence may not be apjjarent until some time afterwards. Potassium ferrocyanide, which is frequently employed as a test for iron in ink, is less valuable DOCUMENTS 75 than caustic soda, since it labours under several disadvan- tages, one being that it readily deconij^oses, giving the very re-action (a blue colour) it is used to test for, and another that it re-acts with any iron compounds in the paper as well as with those in the ink. Also, since ferrocyanide solution is acidified with hydrochloric acid before use, this latter renders visible the blue colour due to any provisional colour- ing matter in the ink, which masks any other blue due to iron compounds. Caustic soda has also a disadvantage in the way it spreads on the paper, but the effect of this may be minimized by using the smallest possible quantity and by removing the excess with blotting paper as soon as the result of the test has been noted. No matter what re-agent is used, it is a wise precaution to remove the excess remaining after the re-action has terminated, by means of blotting paper, or better to wash it off by applying successive drops of water which are afterwards absorbed by blotting paper. As mentioned elsewhere, an excellent test for carbon ink may frequently be made with plain water and blotting paper. In one book dealing with questioned documents, the chemical testing of ink is described as " quite simple," and it is further stated that " the cost of the necessary material and the time required to make oneself proficient as a capable tester are so slight that even the small fee that would be charged by a chemist is scarcely worth paying." It is cer- tainly true that the cost of the re-agents required is slight, chiefly because the quantity used is so minute, and the method of testing like everything else is simple when one knows how to do it, but the way proposed of determining the presence of acid in an ink on a document by placing " the tip of the tongue to a thick stroke " cannot be recommended, nor is it advisable to put so much water on a document that some of it can subsequently be poured into a test tube, as is advocated in the book in question. A " point of a pin " as suggested as a means of applying acid is also unsatisfactory. The only right way of testing ink on a document is that already mentioned, namely to apply an exceedingly small drop of the requisite re-agent by means of a very fine capillary glass tube, and to examine the result with a 76 LEGAL CHEMISTRY lens. When writing lias been chemically tested a note should always be taken of the exact spots to which the re-agents have been applied and these should be indicated in the reiDort. It cannot be insisted upon too strongly that questioned documents are j^recious things, and should be treated accord- ingly, and no one who has not had considerable experience in delicate manipulation, should be allowed to test them. Sometimes an alteration to a document consists of a few letters or figures only, or even part of a single letter or figure, and unless the greatest precautions are taken, the disputed portion of tlie writing will be so defaced that it becomes quite useless as evidence. In cases of this nature it is inadvisable to test the ink at all. In this connection it may be mentioned that many of the results of the chemical examination of ink on documents, which are to be found in the literature of the subject, have reference to an iron-tannate ink without any provisional blue colouring matter, and therefore are very misleading, since practically all ordinary writing inks now contain a blue colour. When dealing with blue aniline ink the following caution should be noted. An ordinary iron-tannate ink containing a blue colouring matter if very recent is blue and when tested Avith hydrochloric acid, oxalic acid, tartaric acid or acetic acid it remains blue or may become still more blue, owing to the bleaching of any colour due to the iron-tannate, and the consequent rendering visible of all the blue already present. Such an ink too gives a reddish-brown colour when tested with caustic soda. When blue aniline inks, which are some- times used for writing, are tested Avith these same re-agents, they also remain blue with the acids, and in some cases give a reddish-purple colour with the caustic soda, and therefore, unless care is taken, such an ink might be mistaken for a very recent blue-black iron ink. Some, though not all, of the blue colours that might be employed as ink may be distinguished from one another by chemical tests, even when in the form of writing, but no re-actions can be found that will differentiate some of the violet colours that might possibly be used. Generally DOCUMENTS 77 however only one violet, namely methyl violet, is employed. For red inks there are satisfactory tests. The dye prin- cipally used for making red ink is eosine, but cotton scarlet, ponceau scarlet or fuchsine might also be employed, and the following method of distinguishing between them when on a document may be mentioned. With bromine water eosine becomes yellow, but the red colour returns on the addition of caustic soda ; cotton scarlet also becomes yellow with bromine water, but on the addition of caustic soda to the yellow spot a brown colour is formed ; caustic soda applied directly to the cotton scarlet produces a puce colour which disappears after a time ; with bromine water ponceau scarlet at first becomes yellow and then bleaches ; bromine water turns fuchsine a violet colour, which becomes yellow or orange on the addition of caustic soda. In connection with the determination of the age of writing it may be stated that neither carbon jnk nor aniline ink can be dated even ajjproximately from chemical evidence, since neither undergoes that progressive chemical change with lapse of time that is so characteristic of an iron-tannate ink. With res]3ect to the change that takes place in iron-tannate ink the following observations and experiments may be quoted. The writing in a number of registers extending over a period of fourteen years was examined. It was found that some of the writing fourteen and a half years old (the oldest of the registers dated fourteen and a half years from the time the examination was made) when seen with the naked eye was grey, some black and a small amount brown. Of the writing in the subsequent years part was grey and part black, but none brown ; the writing from six months to eighteen months old was chiefly black. In no instance was there any blue tint. No writing less than six months old was examined. The ink used' was a blue-black iron-tannate ink, but possibly not of the same make in every case A number of dated documents were also examined. These varied in age from one month to seven years. To the naked eye none of the ink showed any blue tint, but with one exception all were grey or black, the exception being brownish- 78 LEGAL CHEMISTRY black and the document four and a half years old. Under the microscojDe most of the documents, up to and including those three years old, showed a definite blue tint, the blue being more marked the more recent the writing. There were however two exceptions, one being four months old and the other two and a half years old, and in both instances the colour of the ink varied from grey to black. Beyond three years no blue tint was distinguishable, the ink being brown in one case (four and a half years old) and grey or black in all other instances. In the above-mentioned cases therefore no blue was visible to the naked eye after one month (no observations of ink less than one month old were made), but blue was visible with the microscope up to three years, with only two exceptions, one being four months and the other two and a half years old respectively. In some tests made it was found that in the month of January in Cairo, Stephens' blue-black writing ink lost its blue colour to the naked eye in two days, one locally-made blue-black writing ink lost its blue colour in one day, AAhile in the case of a second locally-made blue-black ink for fountain pens, after the blue colour disappeared a violet tint formed which persisted up to and including the twelfth day from the time the writing was made. With the micro- scope all three inks showed a violet colour four months after the writing was made. Mitchell I states that an iron-tannate ink becomes almost completely oxidized in about six days. Osborn - states that for a blue-black iron-tannate ink to appear black to the naked eye a period of from one to two weeks is required in the summer, and from six to eighteen weeks in the winter, while for the ink to be of a real neutral black, even when examined microscopically, a period of from fourteen to twenty-four montlis is required, and that the colour is then fixed for a ])eriod of from six to ten years, after which it begins to turn yellow at the edges, finally becoming a yellowish brown. No general rule however exists for determining the age ' Anali/nl, inOS. SO - Questioned Documents. DOCUMExXTS 79 of an ink from the colour, since much dejiends upon the nature of the ink and whether or not it was fresli \\hen the writing was made, or whether it had already been exjjosed for some time in the ink pot, also upon the degree of exposure to which the writing has been subjected, the temperature and humidity to which it has been exposed and the nature of the paper, and whether or not the writing has been blotted. The ancient Egyptians used a carbon ink, as also did the Greeks and Romans, the latter of whom too made an ink from sej^ia.^ The earliest reference to an iron-tannate ink is in the eleventh centur3^I Colouring matters, such as indigo, were used to a slight extent to strengthen the colour of the ink during the eighteenth century, but it was not until the nineteenth century that the modern blue-black ink containing a provisional colouring matter was employed. ^ The use of a decoction of logwood as an ingredient in ink was known as early as 1763, and at first the logwood was employed as an addition to iron-tannate ink, but in 1856 dogwood was used with j)otassium chromate and in 1859 with alum, in both cases without any iron compound.^ The first aniline dye was mauve discovered by Perkin in 1856 3; in 1859 fuchsine was isolated and aniline blue in 1861 2 ; in 1863 Hofmann discovered the violet that bears his name - ; Bismark brown was made in 1866,3 eosin in 1874,4 and malachite green in 1878.5 The first British j)atent for the use of aniline dyes in ink was dated 1861, followed by others in 1862.i Nigrosine was introduced for stylograjihic pens in 1869. ^ Coloured inks however were known before the introduction of aniline dyes, thus green ink, probably a mineral product, was used both by the ancient Egyptians ^ and also by the Romans. ^ Carbon ink is still largely emjDloyed for writing purposes in Egypt at the present day ; one variety obtainable in the ^ Inks, Mitchell and Hepwortli, London, 1916. 2 W. H. Perkin, J. Soc. Arts, 18(i8. 3 Melclola, J. Soc. Arts, 1886. 4 The Chemistry of the Coal Tar Coloiu-s, Benedekt & Kncclit, 1889. 5 W. H. Perkin, J. Soc. Chem. Ind., 1885. ^ A Guide to the Egyptian Collection in the British Museum, London, 1909. 80 LEGAL CHEMISTRY bazaars is called Tahrizi ink, and is stated to come from Persia. The best quality of carbon ink consists essentially of carbon obtained as a deposit during the partial combustion of organic materials such as oil and resin. A recipe for making ink of this kind from incense, the ink being used for writing religious books, has been kindly supplied by a priest of the Coptic Church. The recipe is as follows : — Put a quantity of incense on the ground and round it place three stones or bricks, and resting on these, an earthenware dish bottom upwards covered with a damp cloth ; ignite the incense. The carbon formed will be deposited inside the dish, from which it is removed and made into ink by mixing with gum Arabic and water. An old Arabic book in the Sultania Library, Cairo (unfortunately anonymous and undated), contains a recipe for making what is called Persian ink. The method is to take date stones, put them in an earthenware vessel stoppered with clay and put the vessel over a fire until the next day, then remove, allow to cool, grind and sift the contents and make into ink with gum Arabic and water. Such an ink is of a very different composition from that previously referred to and may contain little or no free carbon. When wood or similar organic matter is charred by heat it is generally assumed that the resultant blackening is due to the formation of free carbon, and under certain conditions of temperature this is undoubtedly the case, but various black organic compounds, such as tarry matter, are also formed, and it seems possible that at relatively low tempera- tures free carbon may be almost or entirely absent. As the .result of experiments made on the solubility of charred wood in a solution of bleaching powder and in nitric acid. Boodle ^ comes to a similar conclusion. ^^ Having occasion to consult, in the Government archives, Cairo, some old Arabic documents dating between 1026 a.h. (a.d. 1617) and 1288 a.h. (a.d. 1871) it was noticed that although generally speaking the ink was black, yet in some cases it was brown or partly brown. It was not possible to examine the ink chemically in these particular instances, > Tlio Nature of Charred Wood. L. A. Boodle. Bull of Misc. Inf. Boyal Botanic Gardons, K^w, London, 1917. DOCUMENTS 81 but in the case of other documents which have been examined, in one instance a series of eight title-deeds for land varying in date from 1255 a.h. (a.d. 1839) to 1287 a.h. (a.d. 1870) the same phenomenon occurred, and the ink was undoubtedly nominally a carbon ink, and the fact of such ink becoming brown with age must be accepted. This at first sight seems extraordinary and even impossible, since one of the char- acteristics of carbon is its durability, carbon ink being always regarded as the type of a permanent ink. It is of course not contended that ink in which such change has taken place was ever a good quality carbon ink, for this is manifestly not the case, but it is stated that the ink in question is not an iron ink, but has been originally a black or practically black ink, which was accepted and used as an ink of the carbon type, and to-day carbon ink is still generally employed for documents of the class of those in question. An ink made according to the second of the methods mentioned might well be of this sort. In any case it must be assumed that when the document was finished, the writing was uniformly of a dark and practically black colour, and hence the dis- appearance of this colour must be accounted for, and it is suggested that the ink contained little or no free carbon in the first instance, and that a definite colour change has taken place, any small amount of carbon present being masked by the brown colour formed. In this connection a number of old manuscripts in the Sultania Library, Cairo, were examined, and it was found that here too in many cases the ink was brown. Thus the ink on manuscripts written on papyrus dated between a.d. 622 and 719 though often black is sometimes brown, and in some of the old manuscript Korans dating between a.d. 719 and 912 the ink is also brown and sometimes faded. In several instances where the writing is black there is a brown-coloured zone round the letters, and where writing shows through the paper from one side to the other it is often brown. It has also been noticed that where writing has become accidentally copied on to an opposite page the copy may be brown although the original writing is black. In the case of two manuscripts on leather dated a.d. 848 and 853 respectively the ink evidently has originally been black, and is still black in places, but in other places 7 82 LEGAL CHEMISTRY it is white and inaiiifetitly some change lias taken place, but of what nature it is impossible to say without a chemical examination, the white however does not appear to be a fungus growth on the surface of the ink which at first was thought possible. When carbon ink is used on a good quality well-sized paper, such as the parchment-like paper frequently employed in Egypt for title-deeds of land, the ink may sometimes readily be removed. A common illustration of this is that when testing carbon ink it is frequently noticed, after apply- ing the usual tiny drop of re-agent and using blotting paper to absorb the excess, that the ink on the small portion of the writing tested has partly or wholly disappeared from the paper, and if the test solution employed happens to be one that bleaches, the explanation at once suggests itself that the colour has been bleached and therefore is not carbon, though what has actually happened is that the ink has become loosened from the paper by the solution and has been removed mechanically by the blotting paper, to w^hich it can be found adhering. Care therefore is necessary to dis- tinguish this w^ashing off from bleaching. The fact that carbon ink can readily be removed from modern Egj'ptian documents provides a good test for this ink. A drop of water is placed on a small piece of blotting paper which is then applied to the writing and pressed down with the thumb nail. If the ink is a carbon ink a little will generally come off and will be found as a black stain on the blotting paper. That carbon ink could be removed from documents was known to Pliny, who states that it could be done with a w^et sponge. I In several cases investigated alterations to documents written with carbon ink have been made with an iron-tannate ink containing a provisional blue colouring matter, and in one instance a document written with carbon ink had been altered twice, in one place with an iron-tannate ink and in a second place with logwood ink. In one case a document written with iron-tannate ink had been altered with carbon ink. ' Inks, Mitchell and Hepivorth, London, 1916. DOCUMENTS 83 Coloured aniline inks, chiefly violet, are used largely in the East, even for important documents such as wills, pro- missory notes, deeds of sale and receipts. Ink of this kind fades on exposure and the nature and extent of the exposure condition the appearance of the ink much more than mere age. Aniline colours in the form of ink of the kind used for duplicating purposes with such an apj^aratus as the hectograph for example, are frequently very resistant even to strong sunlight, apparently on account of the thickening ingredients present, whereas copies of documents made with such ink fade readily. r^ Sometimes a signature written with violet ink is suspected because it is lighter coloured than the ink on the body of the document or than that of other signatures, but little can be done in such cases and the lighter colour may simply be due to the ink having been blotted. In one case the authenticity of a document written in violet ink was ques- tioned because the ink was darker in colour than that on another document bearing the same date ; the evidence however was in favour of it being genuine. ^^ In a case in which the validity of a document relating to the sale of land was contested, the whole of the document, including the signatures, was written with violet ink and therefore no chemical examination of this could give any indication of its age. The prosecution contended that the signature of the most important witness had been added at a later date than the other signatures, while the defence produced photographs (both negative and prints) showing this signature and the absence of a certain dated registration stamp which seemed to prove that the signature had been on the document at a date prior to that assigned to it by the prosecution. The fact that the grain of the paper of the document and considerable gradations of light and shade existed on the photographs, as also two numbers which showed through the paper from the opposite side, was definite proof that the registration stamp had not been blocked out or otherwise removed, and that the j)hotograph had actually been taken before the document was registered. The regis- tration stamp too crossed a fold where a corner of the paper had been turned down to allow an endorsement on the other 84 LEGAL CHEMISTRY side to show on tlie photograph and the sequence of the fold and some writing on the registration stamp corroborated the other evidence that the photograph was taken before the document had been registered. When dealing with photographs it should not be forgotten that both negatives and prints are very easily " faked." Thus a negative may not be the original negative, but a secondary one on which something not on the original has been added or from which something has been omitted, and in the same way the j^rint may have been made from a " faked " original or from a secondary negative. It is a commonjjlace of photography to block out undesirable features in a negative and to make additions, such as a suit- able background to a portrait or clouds in a landscape. In another case examined a document bore various genuine consular registration stamps and was endorsed on the back with violet ink which partly showed through the paper. As seen from the face however the colour of the endorsement was not violet but green, and since it is a well- known chemical fact that certain acids turn aniline violet a green colour, acid was tested for and was found to be present to an extent imjjossible in a paper that had not been specially subjected to acid treatment, and on further examin- ation it was discovered that part of the original writing had been effaced ana a forged name and other details substituted. The fact that gum had been used in this and in several other instances to reglaze the paper after the original writing had been removed was additional proof that the documents had been tampered with, since gum is never used for such a purpose by the paper manufacturer. Occasionally documents are submitted to the expert in which it is stated that alterations have been made, but which on examination are found to be perfectly genuine. Alterations may be alleged because the ink has " run '" in places, and fraudulent additions may be suspected because some of the writing is unnecessarily close together. It may however be possible to prove not only that no alteration or erasure has been made, but that any " running ' of the ink is due entirely to the ])oor quality of the sizing of the paper, and if any part of the writing touches or crosses another DOCUMENTS 85 part, the determination of the sequence of the strokes wi;l settle the question of whether additions have been made or not. In case of an erasure where traces of original writing, which it is desired to decipher, still remain, it will be found that a photograph taken by transmitted light will sometimes show greater detail than one taken by reflected light, and a very simple and satisfactory method of taking the trans- mitted light photograph is by contact, emjiloying a plate such as is used for lantern slides. If the document is a small one, or one that can be folded without injury, the exposure is best made in an ordinary printing frame, the document taking the place of the usual negative and the photographic plate that of the printing paper. If the document is one that cannot be put in a frame, such for example as a register, the photographic plate is placed, with the sensitized face upwards, immediately beneath the writing it is desired to photograph, which is covered with a plate of clear glass to keep it flat. The exposure is made in artificial light and frequently several trials are necessary before the correct time of exposure is found. The negative gives a laterally reversed print if this is made by contact in the usual way, but by projection a correct print may be obtained. For purposes of examination however the negative is generally more satis- factory than the print and if viewed from the film side, it shows the writing uninverted. Prints however are necessary for attaching to the report or for presentation in Court. A few special cases which have been investigated and which contain points of interest will now be quoted. In one case a register was submitted for its age to be determined, it being suspected that an original register had been made away with and another specially written one substituted. The book was new-looking and only slightly soiled and had the appearance of having been very little used. The paper label on the back was also remarkably clean, and was partly detached. In the case of other similar registers the labels had come off entirely at some time and had been fastened on again with extra gum, abundant traces of the operation being left. Nothing of the sort however had happened with the register in question. At the end of the register a sheet 86 LEGAL CHEMISTRY of foolscajD pai:)er had been inserted for use as an index. Other registers had been treated in a similar manner, but in this case the foolscap bore a water-mark which showed it to be of a later date and therefore of a later issue than would probably have been the case had the register been the original one. A chemical examination of the ink proved it to be an ordinary iron ink, and provided abundant evidence that it was all approximately of the same age, and that part of it at any rate was not as old as certain of the entries purported to be, some of which were dated more than twelve months previously : all the ink was fresh-looking and had probably been blotted, and in no case was it black, even to the naked eye, and it was all very blue when seen under the microscope. In another instance a register which was presented in Court in support of a case was found on examination to have been specially j^repared. The dates of the entries extended over rather more than a year, and it was stated that the register had been kept and entered up in the office of a flour mill. The book however was clean and new-looking and quite free from flour and dust, the ink was a bluish-green aniline ink, and so could not be dated from chemical evidence, but it was exactly the same colour throughout, and the writing was in the same hand and was all done with the same or a similar pen, but showed signs of haste or fatigue towards the end. In two instances an entry which belonged to several lines below had been made and afterwards erased, and the dots under a word to indicate repetition, which occurred plentifully on every page, had in some cases been written vertically on a number of different lines at the same time, the ink showing progressively diminishing intensity of colour from the top to the bottom of a page. In several instances letters enclosed in envelopes, which have been submitted in support of cases, have been found on examination to be fraudulent, a genuine envelope with a post mark of the required date having been obtained, and a letter forged to accompany it. Forgeries of this kind may generally be exposed by a difference in the nature or age of the ink or by a difference in handwriting. In one case the envelope bore the printed name and address of a certain DOCUMENTS 87 hotel, while the paper bore no such indication ; in another instance a grease stain, going through the envelope from front to back, did not occur on the letter ; in other instances the envelopes had been mutilated. The testing of documents for erasure by means of iodine vapour or heating, both of which are sometimes recommended, is not as a rule either advisable or necessary. Pens. A reed pen is still largely used in Egypt for Arabic writing, although it is being gradually superseded by a special form of steel p'en. The difference between writing made with a reed pen and that made with a steel pen is generally very marked. Handwriting. In the examination of written forgeries a study of the handwriting is of great importance. It seems at first sight to be a very simple matter to determine whether one speci- men of writing is in the same hand as another or not, and it is quite a common experience for the ordinary man to be appealed to on such a question, and most people are quite ready to give a decision. • Even the few who disparage hand- writing experts because of the mistakes that have sometimes been made, unconsciously employ the method of comparison of handwriting in their own private affairs, and notice, and even act upon, resemblances and differences found. The untrained person, however, bases his comparison upon the broad features of the writing only and does not as a rule pay any attention to details. vSince, however, the aim of the forger is to deceive, a clever forgery, in order to pass muster at all, must necessarily resemble in its general asjDect the writing forged, and therefore something more than a superficial likeness or difference is required before any useful opinion can be pronounced regarding the genuineness or otherwise of a specimen of writing. The study of hand- writing to be of any value must be conducted according to strictly scientific methods, which can only be done by those possessing special experience, and hence in all cases of doubt 88 LEGAL CHEMISTRY or dispute regarding the authenticity of documents the matter should be referred to an expert, for not onl}^ niay he discover characteristics in the handwriting that make its origin certain, but not infrequently small points in con- nection with the paper or ink, which would be passed un- noticed by an untrained observer, will be found and may prove of considerable value as evidence. A mere opinion however that different documents are or are not in the same handwriting is of very little value unless the expert is able to demonstrate this in his report or in Court, and when the similarities or differences are substantial this can usually be done by means of enlarged photographs. • The exjDcrt should be particularly careful to avoid being misled by a general resemblance of style due to nationality or other cause and should never forget that members of the same family frequently write alike. It has been noticed that EgyjDtian clerks writing English often have a general similarity of style. The examination of signatures resolves itself largely into a comparison of the suspected signature Avith as manj' others known to be genuine as possible, but includes also as a rule an examination of the nature and age of the ink. Some- times however it may be inadvisable to test the ink, parti- cularly in the case of an Arabic signature, which may consist of a few strokes only, since in some cases it can be foreseen witiiout testing that any evidence obtained would not be decisive, whereas it may be most important that there should not be even the slightest mark made on the writing since this might be construed into an attempt to tamper with the signature. Arabic names as written are frequently very short and offer a very small field for comparison, and superficial differ- ences between two Arabic signatures are sometimes due to one having been written with an Arabic reed pen and the other with an Arabic steel pen or with a European pen, or arise from the fact that one has been written with the paper placed flat on the table or other hard surface in the Western manner, while the other has been written Avith the paper held in the hand or resting on the knee in the Eastern way. Sometimes, too, some of the letters arc written over a second DOCUMENTS 89 time or are touched up without any fraudulent intention. The greatest caution is necessary before giving a definite opinion regarding the genuineness or otherwise of a signature, and more particularly of an Arabic signature. Banknotes. The notes of all banks are occasionally forged, and those of the National Bank of Egypt are no ejcception. Most of the forgeries are poor, both the engraving and the colouring being very crude, and it is a wonder they deceive any one, but some few have been very well executed. One case submitted as forgery was merely a clever confidence trick in which a rough negative cojDy of a Jbanknote played a part. Finished notes were not made, nor was there any attempt to make them, the victim, however, being persuaded that forgeries, which would be quite undetectable, could be executed in a simple and inexpensive manner if he would supply the necessary notes for reproduction, the intention of those who worked the scheme being to secure the genuine notes and then to disappear. Some of the forged notes were entirely hand-drawn, and from internal evidence it was manifest that they were the work of at least two different persons. ' In most instances the outlines of the main features had been traced from a genuine note and the design then worked over by hand and the details filled in. At a distance the general ajjpearance of the face of these notes was fairly good, since the colour approximated closely to that of the original, but the colouring on the back was crude. Some of these notes were only of a value of fifty piastres each (approximately ten shillings) but others were for five pounds. The evidence indicated that the forger of most of the notes was unacquainted with English, but was familiar with Arabic and was able to write it well, though not perfectly, and therefore either that he was not an Egyptian or that he was not well educated. This man was finally arrested and proved to be an uneducated Egyptian whose usual occupation was that of tinsmith. Others of the same notes were probably the work of an Englishman or British Colonial, the English being correct and the Arabic nonsense, and were signed D. Spoof. Forgeries 90 LEGAL CHEMISTRY of banknotes executed by hand however are not unknown elsewhere, and in 1913 pen and ink copies of Scotch notes for £1 and £5 respectively were made in a convict prison, and during the war of 1914-18 two similar cases were rej)orted in the daily press, one being the forgery of English ten shilling Treasury notes and the other the forgery of ten shilling and one pound Treasury notes, the forgeries being clever pieces of penmanship in both instances. On one occasion a few sj^ecimen notes of a new issue of Egyptian notes were found in circulation, the word " speci- men " having been erased and a forged signature added in indelible pencil. Postage Stamps. A study of the methods used by stamp experts for exam- ining postage stamps will well repay any one having to report on questioned documents. The philatelist takes account of the nature and colour of the paper, the water-mark, the kind and size of the perforations, the colour of the stamp, the kind and size of the type used for the lettering, including that of overprints and surcharges, and the nature of the printing process employed and, above all, he looks for minute differences in the design, all of which necessitates keen obser- vation and a careful comparison with other stamps. In this connection the re-use of postage stamps from which the cancellation marks have been removed may be considered. The usual method of cancelling postage stamps is by means of a metal stamp and carbon-oil ink, and if the stamp is well impressed with a good blow, the oil penetrates the paper carrying some of the carbon with it, and althougli the oil may be dissolved out by suitable solvents, the carbon remains and cannot be removed by any chemical means, but only by erasure, which is easily detected. The colour of the ink too with which postage stamps are printed is frequently intentionally somewhat fugitive, and this is acted upon and partly dissolved by any solvents employed to remove the cancellation mark. In several cases investigated the removal of the marks had been clumsily done by erasure, and with a lens l)oth the signs of the erasure and the remains of the cancellation marks could be plainly seen. DOCUMENTS 91 Anonymous Documents. In the case of anonymous letters not only should the writing be examined and compared with that of the suspected person, but the paper and ink should also be carefully exam- ined, since these may provide important clues. In many instances the writer of anonymous letters is never traced, but in a few cases very definite proof of identity may be obtained, and even when this cannot be done it is sometimes possible to clear a jDcrson who has been wrongly suspected. In a country like Egypt evidence of nationality, which can sometimes be proved from the writing, may be very useful. In one instance investigated, in which it was important to trace the origin of an anonymous document, this was done from the evidence afforded by the ink, that on the document and some found in a bottle in the house of the suspected person, when examined and compared, being found to be characteristic and identical ; it was a blue-black writing ink of poor quality and contained a large amount of finely divided insoluble matter, and had probably been made from ink powder. In another case, well-marked finger prints were found, and the document was therefore referred to the finger print department. In theory, the examination of Arabic writing should not present any greater difficulty than the examination of any other form of writing, since whatever language a man uses, he unconsciously imparts to the writing certain char- acteristics which are personal and peculiar, and by means of which his individuality is expressed and may be recognized. In practice, however, the author has found Arabic writing much more difficult to examine than either English or French, probably because of his imperfect acquaintance with Arabic. Illegible Writing. This refers to writing (or printing) which has faded or which has been partly effaced, and not to that illegible on account of the manner in which it is written. The possi- 92 LECxAL CHEMISTRY bility of restoring faded writing depends upon the composition of the ink and the conditions which produced the fading. Inks containing iron offer the best prospects of restoration, while aniline inks as a rule cannot be restored. Iron ink may be restored by brushing over with a dilute solution of tannic acid or ammonium sulphide ; the use of an infusion of galls for a similar purpose was described as earlj^ as 1660. Pencil marks which have been partly effaced may some- times be deciphered if they are photographed by side illumin- ation, or they may be developed at the back of the paper by brushing it over with a coloured solution or a coloured powder. Sometimes it becomes necessary to decipher writing or printing which has been deliberately obliterated. As a rule this can easily be done, and indelible pencil, blue pencil, blue ink, blue-black ink and printer's ink can all be removed sufficiently by treatment with suitable solvents to enable the matter underneath to be read. On one occasion in connection with a crime, a letter was found so soaked in blood as to be quite illegible, and it was desired to remove the blood so that the writing could be read. This however proved impossible since the ink used was aniline blue soluble in water and in all the other solvents in which the blood was soluble. When deciphering writing which has been partly effaced the task is much more difficult when the language is a foreign one, since with a language which is familiar a certain amount of reasoned guess-work can be indulged in by means of which a working hypothesis is obtained, which can be verified or discarded later. Secret Writing. The most important kind of secret writing is that by means of ciphers and codes, and after this in ini])ortance comes the use of invisible or sympathetic ink.' The former ' During the war of 1914-18 a iiroclaination by the CJeneral Officer CommandiTig in Chief His Britannic Majesty's Forces in Egypt pro- hibited the \ise of secret writing in the following terms : " Xo person shall make use of invisible ink or of any other medium for writing which is not \isiblc unless subjected to heat or to some other treatment." DOCUMENTS 93 will not be dealt with at all as it is entirely outside the author's experience, and also it is not a chemical question. The latter will be treated very briefly since there are many things in connection wdth the subject which it is inadvisable to publish. Any colourless or almost colourless solution that can be used with pen and paper may be employed as an invisible ink, even plain water. Descri^^tions of a few invisible inks may be found in various books, as also the methods of developing them, but the possibilities are almost endless, and a large number of such inks could be devised by any chemist for which it would be practically impossible, without being informed of the nature of the ink, to find the correct developer. This does not mean however that development would be impossible, but merely that chemical development might be impossible. To realize the distinction it will be necessary to consider what an invisible ink is and in what development consists. Invisible inks, with a few exceptions, which will be referred to later, generally consist of water containing some chemical ingredient in solution, and such inks are invisible merely because they are colourless or practically colourless. Chemical development consists in so changing the nature of the ink that it becomes coloured and therefore visible. This change may be brought about by light, by heat or by appropriate chemical reagents. But the act of writing, whether the ink be invisible or not, does more than merely place the writing fluid on the paper. In the process the surface of the pa2)er, the special physical condition of which is produced by pressure and heat, generally becomes scratched by the writing instrument, and is also partly destroyed, or at least affected to some extent, by the solution used, and even writing made wdth distilled water and a soft brush affects the pajDer and can therefore be developed. In some cases too the solution may possibly act upon the sizing or the loading material of the paper. The result of the alteration of the surface is to make the paper more absorbent, and hence if a coloured solution be applied, the colour is retained mechanically to a greater 94 LEGAL CHEMISTRY extent in those parts where the writing occurs than on the rest of the paper, and the writing therefore becomes visible. Coloured powders also adhere more firmly to those places where the surface of the paper has been affected by the writing. The application of coloured solutions or coloured powders therefore constitutes a valuable mechanical method for developing invisible inks. Hiff When secret wTiting is suspected both chemical and mechanical development should be tried, beginning with the latter. The value of secret writing is not that it cannot be developed unless the nature of the ink is known and the correct chemical developer applied, for most invisible inks can readily be developed by mechanical methods, but the value consists in the fact that secret writing will probably escape detection unless suspicion is aroused and special search made. Before applying any method of development, however, the suspected document should be carefully examined in a good light, both in the ordinary way by reflected light and also by transmitted light. When making the examination by reflected light, the light should be allowed to fall both directly on the paper, and for this purpose a strong light is required, and also obliquely, and for this the light should not be too strong. When glazed paper is used the presence of secret writing can practically always be detected by careful inspection, no matter what the nature of the ink is, unless after the writing is finished, the paper is treated in a special manner, which is very simple and not generally known, but which cannot be divulged. This treatment does not affect subse- quent chemical development of the ink but reduces the efficacy of some forms of mechanical development or prevents it altogether. An examination for invisible ink by means of a lens or microscope is not of much value and is seldom necessary. The methods of development already referred to will now be described. Light. — Exposure to light develops silver salts, and also dyes, such as fuchsine, which have been decolorized, but DOCUMENTS 95 in the latter case it is the air and not the liglit whieli brings about the development, the process being one of oxidation. Heat. — This develops writing made with such fluids as dilute sulphuric acid, urine, milk, lemon juice and other fruit and vegetable juices and solutions of sugar, copper salts and cobalt salts. The most satisfactory manner to apply this test is by means of a carefully-regulated air oven, but a hot iron also gives good results, an electrically-heated one being the best. Documents on which there are wax seal impressions should never be heated in an oven, but always ironed, the wax of course being avoided : documents made of celluloid, which is sometimes used for Christmas, New Year and birthday cards, should not be heated, since this material unless specially prepared is very inflam- mable. Chemical Reagents. — The chemical compounds which might be required as developers are innumerable and only a few general reagents of difterent classes can be tried. The following named are the best : — Ammonia. — For substances, such as phenol-phthalein, which form coloured compounds with an alkali and for salts, such as those of copper, which form coloured hydrates. Ammonium Sulphide. — For the salts of metals which form coloured sulphides, such as tin, copper, iron, cobalt and nickel. Ferric Chloride. — For tannic acid, potassium ferro- cyanide ^ and some organic compounds. Ferrous Sulphate. — For tannic acid and potassium ferricyanide. Potassium Ferrocyanide and Potassium Ferricyanide. — For ferric and ferrous salts respectively. Tannic Acid. — For iron salts generally. Iodine. — This may be employed either in solution or as vapour and develops a large number of invisible inks. Iodine sometimes acts as a chemical developer, as for instance with starch, but more often merely mechanically. ' Potassimn ferrocyanide is most unsatisfactory for secret writing, since it is liable to decompose slowly on the paper and to become visible. 90 LEGAL CHEMISTRY Tlic above reagents, with the exception of iodine, are best applied by means of a soft brush, a stroke being made diagonally across the paper as a preliminary trial. Iodine solution is best apj^lied with a hard flat brush. When using iodine vapour a few crystals of iodine are placed at the bottom of a glass vessel, such as a large beaker or dish, in which the susjjected document is also placed, and the vessel is then covered and gently heated. Although it is possible to employ all the various com- pounds above-mentioned as secret inks, it is doubtful whether more than a very few are actually used. The author's experience includes the use of onion juice, of a lead salt and of several different organic compounds, for one of which there was a simple chemical developer and for another a very complex developer consisting of two solutions. All these inks, however, could be developed by coloured powders or better by coloured solutions. Coloured Powders. — The powder should either be sprinkled or sj)rayed on the document or applied by means of a soft brush, the latter method being the best. Almost any coloured powder, even dust or ashes, will do if it is in a sufficient!}^ fine state of division, but graphite and iron oxide (such as jeweller's rouge) are the best. Coloured powxlers develop most invisible inks including water, saliva, urine, milk, sugar, salt, lemon juice, and most chemical reagents. Coloured Solutions. — The use of such a solution appears to have been first suggested by Forgeot in 1891 for the purpose of developing invisible finger prints on paper, and he em})loyed ordinary writing ink.^ The modification of this test suggested by Nicefero,- also for developing finger prints on paj^er, is very satisfactory, not only for that purpose, but also for developing secret writing. It consists in diluting ordinary blue-black writing ink with water, applying this to the paper by means of a brush and then washing off the excess. Almost any coloured water solution however will ■ Des empreintes digitales, etudiee au point de vue medico -judi - ciaire, R. Forgeot, These de Lyon, 1801. • La Police et TEnquete Judiciaire Scientifiques, A. Nicefero, Paris. DOCUMENTS 97 do, thus red ink may be used or a solution of any aniline colour. Although the finger print or the secret writing is developed without the subsequent washing of the paper, this latter is essential if the best results are to be obtained. A strong solution of some water soluble blue, such as methlyene blue, will be found to be very satisfactory. This is painted on the paper by means of a hard flat brush, and the paper is then immediately put under a tap and rinsed well with running water. When dealing with a large sheet of paper, or with one that requires treatment on both sides, it will generally be found advantageous to put the paper bodily in the solution instead of using a brush. The procedure followed is identical with that employed for developing photo- graphs, the dish containing the developer being rocked from side to side. This method develops a very large proportion of invisible inks and is one of the most satisfactory for general use. A solution of an aniline dye in alcohol will answer the same purpose. ^ In this case the paper is allowed to remain several minutes in a dilute alcoholic solution of the dye and is then rinsed with alcohol. This alternative method might prove useful in case there was any writing on the paper, other than the invisible ink, which was soluble in water but not in alcohol, and which it was desired to retain. Most methods of developing invisible ink disfigure the paper, but in some cases, from his knowledge of the compo- sition of the developer, a chemist can decolourize it after it has been applied or can decolourize the compound formed, and so remove all traces of the development. - Dilute solutions of oil in alcohol or other solvent are I An alcoholic solution of an aniline colour is sometimes used to develop finger prints on glass. Manuel de Police Scientific, R. A. Reiss. ^ It has been stated in the public press that during the war the Censor's Department employed a developer for the detection of secret writing of such a natvire that after use it could be chemically reinoved without leaving any visible signs that the document had been tested. It would be impossible, however, to eliminate entirely the evidence of the use of this or of any other developer, and although altered in character and no longer visible, the developer could always be detected by suitable chemical means. 8 98 LEGAL CHEMISTRY sometimes employed as invisible inks, and hence form an exception to the rule that invisible inks are water solutions. The oil used is generally castor oil, which is one of the very few fixed oils soluble in alcohol, but essential oils could also be employed. These latter however are most unsatisfactory since they entirely disappear in time by evaporation. Such inks may be develojjed by soaking the paper in water, when the writing becomes translucent and readily visible. Occasionally, however, the secret writing is of the nature of an artificial water-mark which is made while the paj^er is wet by placing over it a dry sheet and writing on this latter with a hard and blunt pointed pencil or similar instru- ment, writing made in this way being invisible when the paper is dry, but can be seen plainly if examined by trans- mitted light when the paper is wet, and hence can be deve- loped by soaking the paper in water. A solution of bismuth nitrate in dilute nitric acid, which is sometimes recommended for use as invisible ink, can also be develoj^ed by water. Both dilute nitric acid and dilute hydrochloric acid can also be used and can be developed in the same way, the writing when wet becoming translucent and visible. It should not be forgotten that all seemingly blank pieces of paper, even though sent as letters through the post, do not necessarily bear invisible writing, a blank sheet being sometimes placed round a letter to prevent the writing showing through the envelope. Sometimes, too, a sheet of blank paper is sent as a specimen or to supply writing paper to some one likely to be without, or as a pre-arranged signal, or eveii as a practical joke. Writing which has been developed and is still not very distinct, often gives excellent results when photographed. In some instances the manner in which a sheet of paper is doubled or creased constitutes a code or signal : the water- mark too may be specially prepared and may convey a message or have a secret meaning. In the case of letters sent through the post, the inside of the envelope and underneath the postage stamp should be specially examined. Even the position of the stamps on the envelope may be a signal. In one case part of the lettering on the postage stamp had been obliterated leaving DOCUMENTS 99 the figure indicating the value of the stamp to serve as part of a message. Some of the substances used during the war of 1914-18 as invisible ink were articles of everyday use which could be bought openly and carried without suspicion, others were uncommon organic compounds which were intended to be developed with a developer of the nature of some of those employed in photography, but it was found that these could also be developed by mechanical methods. Some ingenious methods of carrying and sending supjDlies of ink were dis- covered, but natural^ cannot be disclosed. Impressions of Seals. In the East it is a very common practice for names to be impressed on documents by means of engraved metal seals instead of the documents being signed in the Western manner. This practice is not confined to those who are illiterate, but is very general, and even in Government offices the less important documents are frequently sealed. The seal is inked as a rule from a pad, a coloured aniline ink being generally used. Such seal impressions when made ^\dth aniline ink can readily be transferred from one docu- ment to another, and such transfers cannot easilj^ be detected. The various methods of transfer mentioned in books dealing with this subject yield very poor results, and much better ones are available, though it is not advisable to describe them. The practice of using an aniline ink for the seal on an important document is therefore most dangerous. Aniline inks, too, are unsuitable for such a purpose on account of the ease with which they fade on exjDosure. Oil carbon inks are much safer, and with a suitable ink, transfers cannot be obtained when the impression is more than a few days old. The seals themselves are sometimes counterfeited, but im- pressions made with forged seals are generally easily detected when sharp, though less easily recognized when the impression is a poor one, wliich unfortunately is very frequently the case. It should not be forgotten, however, that in cases where the same seal is used, it is sometimes cleaner orj better or more uniformly inked than at other times, and' so the impression may appear superficially different. Sometimes, 100 LEGAL CHEMISTRY too. the ink spreads on one side of a seal in such a way as to cause the impression to appear larger and of a somewhat different shape than usual. Before it can be stated whether a giv^en impression is a forgery or not it is necessary to compare it carefully with an impression of the genuine seal. For measuring purposes a thin glass or celluloid plate ruled in small squares which can be placed over the impression to be compared will be found very useful. Much may be done by direct comparison, but indirect methods in which the impressions to be com- pared are photographically enlarged are much more satis- factory. A very good yet simple method of carrying out a comparison of this sort is to put the documents side by side in a photographic frame, and by means of an enlarging camera to obtain enlarged images on a ground glass plate. Tracing cloth is then placed touching the glass plate and is held in position by a wooden framework or other device, and the enlarged images of the impressions are traced by hand wdth Indian ink directly on to the cloth. These tracings are then superimposed one on the other and examined by transmitted light. If the case is one likel}' to be brought into Court the best method is to make photographic enlarge- ments, and from the negatives to prepare positives on glass which can be produced in Court and directly compared by superimposing one on the other. 8ince seal impressions are frequently made in coloured ink it is necessary in such cases to use special orthochromatic plates and light filters in order to obtain satisfactory'- photographs. By means of a chemical and microscopical examination it is sometimes possible to state whether two or more seal impressions having the same superficial appearance and colour have been made with the same ink or not, but as a rule neither the age nor the relative age of the ink on a seal impression can be determined from chemical evidence, since the ink is generally either carbon or an aniline colour. The date when seal impressions in ink were first used on documents in Egypt is not known, but a seal impression in black ink has been noticed on a document at the Govern- ment Archives dated 1184 a.ii. (a.d. 1770) and seal impres- sions in green ink were found on a number of documents DOCUMEN^C^;^ 101 dated respectively 1284, 1286/1287^{lT),d; i^SS '4.Hr,;(L'i. 1867, 1869, 1870 and 1871). In connection with seal impressions, attention may be called to the results of the examination of a number of mediaeval English wax seal impressions by Dobbie and Fox.^ The dates of the impressions ranged from the thirteenth to the beginning of the sixteenth century. The seals were found to consist of beeswax alone, or of beeswax mixed with resin in various proportions. In two cases the resin was colophony, but in the other cases it could not be identified. The red seal impressions were coloured with vermilion, the green with verdigris, the brown and black with verdigris and organic matter. The beeswax which formed the sole constituent of an impression of the Great Seal of 1350 was practically unaltered in chemical and physical properties. A thirteenth-century seal impression, which consisted of beeswax alone, had been attacked by mould and had become flaky and disintegrated. For the purpose of examining documents a counting glass with a field a square inch in size, such as is used in the cotton trade, will be found a very satisfactory form of lens, since the field is large and the glass, being in a framework, can be placed on the document, thus leaving both hands free. For a microscope, Osborn recommends the Bausch and Lomb special document microscope, but the " Process " microscope made by R. & J. Beck, Ltd., will be found a very useful instrument, and it has the advantage of being cheap. This microscope is specially made for the examination of lithographic stones and zinc and aluminium plates, and has no stage, the objective being at the end of a long arm which reaches over the document, which therefore can be examined without folding. BOOKS OF REFERENCE. Questioned Documents. Albert S. Osborn. Rochester, N.Y., 1910. Bibliotics. Persifor Frazer. Philadelphia, 1901. The Detection of Forgery. Blackburn d- Caddell. London, 1909. La Photographie Judiciaire. R. A. Reiss. Paris, 1903. Inks. C. Ainsworth Mitchell, ancl^. C. Hepuorth. London, 1910. ' J. Cheyn. Soc, March, 1914, p. 795. 102 LE(^AL CHEMISTRY Copying Ink Pencils afid ,"thc' 'lOKaminatiou of their Pigments in Writing. C. A. Mitchell, Analyst. 1917. Ciiniinal Investigation. Hans Gross. Trans. Madras, 1900. Circumstantial Evidence. Wills. Loiidon, 1912. Chaji. IV, Sections 3 and 4. DUST AND DIRT Dirt has been described as " matter in the wrong place," and it is the business of the cheraico-legal expert to discover the place to which this matter, when found in connection with a crime, rightly belongs, and in so doing he may provide a valuable clue to the identity of the criminal. Dust and dirt should be examined microscopically in the first instance, but a chemical analysis should also be made if the amount of material available will allow, and for this purpose micro-chemical tests will frequently be found useful. The following case may be quoted : — A safe had been robbed, the door having been bored through, and some of the finely powdered material used as a fireproof packing between the two walls of the safe was scattered about the room. This was found to be entirfely mineral, to be free from fibres and organic matter, and to contain a number of small rounded particles of various colours, which manifestly had been fused and which were very characteristic. Some dust found on the clothes and between the fingers of two persons suspected of the robbery, was identified as consisting of this same material and the men were convicted. A careful examination therefore by a chemist of the dust and dirt found on clotliing in criminal cases may be useful. In another case the fact that the finger nails of a certain man, who was suspected of being concerned in the making of a gelignite bomb, did not show any signs of gelignite when examined, proved negative evidence in the man's favour. The sand occurring in different localities in Egypt differs very considerably in composition, thus for example the river sand is siliceous, the desert sand frequently calcareous, the DUST AND DIRT 103 t sand on the shore at Alexandria and Port Said is calcareous with numerous shell fragments, while the sand at Aswan is largely composed of granite detritus, and dune sand is very characteristic. An expert examination of sand found in connection with a crime therefore may prove very useful, as the following cases show. Some sand found in the pockets of the waistcoat mentioned in connection with the subjects Clothing, and Stains and Marks respectively, proved to be extremely fine quartz sand with well-rounded grains of uniform size similar to dune sand, and from this it was concluded that the wearer of the waistcoat had been in a locality where there were sand dunes. In another case, sand taken from the barrel of a gun was proved to be identical with the sand from the place where a crime had been committed, and of which the owner of the gun was suspected. The value of this fact, however, was discounted by the further fact that similar sand could be found in many other localities, but in connection with the particular circumstances of the case the fact was of value. * In another case, sand taken from the stomach and duodenum of a drowned man was examined. As the quantity of material available was very small indeed, only a micro- scopical examination was possible. The sand was found to consist essentially of colourless grains, all very angular and many having definite crystalline form which proved to be selenite : there was an absence of quartz, but on one slide there was part of a diatom. The presence of selenite in large proportion and the absence of quartz seemed to preclude the Nile valley and suggested the northern shores of Egypt. It was probable therefore that the man was drowned off the coast where his body was found and that he had not been transported there after having been killed elsewhere, as was at first thought might possibly have been the case. In several cases of counterfeit coining the fact that the working parts of machines seized on the premises of the accused persons were well oiled and were free from accumu- lated dust and dirt has made it very probable that these machines had been recently used. In another case of coining 104 LEGAL CIIEAnSTRY * a tiny particle of metal, similar in composition to that used for making the counterfeit coins, was found on a file in the house of one of the accused persons. When dealing with the subject of Damage to Crops it was exjDlained that dust on certain market garden crops growing on land adjoining a tarred road was found on examination to contain tar, and hence could be recognized as having certainly been derived from the road in question. A proof of this nature, that certain dust had come from a particular road, might be very useful in criminal investi- gation. BOOKS OF REFERENCE. Criminal Investigation. Hans Gross. Trans. Madras, 1906. A Manual of Microchemical Analysis. H. Behrens. London, 1894. Elementary Chemical Microscopy. E. M. Chamot. New York, 1916. EXPLOSIVES AND EXPLOSIONS Questions having reference to explosives submitted to the chemico-legal expert generally concern such articles as high explosives, bombs, infernal machines, or cartridges, used or intended to be used, for criminal purposes. Sometimes, however, the chemist may be consulted on questions arising out of the manufacture, transport or storage of explosive materials, or in connection with explosions in order that the cause may be ascertained. The examination of bombs and infernal macliines is always attended with danger, and all possible })recautions should be taken to avoid accidents. The best preliminary examin- ation of a suspected infernal machine is to have a radiograph taken, when the nature and disposition of the contents become plainly visible. Several instructive reproductions of such radiographs are given by Brouardel in his well-known book on Explosives and Explosions. Several ways of opening infernal machines are mentioned in various books,' but the author has had no personal experi- > Traite dc Chimie Legale, E. Barillot, Faris, 1894. EXPLOSIVES AND EXPLOSIONS 105 ence of any of them. One of the methods is very ingenious, but is only applicable to metal recef)tacles which are closed by means of solder. This method consists in fixing the infernal machine in a deep stone basin into which mercury is poured until the basin is full, when the sides, bottom and cover of the receptacle fall apart, the solder being dissolved by the mercury. Another method recommended when deal- ing with metal vessels having a cover simply fixed on, but not soldered or rivetted, is to place the vessel between two vertical supports, one of which is fixed and the other movable, and the latter, being operated from a distance, is then gradually pressed against the vessel in order to deform it, when the cover becomes loosened and may easily be removed. Bombs are sometimes made from gelignite taken from ordinary gelignite cartridges and massed together. Several examples of this have been investigated, one being the bomb which was thrown at H.H. the late Sultan Hussein of Egyj)t in 1915, and which fortunately did not explode. This bomb consisted of a mass of gelignite weighing 338 grams into which were inserted a large number of the iron studs used for fastening the bands of cotton bales, as also a detonator and fuse, the whole being wrapped in newspaper and then in thin pliable leather to make it resemble a harmless ball. The failure of this bomb to explode was due to the fact that a small amount of sawdust had been left in the detonator, ^ and although the fuse burnt through, the amount of sawdust was sufficient to prevent the flame from reaching the ful- minate. A second and similar bomb was found in the room from the window of which the first was thrown, but in this case there was no sawdust in the detonator, and in all proba- bility therefore the second bomb would have exploded had it been used instead of the first. In all cases bombs should be weighed, measured and carefully described, and the explosive material should be weighed and analysed. In the case just mentioned, the composition and weight of the gelignite made it probable that it had been obtained by massing together eight of the large size of Nobel's cartridges, and pieces of parchment paper, ' Detonators are usually packed in sawdust. 100 LEGAL CIIKMLSTRY such as is used for wrapping gelignite cartridges, remained embedded in the mass : these were all cut out and carefully examined, but unfortunately there was no inscription on them. The exact size of the bomb proved of imjjortance, since one of the questions raised by the defence during the trial was whether it Mas possible to pass the bomb through a certain opening in a shutter, it having been proved that the shutters of the window from which the bomb was stated to have been thrown were partially closed. Gelignite and similar explosive material should alwaj's be cut with a horn or bone knife and never with steel, and care should be taken not to handle an explosive containing nitro-glycerine more than is absolutely necessary, otherwise the very unpleasant symptoms of nitro-glycerine poisoning (violent headache, profuse perspiration, vomiting and diarrhoea) will probably be experienced. One difficulty the expert will have in dealing with ex- plosives is that of getting rid of the residues of the samples. In the case of materials such as blasting gelatine, gelignite, dynamite and cordite, the materials should be placed in an open space, saturated with kerosene and burned, the fire being started by means of a fuse, care being taken so to arrange and light the train that the flame will travel against the wind. Black powder and potassium chlorate explosives may be destroyed by dissolving out the soluble ingredients with water. Nitro-glycerine may be destroyed by means of an alcoholic solution of caustic soda, but is better burned in small C[uantities at a time. Detonators cannot be destroyed with safety and therefore should be taken out to sea and thrown into deep water. ■•■ In several cases connected with explosives which have been investigated, the size, weight and composition of blasting gelatine and dynamite proved that these materials were not of Nobel's manufacture, which alone can legally be imported into Egj^pt, and therefore that they were contraband. In other cases the composition of the charge of rifle cartridges has proved useful in tracing their origin. In one case, a large dynamite cartridge, which manifestly had been cylin- drical at one time and had become somewhat flattened, was examined, and it was found that there was no nitroglycerine EXPLOSIVES AND EXPLOSIONS 107 at all present, and that the material contained a little chloride and a trace of sulphate, and it was concluded that the cartridge had been immersed for a considerable period in salt water, during which time the nitro -glycerine had escaped, and that while wet the cartridge had been subjected to pressure. Contraband blasting powder is made to some extent in Egypt, and is sometimes submitted for analysis. The material however is so crudely made, and differs so much from the genuine powder in appearance, that an analysis is hardly necessary. To make this contraband powder, sodium nitrate which is largely employed in Egypt for agricultural purposes, and therefore is easily obtainable, is used in place of potassium nitrate. In America, however, this substi- tution is recognized and large quantities of blasting powder are made with sodium nitrate. Sodium nitrate too is now sometimes used in England to replace the potassium salt in ordinary gunpowder. None of the cases concerning explosions submitted have been of sufficient interest to merit detailed description, though several will be mentioned to show the nature of such cases. One involved the testing of the stability of the explosive (ballistite) in a shell which had escaped destruction during an explosion at an ammunition store, as a consequence of which one man had been killed and certain damage to property had occurred, for which claims for compensation were made. Another case necessitated an opinion on the facts elicited at an enquiry concerning an explosion at a store containing high explosives (blasting gelatine and gelignite) used for mining and quarrying. The cause of the accident in both instances was undoubtedly spontaneous decomposition due to the fact that the explosives in question had been stored in a hot climate for several years, in one case partly in the Sudan and partly in Cairo, and in the other case chiefly in Upper Egypt. In a third case the gelignite charge of some bombs made locally during the war of 1914-18 was found to have deteriorated so much after about two years storage as to have become unsafe. The gelignite was packed in an inner zinc cylinder enclosed in a brass case, and the former had 108 LEGAJ. CHEMISTRY become very corroded, and several small explosions took place on handling the outer brass cases after the inner cylinder had been removed. As the bombs were manifestly unsafe they were destroyed by throwing them into the sea. Several cases have been investigated in which iron drums containing strong sulphuric acid have exploded and caused injury to men either handling them or who were in the vicinity at the time. Although the acid was of high strength (92 and 93 per cent.) and fairly pure, and although no signs of special corrosion could be found in the drums, the presence of a large proportion of ferrous sulphate in the acid w'as con- clusive proof that considerable action of the acid upon the iron had taken place. Doubtless a contributory cause was the high summer temperature in Egypt, and in some instances the drums had been left exposed to the sun. In cases of this nature the expert should not be satisfied with the examin- ation of any small sample of the acid forwarded to him, as this may not be representative, owing to ferrous sulphate having settled out to the bottom of the drum, but he should have a sample of the acid from both the top and bottom of the drum, two samples, one from the top and one from the bottom being preferable to one mixed samiile. BOOKS OF REFERENCE. Les Explosifs et les Explosions. P. Brouardel. Paris, 1897. Annual Reports of H.M. Inspectors of Explosives. London. Annual Reports of the Chief Inspector of the Bvireau for the Safe Transportation of Explosi\es and other Dangerous Articles. New York. FIBRES Fibres may be either animal or vegetable. If in the form of a few small loose particles the recognition is necessarily microscopical, but if in the shape of a woven material the recognition may be partly microscopical and partly chemical. Loose fibres only will be considered here, woven cloth being dealt with under Textile Fabrics. FIBRES 109 There are few subjects that will repay the chemico-legal expert better than a study of the microscopical appearance of fibres, and certainty of recognition can only be attained by long practice. The published illustrations of the structure of fibres, although sometimes helpful, are on the whole very disappointing, and anyone relying ujDon a book illustration and not on his own experience is apt to be misled. Th only certain method of recognition is by means of carefu comparison with other fibres known to be genuine. In th case of animal fibres it should not be forgotten that haii|/' from different parts of the body of the same animal may var; ' very considerably, most animals producing two kinds oj hair, a long, coarse, stiff hair termed " beard hair " and shorter, finer, softer, and more curly hair called " woollfl hair," and these differ not only in the properties mentioned!| but also with respect to the presence or absence of scales! and medulla. The expert should make himself acquainted not only with the microscopical appearance of the hair of the ordinary common animals and of fibres used for woven fabrics, but he should also be able to recognize most of the principal textile fibres of commerce, such for example as those em- ployed for paper, cordage, brushes, mats, hats and in the fur industry. It is a comparatively simple matter to distinguish hair from other fibres and human hair from animal hair, and [ with exjDerience it is not difficult to differentiate between the hair of different kinds of animals. It is stated too that it is even possible to determine the region of the human body from which a particular specimen of hair has been derived. Sometimes it is useful to know whether certain hair has fallen out naturally or has been forcibly torn out, and this I may be determined by a careful examination of the roots. If the root is small and club-shaped with a rounded ex- tremity and smooth surface, the hair has probably fallen out, whereas if the root possesses an irregular surface and adherent root-sheaths, then the hair has been plucked out. The best way of treating hair for microscopical examina- ^ 110 LEGAL CHEMISTRY tion is to soak it in ether or turpentine to remove fatty matter and after drying to mount it in Canada balsam or to examine it in water. If the hair is dirty, as may sometimes be the case, it should be washed in water and dried before treatment with ether or turpentine. In this connection the following note on human hair may be of interest, since the colour of the hair of an exhumed body may possibly be an important factor in the identification . of the j^erson buried. Hair itself is very resistant to putre- ; faction, but it is generally stated that the colour is not so/ resistant. This however requires qualification, and it willi be shown that under certain conditions the colour of human hair may remain unchanged for several thousands of years. It is also sometimes stated that all hair eventually becomes red, and the red colour of the hair of some old Egyptian bodies is pointed to as proof of this. Wilkinson would seem to support this view, for he writes ^ *' Many of the mummies of women have been found with the hair perfectly preserved, plaited in the manner I have mentioned ; the only alteration in its appearance being the change of its black huey which became reddened by exposure to great heat during the process of embalming." ^ As there seemed to be some difference of opinion about the matter it was thought that it might be useful to collect as many definite facts as possible concerning the colour of the hair of mummies and other bodies, and the following have been noted. During the Archaeological Survey of Nubia a very large number of bodies were carefully examined and described by Professor G. Elliot Smith and Dr. F. Wood Jones. 3 These bodies belonged to all periods varying from Predynastic to ' The Ancient Egyptians, Sir J. Gardner Wilkinson, F.R.S., London, 1890. Vol. II, p. 335. * There Ls no proof tliat the body was subjected to great heat during the process of embalming. Doubtless the resinous material employed as a preservative, especially that introduced into the skull was applied in a molten or semi-molten condition, but this does not require great heat. 3 The Archopological Survey of Xul)ia. Rojioit for 1007-8, Vol. II. Report on the Human Remains by Prof. G. Elliot Smith, F.R.S. and Dr. F. Wood Jo7ies, Cairo, 1910. FIBRPZS 111 Early Christian. In the published report reference is made to the hair in 128 different cases, and the following tabular statement shows the results : — Hair from Nubian Graves. Colour not stated 43 Black 4G Brown 8 Dark 1 White 16 Black with white 3 Brown with white 3 Dark with white 2 Grey 6 Total 128 In eight of the cases in which the colour is not given the hair is described as being " typically negro," in two other cases as "typically negroid," in one case "woolly negroid," and in one case " woolly." None of these twelve cases there- fore are likely to have been red. In seven of the cases of white hair the person is specifically called " old " : in one instance however the person was apparently young, since a suggestion is made that possibly the white colour of the hair was due to post-mortem bleaching caused by the salt used in embalming. In two of the cases of brown hair the description given is " now brown," as though it was desired to suggest that brown had not been the original colour. In no single case is the hair described as red or even reddish. In the catalogue of royal mummies in the Cairo Museum, Professor Elliot Smith describes fifty mummies. ^ I Catalogue General des Antiquites Egyptiennes du Museo du Caire. The Royal Mummies. G. Elliot Smith, FM-ti., Le Caire, 1912. • 112 LEGAL CHEMISTRY The results so far as the hair is concerned are as follows : — Hair of Royal Mummies. Colour not stated 26 Black 1 Dark l)iown 4 Bro\\ii 2 Dark reddish-biown 1 Reddish-brown 2 Yellow 1 Black with grey 1 Dark brown with grey 1 Grey 2 Brown with white 1 White 7 Stained a brilliant reddish colour .... 1 ' Total 50 In addition to the above there were three wigs, all of which were brown. Two specimens of hair from mummies were examined for the late Sir M. Armand Ruffer, one of which was of a very light brown colour, and the other black. The former belonged to the twentieth dynasty and the second could not be dated. The light brown hair was matted together with a paste that proved on analysis to be a mixture of natron and soap,- but whether the natron had affected the colour of the hair in any way cannot be stated, though this seems probable. The hair of all the human and animal mummies, as well as of all the wigs, found exposed in the Cairo Museum have also been examined. The results are shown on the next page. ' Interplaited with strands of hair of a black colour. 2 The soap was probably a product of the action of the natron on fatty material with which it had hvvn mixed. FIBRES 113 Hair of Human Mummies in Museum. Black, curly 1 Brown 2 Light brown 1 Dark 1 Flaxen 2 Impossible to determine whether any hair at all without closer inspection : certainly no red hair . .' t) Total 13 Hair of Ape Mummies in Museum. Dark 2 Dark brown 1 Brown 3 Total 6 Wigs in Museum. i Black 2 Very dark brown 4 Brown "1 Total 10 In view of the foregoing facts, therefore, there can be no doubt whatever that under Egyptian conditions of burial the hair certainly does not always become red even after several thousands of years, and it seems very doubtful whether it ever undergoes such a change ; in the one case where the hair is red Professor Elliot Smith specially I Inside one of the wigs there was some fibre which resembled coco-nut fibre in appearance, and the colour of this had a slight sugges- tion of red. 9 114 LEGAL CHEMISTRY states that it is stained, and suggests henna, which is still used for this purpose in Egypt, as the dye probably employed. The following cases, although dealt Mitli more fully else- where, may be mentioned as illustrations of the value of the recognition of fibres in criminal cases. 1. In connection with a question which concerned the identity of several pieces of cotton material, one found wrapped round the body of a murdered woman, and others taken from the house of one of the accused persons, it was found that each of the pieces of cloth had attached to it a few threads of the material with which it had been sewn to something else. All these threads were linen, a somewhat unusual material with wdiich to sew thin cotton cloth, and all were of the same diameter and general appearance. 2. On the wax seal impression on an envelope which figured in a case of robbery a few tiny black-looking fibres were found which proved to be dark blue wool and to corre- spond exactly with the material of the frayed edge of the turned up sleeve of the coat of one of the persons employed l)y the firm from whom the robbery had taken place. This man, however, had possibly helped to seal up the enveloi^e originally. BOOKS OF REFERENCE. Fibres used in Textile and Allied Industries. Mitchell preparation of food. In Egypt butter fat is called samn (butter being zibda), and in India ghee. FOODS AND DRUGS 139 Drugs. The analysis of drugs, with which may be included medicines, although not without difficulty, is not more difficult than many other kinds of analysis the chemist is called upon to undertake. One essential for the recognition of vegetable drugs is a collection of materia medica specimens that can be relied upon. The examination of fragments of vegetable tissue and seeds found in the stomach, intestines or vomit in cases of suspected poisoning is sometimes required. The recognition of such materials is always difficult, and needs considerable experience, and comparison with known specimens is always advisable. Analyst's Certificate. The Sale of Food and Drugs Act 1875 prescribes in the Schedule the form of certificate the analyst shall use when reporting samples taken under the Act. This form is as follows : — To I, the undersigned, public analyst for the do hereby certify that I received on the day of 19.... from a sample of for analysis (which then weighed ) and have analysed the same, and declare the result of my analysis to be as follows : — I am of opinion that the same is a sample of genuine or I am of opinion that the said sample contained the parts as under, or the percentage of foreign ingredients as under. Observations. ^ I Here the analyst may insert at his discretion his opinion as to whether the mixture (if any) was for the purpose of rendering the 140 LEGAL CHEMISTRY When the article analysed iiroves to be genuine, no great objection can be taken to the form of the certificate, but in the case of articles found to be not genuine the wording of the certificate is most unsatisfactory. Thus, in many instances it is absolutely impossible to state the percentage of foreign ingredients present in a sample, since this cannot be determined, as, for examj)le, in the case of alcoholic liquors, where the only adulterant of which the percentage amount present can be stated with any certainty is water. The fact that the Food and Drugs Act specifically states that the analyst may show on his certificate " whether the ingredients or materials mixed are or are not injurious to health " is worthy of note, since it is sometimes contended that a chemist should not venture to give any opinion on such matters, but should leave them entirely to the medical man. BOOKS OF REFERENCE. Bell's Sale of Food and Drugs Act. C. F. Lloyd. London, 1910. P'orensic Chemistry and Chemical Evidence. W. Ja/jo. Lontlon, 1009. GOLD AND SILVER WARES The assay of gold and silver presents no difficult}'. Some- times however questions arise concerning the method of sampling employed. No general rules can be laid down, and the assayer must be guided by circumstances and experi- ence. In most cases of gold wares, however, the surface, article portable or palatable, or of preserving it, or of improving the appearance, or was unavoidable, or may state whether in excess of what is ordinary or otherwise, and whether the ingredients or materials mixed are or are not injurious to health. In the case of a certificate regarding milk, butter or any article liable to decomposition, the analyst shall specially report whether any change has taken place in the constitution of the article that would interfere with the analysis. GOLD AND SILVER WARES 141 which is richer than the metal below, must be removed, by a preliminary scraping before the sample is taken, otherwise a considerable error is introduced. When dealing with finished jewellery or works of art which cannot be defaced, the only method of assay avail- able is by the touchstone, with which an experienced assayer can determine the fineness of a gold object to within about half a carat. Although generally used only for gold, the touchstone can also be employed for silver, and a close determination of the fineness of silver articles may be made by this means. I On several occasions the author has made assays in con- nection with prosecutions in which a jeweller has been accused of selling gold articles wrongly marked, and in all instances both the accused and his lawyer, by order of the Court, were present throughout the assay. This is most unsatisfactory, and in a case like that of a complicated chemical analysis such a proceeding would be open to very grave objections. In the cases referred to the method of assay was explained and any suggestions or complaints were considered, but not necessarily followed, these however being mentioned in the report, as also the reason for following or disregarding them. Forged hall-marks are occasionally met with. The for- gery may be proved by careful comparison with genuine marks and may be demonstrated in Court by means of enlarged photographs. The punches themselves, if these are seized, will generally be found to differ both in size and shape from the genuine ones. The approximate date of manufacture of gold and silver wares may sometimes be determined from the hall-mark, even in the absence of any special date mark, since the designs of hall-marks are occasionally varied, and the date of the change may be susceptible of proof. I "Assay of Silver by Means of the Touchstone." A. Steinmann, Analyst, 1911, 372. 142 LEGAL CHEMISTRY HASHISH Hashish is the Arabic term for grass, weed or herbage gener- ally, but in addition to this meaning the word has acquired a special and narrower signification, and is applied to a particular plant, the Indian hemp {Cannabis indica),^ and to preparations made from it. As ordinarily used in Egypt, however, the word hashish means the resinous material from the plant, containing a certain amount of leaf tissue and mineral matter,- the whole comjDressed into a hard cake. Hashish as thus defined corresponds to the Indian " Charas." The Indian " Bhang " and " Ganja " are also derived from hemp). Bhang is generally stated to consist of the dried and broken leaves and small stalks of the plant, together with a few fruits, the whole in the form of a coarse powder, while Ganja is stated to be the flowering and fruiting tops of the female jolant compressed into bundles. Some Ganja however examined by the writer was similar to what is usually described as Bhang, and consisted of the extreme tips of the plant with the minimum of stalk, a few fruits and some small flower buds. Hashish is used in three different ways, and may be smoked, eaten or drunk, smoking and eating however being the usual modes of consumption. When smoked, the drug is mixed with tobacco and used either in a water pipe or in the form of cigarettes. In some samples of cigarettes examined the amount of hashish varied from seven to sixteen per cent, of the net weight of the tobacco. When present in cigarettes hashish is readily detected, since it is introduced either in the form of small pellets or more generally in thin strips. If no visible hashish is found, the tobacco itself ' Cannabis indica is idontical botanically with the ordinary liemp, C. saliva of temperate climates. - The mineral matter in various samples examined ranged from 24 to 36 per cent. This large amount of mineral matter does not seem to indicate adulteration, but jirobably originates largelj^ in the dust accumulated on the plant during growth, together with additional dust and dirt that gain access during packing, the sticky nature of the resinous secretion being responsible for the largo amount that adheres. HASHISH 143 should be tested by Beam's test, since it is quite con- ceivable that it might have been soaked in an alcoholic solution of hashish. The author has never actually known a case where this particular method of introducing hashish into tobacco has been employed, but he once examined a strong alcoholic solution of hashish which was seized by the Customs, and which could have been used for such a purpose. For eating, hashish is mixed with spices and made into a paste with sugar, honey, molasses or fat, or it is introduced into sweetmeats. The paste is taken in the form of pills. Sometimes various drugs such as opium, powdered aconite root, datura seeds, or other substances, thought to be aphro- disiacs, are added. Before the introduction of Beam's test the only way of detecting hashish was by the very characteristic smell, the usual procedure being to extract the suspected substance with some solvent such as alcohol, ether or petroleum ether, to evaporate off the solvent, and to note the smell of the dried extract while warm. Such a test however is not very satisfactory even at its best, and- it fails entirely when the hashish is present in small amount, or if it is mixed with spices or other odoriferous ingredients, a not unusual con- dition. Beam's test as described by Dr. Beam himself is as follows : " The suspected material is extracted with petroleum ether of low boiling point and which leaves no perceptible residue when evaporated in the cold. The petroleum ether extract is separated, passed through a filter and evaporated to dryness in a small porcelain capsule. Both extraction and evaporation should be carried out in the cold. To the residue a few drops of weak alcoholic solution of potash or soda (about deci- normal strength) are added, and the liquid allowed to evaporate at room temperature. In the presence of hashish a rich purple or reddish purple colour gradually develops which on dilution with water takes a more bluish cast. It is very j)ermanent." ^ ' Wellcome Tropical Research Laboratories, Fourth Report. Khartoum, 1911. 144 LEGAL CHEMISTRY It has been found however that sometimes undoubtedly genuine specimens of Cannabis indica fail to respond to this test, and Beam therefore devised a modified test to which he states all hashish plants and preparations respond. This is as follows : " The petroleum ether extract is made as usual, and the evaporation of the solvent is carried out in a short test tube. To the residue is added a few cubic centimetres of a reagent j^repared by passing dry hydrogen chloride gas through absolute alcohol to saturation. In the presence of Cannabis extract the liquid strikes a bright cherry-red colour, which disappears on dilution with alcohol or water." ^ The author has frequently employed the original test, and has always found it most satisfactory, but has had very little experience of the modified test, and so cannot criticize it. Occasionally a genuine hashish plant is found which does not respond to either test. In such cases it is possible that the plant is young and that the resinous material is not developed. Hashish is principally used on account of its reputed virtues as an aphrodisiac. The growth of hashish in Egypt, its introduction into the country, as also the sale and holding of hashish, are all l^rohibited under heavy penalties. Practically all the hashish which finds its way into Egj'pt comes from Greece, where hemp is specially cultivated for the purpose. A number of cases have been submitted in which hashish has been found growing in Egypt. When the plants are received in good condition there is no difficulty whatever in their recognition. In addition to the eye and the micro- scopical examination, Beam's test should also be applied. It is sometimes useful to mount on cardboard, for exhibition in Court, a few of the leaves of the plants that form the subject of the action, and also leaves of other plants grown locally, which superficially resemble Cannabis indica, in order that the distinguishing features of each may readily be demonstrated, since the defence sometimes set up in such ' Wellcome Tropical Research Laboratories. Chemical Section. Bvilletin No. 3, April, 1915, HASHISH 145 cases is that the plant is not hashish but something that looks like it. BOOK OF REFERENCE. Some Notes on Hashish. A. Lucas, F.I.C. Caho Sci. J., Vol. V June, 1911. POISONS A KNOWLEDGE of the methods employed for the detection and estimation of poisons forms part of the training of every analytical chemist, and the syllabus of the examination for the Associateship of the Institute of Chemistry includes " toxicological analysis " as also " the toxicological effects of chemicals and drugs and a knowledge of the dangers from poisoning by chemicals used in trade j)rocesses," and " a general knowledge of the Acts relating to . . . the Sale of Poisofis." Toxicological analysis however in legal cases is work for an expert, and should never be undertaken except by those having special experience, since the life or liberty of others depends uj)on the results. The rough qualitative testing sometimes attempted in cases of suspected poisoning by medical men, having little or no experience of chemical analysis, is most unwise, as at the best it uses up valuable material, while at the worst it may lead to a mis- carriage of justice. Any qualitative testing for poisons should always be carried out with the same care and accuracy as in the case of quantitative work, and only by an experi- enced analyst. In this connection the trial of Mrs. Maybrick ^ should be read, as also Dr. Taylor's evidence in the Smethhurst case, 2 in both of which cases mistakes were made in testing for arsenic. In the former, a medical man with no experience of analysis attempted Reinsch's test, and naturally the results were neither satisfactory nor conclusive. In the latter, Dr. Taylor, when giving evidence in the preliminary examina- ' Notable English Trials: Mis. Maybrick. 2 Forensic Chemistry and Chemical Evidence. W. Jago. 11 146 LEGAL CHEMISTRY tion before the magistrate, stated that arsenic was present in the material tested, whereas in the final trial he stated that his assistant had made a mistake, and that the arsenic found had come from the copper used in the test. Attention may be drawn to the fact that the Royal Com- mission on Arsenical Poisoning in their Final Report (1903) made the following statements regarding the Reinsch and Marsh (Marsh-Berzelius) tests for arsenic. With regard to the former they state " . . .we are now satisfied that the use of the Reinsch test entails considerable risk of missing quantities of arsenic which, though small, are not to be regarded as negligible." With reference to the latter they state " The evidence shows that it is now recognized that a satisfactory estimation of the arsenic in a given substance can be made by comparing mirrors obtained by the Marsh- Berzelius method, after the substance examined has been subjected to appropriate treatment by which any arsenic present is obtained in a solution suitable for the proper application of the test." " We are satisfied that pareful analysts who estimate arsenic by this method can obtain results sufficiently exact and comparable for practical purposes, although the details of their procedures may differ." The Commission also state that by the Marsh-Berzelius method a series of mirrors differing by amounts of '002 milligram can be obtained which are sufficiently distinct and constant to be utilized for comparison, which means, as is pointed out, that if the test is applied to a solution containing' 10 grams of a given substance 0*2 part of arsenic per million in the substance taken can be estimated, or if applied to 50 c.c. of a given liquid 004 part of arsenic per million in the liquid can be estimated. " As regards the detection of arsenic by the Marsh- Berzelius method the evidence shows that when various substances are taken in quantities which have been found practically convenient, the presence of arsenic will be detected when in amounts well below -,-,,^0*^ grain per pound or (in the case of a liquid) well below :^y^,th grain per gallon." These figures represent 0"14 milligram per kilogram and 0*05 milligram per litre respectively. POISONS 147 Since the author's duties do not include toxicological analysis, no details or discussion of methods will be attempted. The following brief notes on poisoning in Egypt may be of interest. ' The substance most commonly employed in Egypt for the poisoning of both human beings and animals is arsenic, usually in the form of the yellow tri-sulphide (orpiment), but sometimes as oxide (white arsenic). The extensive use of sulphide of arsenic as poison is due to the fact that it can easily be obtained and can be bought clandestinely almost anywhere in the country despite the restrictions imposed on its sale by the Pharmacy Law, which results from its extensive employment for making the depilatory powder used by both men and women as one of the means of removing hair from certain parts of the body, a custom which Moham- medans consider essential to personal cleanliness. The powder consists of a mixture of sulphide of arsenic and slaked lime, which is made into a paste with water immediately before use and is applied in that condition. The chief active constituent of the paste is calcium sulphydrate which is formed by the interaction of the several constituents, though lime alone has depilatory action. It is a frequent mistake in connection with these powders to regard the arsenic as the valuable and essential ingredient, whereas it is the sulphur, and other sulphides, such as barium sulphide, are equally effective, and depilatory powders containing sulphide of barium in place of sulphide of arsenic are obtainable in Egypt. During the trial of Mrs. Maybrick, one of the witnesses (a hairdresser), who was evidently under the common and erroneous impression that it is the arsenic which is the active agent, stated that in the course of his business he made depilatory powders, using arsenic and lime, and that he generally employed yellow arsenic though some- times white arsenic. White arsenic however is quite useless for this purpose, and any depilatory effect produced by a mixture of white arsenic and lime is due entirely to the lime. It may be mentioned that the very poisonous nature of arsenic trisulphide is due to the fact that as a result of its 148 LEGAL CHEMISTRY method of manufacture from sulphur and arsenious oxide (white arsenic) it generally contains a large proportion of oxide. After arsenic compounds the next most common poison employed in Egypt for criminal purposes is mercury in the form of perchloride. The sale of poisonous mercury com- pounds, like the sale of arsenic compounds, is prohibited by the Pharmacy Law except to duly authorized persons under specified conditions, but as in the case of arsenic, the law is frequently evaded. The use of hyoscyamine as a poison is also of frequent occurrence, and this arises from the fact that both Hyoscyamus and Datura, each of which contains hyoscyamine, grow wild in Egypt. Of the latter there are several species, but only one variety of Hyoscyamus, namely H. muticus, is common. The seeds of H. niger however are also obtainable in Egypt, but these are imported from India. Many of the cases of poisoning by hyoscyamine originate in drugging for the purposes of robbery, which is carried out in Egypt much in the same manner as in India, the seeds of either Hyoscyamus or Datura, generally whole though sometimes crushed, being mixed with something which the victim is persuaded to eat and in which they are not very notice- able, such as rissoles or figs or the paste made from crushed dates, all of which form effective disguises for the poison. Until recently opium was also easily obtained in Egypt, the poppy being cultivated in Upper Egypt, where its growth was allowed although the sale of Egyptian opium in the country was forbidden. ^ The growth of the opium poppy however was prohibited in October, 1918. Cases of poisoning by aconite ^ also occur in Egypt. It is stated that this drug is sometimes added to j^reparations sold as aphrodisiacs. Such preparations generally consist • 1,.'J79 feddaus (I fcildaii = 1'038 acres) of poppy were grown in 1917. * In tlie Lain.son trial the terms aconite and aconitine were fre- quently employed as though they were synonymous, aconite however being the plant or plant root and aconitine the alkaloid obtained from it. POISONS 149 of hashish ^ with the addition of various spices, but when required for the use of excessive consumers to whom hashish alone is no longer sufficient, it is stated that opium, datura seeds, or powdered aconite root are sometimes added. Although aconite does not grow in Egypt the root appears to be readily obtainable. Poisoning by cyanide is also known, but since sodium cyanide is extensively employed for fumigating fruit trees its occasional misuse is not surprising. The most usual poison employed by suicides in Egypt, as in England, is carbolic acid. A chemist undertaking toxicological analysis, in justice to his work and to himself, must insist upon being supjDlied with the fullest information possible about all the cases in which he is consulted, and specially with information that may serve as a guide to the particular poison or class of poison to look for, otherwise he may waste both tim.e and valuable material in searching for something that from the symptoms and circumstances of the case is not likely to be present, and when he does obtain evidence of the nature of the poison, there may not be sufficient of the sample left for a quantitative determination or even for a conclusive test. BOOKS OF REFERENCE. Taylor's Pi-a,ctice and Principles of Medical Jurisprudence F. J. Smith. Vol. II. London, 1910. Poisons : Their Effects and Detection. A. Wynter Blyth. London, 1906. Royal Commission on Arsenical Poisoning. London, 1903. Lyon's Medical Jurisprudence for India. L. A. Waddell. Calcutta, 1914. Notable English Trials. Mrs. Maybrick. Edited by H. B. Irving. William Palmer. Edited by G. H. Knott. The Seddons. Edited by Filson Young. Dr. Lamson. Edited by H. L. Adam. Notable Scottish Trials. Dr. Pritchard. Edited by W Roughead. Madeleine Smith. Edited by A. Duncan Smith. I See page 142. 150 LEGAL CHEMISTRY POLLUTION OF WATER BY SEWAGE This is a common subject for litigation and one that cannot be decided without the assistance of the chemist. The most important aspect is that having reference to potable water sujDplies, but the pollution of canals, rivers and lakes, even though not used as sources of drinking water, is included, as also the pollution of estuaries and the sea. The pollution, too, may be either that occasioned by domestic sewage or may result from trade wastes. There are two sides to the question, one chemical and the other bacteriological, which vary in relative importance with the nature of the case : the former only will be considered. There is no single chemical test that can be relied upon to prove conclusively the presence of sewage contamination in a fresh water supply. Ammonia, nitrites, nitrates and chlorides, all of which may indicate sewage, may also all be derived at times from j)erfectly harmless sources. Thus, on one occasion, a sudden and considerable increase in the free ammonia content of the filtered water from some small sand filters examined regularly was found, and on investi- gation it was proved that the ammonia was derived from crude coal tar that had been employed to tar certain pontoons which had been launched and were then floating in the river over the water intake. In the same way high free and saline ammonia and nitrites are not uncommon in deep well waters, nitrates are no necessary proof of recent contamination, and chlorides may be a geological factor. When the question is one of the pollution of sea water by sewage, the amount of free and saline ammonia present provides a delicate and rehable indication of the presence and extent of the pollution. The proportion of free and saline ammonia in pure sea water collected off the coast of Great Britain is stated rarely, if ever, to exceed 002 parts per million and generally to be less than this amount, and any material increase is due to sewage contamination. ' ' The Chemical Evidence of Slight Sewage Pollution on Sea Water. Kenwood and Kay-Menzies. Seventh Int. Cong. App. Cliem., Section VlIlA, p. 259. POLLUTION OF WATER BY SEWAGE 151 In connection with this question of the pollution of water supplies by sewage, attention may be directed to the value of the determination of the amount of dissolved oxygen in the water as a means of gauging the extent of the pollution, since the oxygen content varies inversely as the impurity unless the contamination is too recent to have had time to produce its effect. The projDortion of dissolved oxygen normal to fresh water and to sea water respectively being known for given conditions of temperature and pressure, the extent to which oxygen is deficient becomes a measure of the degree to which it has been used up by the decomposing organic matter of the sewage, and hence is a measure of the pollution. A thorough investigation of the methods for determining dissolved oxygen were made both by Letts and Adeney for the Royal Commission on Sewage Disposal ^ and by Gill and Metzger for the Metropolitan Sewerage Commission of New York,2 and the results are to be found in the Reports of those Commissions. When the question is one having reference to the con- tamination of sea water, the extent to which land water, which includes sewage, is present may be ascertained, not only from the deficiency of oxygen, but also from the deficiency of chlorides, since sea water contains a consider- ably greater proportion of chlorides than land water, and the salinity of the water therefore is a measure of the extent to which the latter is present. In some cases, such as that of Alexandria, the land water may safely be assumed to be wholly sewage. The New York Sewerage Commission employed a special salinometer for the determination of chlorides, which gave good results even in the hands of men who were neither chemists nor experts in the use of delicate apparatus : the error of observation is stated to have been probably not more than one per cent., and the results accurate to within two per cent, after allowing for errors of observation. In connection with an investigation on the extent of the pollution of the Eastern harbour at Alex- andria, occasioned by the sewage from two small outfalls, I Fifth Report. App. VI. London, 1908. * 1910 and 1914. 152 LEGAL CHEMISTRY the amount of chlorides determined in the usual volumetric way proved very heljiful in suj^plemcnting the dissolved oxygen results. The determination of the nature and extent of any solid matter forming a deposit at the bottom of the water is also valuable and should never be omitted. Methods of examin- ation were worked out in England by tSorby for the Royal Commission on Metropolitan SeAvage Disposal in 1883 and by Stebbins for the New York Commission in 1910. Sometimes pollution by sewage has not actually com- menced but is merely threatened, and in such a case it is only a knowledge of the underlying principles of sewage purification and of what has occurred elsewhere that can help, and such knowledge is preferably that derived from personal experience, though much may be learned from the literature of the subject. Sewage purification is essentially a process of the deposition of solid matter from the liquid sewage, both the solid matter in suspension and that in emulsion and colloidal solution, with the subsequent breaking down of the matter so deposited, which is of complex constitution, into simpler and unobjectionable materials through the agenc}^ of bacteria and other forms of life. It follows therefore that mere dilution of scAvage by adding it to a large volume of water, whether fresh or salt water, is not f)urification, and that the deposition of the solid matter from the sewage will still con- tinue, although it may take years before the accumulation is sufficiently great to manifest itself as a nuisance. It follows too that if the sewage is passed into the sea, the well-known antiseptic action of the salt water, l\v diminishing tlie number of bacteria present, will considerably prolong the final decom- position of the deposited solid matter. ^ Sometimes fish, many kinds of which are foul feeders, will considerably diminish the amount of susjiended solids before they have time to settle to the bottom of the water, and in Alexandria harbour grey mullet are particularly noticeable performing this scavenging oi)eration round tlie ships. ' Tlie Decomposition of Sewage in the Presence of Sea A\'ater. Purvis, Mncalister and Minnett. Seventh Int. Cong. App. C'heni., Section VII1.\, p. 272. POLLUTION OF WATER BY SEWAGE 153 BOOKS OF REFERENCE. Royal Commission on Sewage Disposal : — Fourth Report. Vols. I and III. London, 1904. Fifth Report. App. VI. London, 1908. Seventh Report. Vols. I and II. London, 1911. Eighth Report. Vols. I and II London 1912 and 191.3. Reports of the Metropolitan Sewerage Commission of New York. 1910 and 1914. Studies of Fish Life and Water Pollution. Clark and Adams. Eighth Int. Cong. App. Chem., Vol. XXVI, p. 199. The Diffusion of Sewage in Water. Kenneth Allen. The Siu'veyor, Vol. LI, No. 1309, and Vol. LIII, No. 1367. ROBBERY FROM LETTERS AND PARCELS It is a comparatively easy matter to open a letter or parcel fastened in the usual way or even sealed with wax and to re-fasten or re-seal it in such a manner that it will pass muster without giving rise to suspicion unless critically examined, but it is very difficult to do so without leaving some traces of the operation, and these traces may be found by any one having experience, if careful search is made. As a rule the better the quality of the sealing wax and the worse the quality of the envelope or paper the more evident are the traces left. A cloth-lined envelope and a number of seal impressions made with wax of an unusual colour, such as green, blue or yellow, affords a considerable measure of protection. A special mineral ingredient, which can readily be tested for, if added to the wax, simplifies the detection of false seals. It would manifestly be impolitic to describe the various ways in which letters and parcels may be tampered with, though the expert to whom such questions are referred naturally acquires considerable experience in these matters. Before the expert receives a letter or parcel for investi- gation it will almost necessarily have already been opened by the receiver, and it will generally be found that no examination whatever was made of it at the time of receipt, that no notice was taken of its condition, that little or no 154 LEGAL CHEMLSTRY care has been taken to j^reserve it in the exact state in which it was received, and frequently valuable evidence has been destroyed by the careless way in which it has been handled, with the result that the expert is handicapped from the very commencement of the enquiry. The examination of letters and parcels from which some- thing is alleged to have been abstracted during transit consists very largely of a careful scrutiny (both with the naked eye and also with a lens) of the envelope or wrapper, and also of the wax seal impressions and string, if any, together with a chemical analysis of the gum on the envelope and the wax of the seal impressions. If an envelope of which the paper has a glazed surface has been steamed or otherwise wetted in order to open it, evidence of this will generally be found in the different and duller appearance of the paper in those places where the water has touched it, the smoothness and brilliance of the original surface being destroyed : if the paper is not glazed the envelope may be opened without any evidence of the operation being left unless the paper is of very poor quality, in which case even though unglazed it will show signs of having been wetted. When gum is applied to an enveloiJe in order to re-fasten it after it has been opened an excess is sometimes used which squeezes out from under the flap and can readily be seen. Such an appearance however, although always suspicious, does not necessarily indicate that the envelope has been opened and re-fastened, since slight smears of gum are often found on envelopes that have not been tampered with, these being due to the fact that with a well-gummed envelope, freely moistened, a little of the original gum may be squeezed out and smeared on the envelope just beyond the edge of the flap. If the envelope has been opened by cutting one of the edges and has afterwards been closed again, this oper- ation may have been so skilfully performed tliat no evidence whatever will be found on a careful examination of the outside of the edge even ^vith a lens. To detect such a mode of opening and re-closing it is necessary to slit open all tlie four sides of the envelope with a sharp knife and to examine ROBBERY FROM LETTERS 155 the edges inside. In every case where tampering is sus- pected the envelope should be opened in such a way as to allow the inside, and particularly the inside of the flap, to be carefully examined. It should be remembered, however, that it is not always the top flap of an envelope which is tampered with, but sometimes the bottom flap or one of the flaps at the sides. Numbers and marks placed on envelopes by the post office employees are sometimes written with indelible pencil, and such marks may show signs of having been wetted if the envelope has been tampered with, and the name and address of the sender or other indications on the envelope, if made by means of a rubber stamp and aniline ink, as is often the case, may show the same thing. False wax seal impressions may frequently be detected on account of the seal used not being an exact reproduction of the original, or because the colour or the composition of the wax are not an exact match. It is possible however to reproduce a seal impression in such a manner that the im- pression itself defies detection, but even in such a case evidence that the envelope has been tampered with is frequently left either during the removal of the original wax or during re-sealing. It will be found a great help in the detection of forged seal impressions and the opening of envelopes and parcels if the expert acquires personal experience of how to do these things. A few references to methods may be found in several books, such as that on Criminal Investigation by Hans Gross, but these should be accepted only as preliminary suggestions, since far more satisfactory methods exist though they cannot be described. A considerable amount of valuable information may be obtained from a careful examination of the sealing wax on an envelope or parcel which has been sealed. Thus finger prints, or marks made by a fabric, or even threads from a fabric may be found on the wax : sometimes, too, it is possible to prove that a seal impression consists of two separate and distinct layers of wax, one superimposed on the other : the nature and percentage of the ash may also furnish valuable information which may allow of one wax 156 LEGAL CHEMISTRY being distinguished from another of the same appearance : even small differences in colour are important, since they may indicate not only different kinds of wax, but may also show the manner in which the wax has been melted. Thus, for instance, sealing wax may be melted in the flame of a lamp or candle, or in larger quantity, in a pot by means of a burner. When melted in a flame the wax generally takes fire unless only a very small impression is made, and when this happens, that portion which has been alight is partly burned, and j^articles of black carbonized material can be seen in the wax, the colour of which is generally darkened. The amount of burning and hence of carbonization, however, may be so slight that it is not noticeable, esjDccially in small seal impressions. Frequently in post offices and banks where sealing w^ax is required in large amount, it is melted in a small j)ot over a burner, which may be a spirit lamp, a gas flame, or an electric heater. When heated in this manner the wax does not inflame, and hence does not carbonize, although some colour change may and frecjuently does take place. The colour of a wax seal impression depends there- fore not only upon the colour and composition of the original wax, but also on the way it has been melted. When melted in a flame the wax generally becomes darker in colour owing to carbonization, and in addition ])articles of carbonized material are generally visible : when melted over a burner there is generally no darkening, though sometimes a change of colour, and there are no particles of carbonized matter. The amount of visible blackening, however, also depends upon whether or not the molten wax on the paper has been stirred with the stick of l)urning wax as is sometimes done, since in this case the black particles may become partly or wholly masked by fresh wax and so may not be apparent. The spots and streaks of different colour sometimes seen in a wax seal impression are generally caused by the existence of particles of differently coloured wax in the original stick due to imperfect mixing. The following cases will illustrate some of the points to which attention may profitably be directed. 1. This case was concerned with the robbery of a large sum in bank notes from a scaled envelope, which had been ROBBERY FROM LETTERS 157 sent through the post. Part only of tlie notes had been taken. The following clues were found : — The wax seal impressions were all identical and had all been made with the same seal, and this seal was the genuine seal of the firm forwarding the letter or was identical Avith it. There were two different and distinct layers of wax on two of the impressions, one layer being subsequent in point of time to the other, and superimposed upon it. There were wavy lines, and a few very small black- looking fibres on one of the wax impressions. The fibres were found on microscopic examination to be wool of a very dark blue colour, and the lines to be the impression of a woven fabric. In two places adhering to the under side of the flap of the envelope there were fragments of j)aper torn from the surface of the envelope beneath the flap, and these were embedded between two layers of wax, and on the envelope below the flap there were places from which the surface layer of the paper were missing, and there was wax on these torn surfaces. This could not possibly have happened unless the envelope had been sealed with wax beneath the flap (the usual method adopted by the firm forwarding the letter), then opened, the surface of the paper being torn during the process, then re-sealed with more wax. All the wax was identical in colour and chemical compo- sition, and corresponded to that used by the firm sending the letter. The wax used by the addressee, although of the same colour as the wax on the envelope, was of very different chemical composition. The post office official wax w^as also very different in chemical composition from that on the envelope. The dark blue woollen fibres found on the wax of one of the seal impressions corresponded to the material of the coat of one of the employees of the firm sending the letter, and the right hand sleeve of the coat was turned up and frayed at the turned-up edge. There was evidence however that this employee might have been called in to assist in the first sealing of the envelope. It was evident from the above facts that after the 1.58 LEGAL CHEMISTRY envelope liad })een sealed in the first place, it was opened at the flap and then re-sealed in the same manner as before, the additional wax being identical in both colour and com- position to that originally employed, and the impressions on the wax being probably made with the firm's own seal. Everything therefore pointed to the robbery having taken place before the envelope left the premises to be taken to the post, and that it was done hurriedly, since all the notes were not taken. Against this, however, w^as the fact that the postage stamps on the envelope represented the correct postage and registration fee for a package of the weight which the envelope originally had when it contained the full complement of notes, whereas when the letter reached its destination its weight was some sixty grams less, and hence it was then considerably overstamped.i To meet this difficulty, however, it might be assumed that the messenger who took the letter to the post, either mechanically or inten- tionally, asked for stamps to represent the original weight. It was admitted that letters of the same kind and weight had been sent to the same address on several previous occasions. 2. This case, like the last, was one of the robbery of bank notes from a sealed envelope which was sent through the post, the sum stolen being £5,000. The clues found were very similar in some respects to those in the jirevious case, and it was possible to prove that in several instances the wax seal impressions were formed of two different layers of wax, one superimposed on the other. Both lots of wax were identical, and the seal used to make the impressions was the genuine one or an exact reproduction of it. In this case all the bank notes had been taken out and rejilaced by a packet of the same weight consisting of pieces of Arabic newspaper. The robbery had probably been carried out by some one having access to the firm's wax and seal, and also to a balance for adjusting the w^eight of the newspaper packet. This had occupied some time, or careful preparation had been made beforehand for it. ' Apparent differences in weight may be due to incorrect scales and weights, or to careless weighing : actual differences in weight occur from pieces of sealing wax being inadvertently detached or from the presence of dirt or moisture. ROBBERY FROM LETTERS 159 3. This again was a robbery of bank notes from a sealed envelope sent through the post, the amount stolen being £3,000. In this case, as in the one last mentioned, all the notes were abstracted and pieces of newspaper sub- stituted. The following significant facts were noted : — Of the nine wax seal impressions on the envelope five were on the flap and four elsewhere. The wax of the latter was identical both in colour and in composition with the firm's wax, and the seal used was identical with the firm's seal, and these four impressions were undoubtedly part of the original sealing. The colour of the wax of the five impressions on the flap was slightly but definitely different and darker than that of the other impressions though the composition was the same : small differences in detail proved that the seal used for these impressions was different from that used for the other four impressions, and that it was not the firm's seal. The post office sealing wax was different both in colour and in composition from any on the envelope. A portion of the surface layer of the i^aper of the envelope beneath the flap was torn away and was adhering to the flap, and in several places small pieces of paper were found between two layers of wax, all of which proved that the envelope had been opened and resealed after it was origin- ally fastened. The newspapers, with one exception, were all published in Alexandria, the place from which the envelo|)e was sent : the exception was a Cairo paper having an extensive circu- lation in Alexandria. One of the Alexandria papers was dated the same day that the envelope was posted. The conclusions arrived at were that the robbery cer- tainly took place in Alexandria, and not at the post office, and unless the firm had other wax different from that of the four seal impressions and from that of a specimen submitted for examination, which point was not satisfactorily cleared up, then the robbery probably did not take place on the firm's premises, since in such a case it would have been a very easy matter to have obtained some of the firm's wax ; hence by exclusion the robbery occurred while the envelope was in transit between the firm's premises and the post office. 160 LEGAL CHEMISTRY 4. This also was a case of the robbery of bank notes. Two siniihir envelojjcs were sent by post by the same person from the same phice on the same day to the same address. Each was stated to contain bank notes, one for £400 and tlie other for £320. On arrival the £320 was intact, while the other enveloj)e contained pieces of thick j^ink paper instead of bank notes. This paper consisted of wrappers from packets of a well-known local cigarette tobacco. Both envelopes were sealed in the same way with five wax seal impressions, all of which were identical and had been made with the same seal. There were no signs whatever that the envelope from which the bank notes were missing had been opened and re-sealed, nor that it had been tampered with in any way. The envelopes were of the kind sold onl}'^ at the Post Office, and it was proved that they had been purchased several days before the robbery : the writing was that of the local post- master, who admitted that in contravention of regulations he had addressed and sealed the letters, using the post office wax and the seal of the sender ; he stated however that the envelopes were already gummed down when they were handed to him. As a result of the enquiry it was proved that the owner of the money had robbed himself and had arranged matters in such a manner as to throw suspicion on the postmaster. 5. In another case there were no signs that an envelope, from which it was stated a remittance had been stolen in transit, had been tampered with. The paj^er showed no evidence of having been wetted ; there was no evidence of extra gam ; six seal impressions across the flap made with blue aniline ink showed no signs of having been wetted, and the two parts of these seal impressions (the one on the flap and the other on the envelope) corresponded exactly ; two pieces of stamp edging placed across the flap also showed no evidence of having been removed and replaced^ and there was no evidence of the envelope having been opened in any other wa3^ It seemed ])robable that the money had never been placed in the envelope. BOOK OF REFERENCE. Criminal luvostigatiou. Ha)is Gross. Trans. Madras, 190G. STAINS AND MARKS 161 STAINS AND MARKS Chemistry is the science of small things, and the chemist habitually tests for ingredients which are only present to the extent of a few parts per million or even per hundred millions, and the tenth, the hundredth and even the thousandth part of a milligram of a substance can sometimes be deter- mined. The chemist, therefore, is peculiarly fitted to search for and to examine stains and marks. This, however, is rarel}^ recognized, with the result that much valuable evidence is frequently lost. The significance of blood stains in cases of crime, such as wounding or murder, is manifest, as is also the evidential value of finger prints and foot marks. These however have already been dealt with, and the stains and marks which will now be considered are such as the following cases will illustrate. 1. In connection with a murder, the question of whether some pieces of white cotton cloth found in the house of a suspected person were identical with a piece of similar-looking material, which was wrapped round the body of the victim, was of considerable importance. This case will be described when dealing with the subject of Textile Fabrics, but among the minor points investigated were some pink- coloured stains on all the pieces of cloth. The stains on the several pieces were alike, and the pieces of cloth were identical, and at one time had manifestly been sewn together and had probably formed the loose washable cover for a couch, and in all probability there had been a pink-coloured material underneath from which the stains had been derived. 2. A waistcoat was submitted for examination to ascertain whether it would yield any clues to the history of the wearer. This case has been described elsewhere, but one point may be mentioned in this connection. The lining of the waistcoat was of the usual white cotton material made in several pieces and then sewn together. One piece bore a stain which seemed to have been made by perspiration, and this stain, which was semi-circular in shape, stopped abruptly at a seam where two separate pieces of the lining 12 162 LEGAL CHEMISTRY were joined, and was not present on the other side of the seam, but was continued on the turned-down edge where the first piece of material was folded in order to sew it to the second. Evidently, therefore, the stain had not been acquired while the lining was in its then position, and it seemed likely that the stained piece had previously formed part of another waistcoat. If so, then the waistcoat, although new, was probably part of a ready-made suit for which an old piece of lining had been used. 3. In this case a man had been killed by having his throat cut, and near the body a small piece of fabric was found on which, in addition to blood stains, were black smears, marks of yellow material, much blackened, and patches of white metal in very thin layers. Analysis proved the black material to be carbon, the yellow to be resin blackened by carbon, and the metal to be plumber's solder. The fabric had there- fore been used by a plumber for " wiping " a joint, and thus a valuable clue was afforded for the police to follow up. In connection with the subject of Fires a case is quoted in which some whitish material caked on the outside of a sack proved to be wheat flour, and this enabled the sack to be traced to a baker. When dealing with the subject of Counterfeit Coins two cases are mentioned in which impressions of parts of the designs of coins were found on pieces of wood. These proved to be valuable links in the chain of evidence. In other cases impressions of coins on metal (lead, copper and iron) have been found, and in some instances it was possible to state that the coins with which the impressions had been made were counterfeit. In another case a large number of circular impressions the size of one of the Egyptian silver coins were found on two blocks of wood which had been used as a support for a press, and on several of these impressions there were parts of the design of a coin. Although the presence of the press, which was without dies, was suspicious in itself, it was not sufficient to connect the man on whose premises it was found with counterfeit coining, since it was possible that such a press might have been used for legitimate pur- poses, but the impressions of the coins on the wooden base placed it beyond doubt that it had been employed for making STAINS AND MARKS 163 counterfeit coins. In another instance, from the marks left on a wooden instrument which had been employed for putting the milling on counterfeit coins it was possible to prove, not only that the instrument had been used considerably, but also the size of coins which had been milled. In various other cases of counterfeit coining, small amounts of moulding composition (sand, clay, plaster of Paris) found in brass and iron casting frames proved that these had been used, and in a few instances where the moulding composition was intact and bore impressions of coins, it was possible to state that certain coins found on the premises had been made in those particular moulds. In some cases from the presence or absence of rust it has been possible to say whether certain machines and dies used for making counterfeit coins had been recently employed or not, and in one case, from some splashes of colour wash on the iron base of a press it was possible to place a limit to the time since which this had last been used. The chemical examination of shot marks in clothing may conceivably occasionally prove of value ; thus, if the cloth immediately surrounding a shot-hole gives a positive reaction when tested for alkali and potassium this may indicate the use of black powder fired at short range. The presence of grease on the clothing may also indicate black powder, since lead bullets with which black powder is used are some- times greased, while bullets which are used with smokeless powders are not usually greased. ^ The grease is tested for by placing the garment between tissue paper and ironing with a hot iron. Such indications, however, should be apj)lied with the greatest caution since grease may be, and sometimes is, used with steel coated or other bullets employed with smokeless powder, the Austrian military bullet for example being a steel-coated bullet which is greased to prevent it rusting. A waxed wad, or wax such as is sometimes used round the base of a bullet in a smokeless powder cartridge might also leave a stain on the clothing, and wax gives a similar mark to grease on paper when pressed with a hot iron. As already mentioned when dealing with the subject of ' Th. Lochte, Chem. Ztg., 35, 1107, through Chem. Abstracts, 1912, 3184. 164 LEGAL CHEMLSTRY bullets it is stated that on a lead bullet which has been fired through clothing it is sometimes possible to find an imprint of the texture of the cloth first penetrated. Stains and marks on documents are sometimes of con- siderable value as evidence. A few illustrations may be given. It frequently happens that the post office cancellation and date marks on envelopes are impressed so vigorously that the outlines of these marks are indented on the letters inside. In several cases it has been possible to prove that the contents of certain envelopes received through the post had been through the post on a previous occasion, since they bore marks made by a joost office stamp which did not corre- spond to any on the existing envelope. In one instance the marks were on an inner sheet only and hence the paper had been folded differently on the previous occasion. Also, if a particular post office mark shows through on to the far side of the envelope to that on which it was impressed, any letter inside must also have been marked, and hence in such a case a letter, folded sufficiently large to fill or almost fill the envelope, and which does not show the mark in question cannot possibly have been in the envelojDe at the time it was stamped. In one case the fact that a certain grease stain which occurred on both the back and front of an envelope did not exist on a letter which was alleged to have been in the envelope, strengthened other evidence that the letter was a forgery. Sometimes stains of ink or colour on a docu- ment enable a connection to be established between one document and another or between a document and a particular person. The testing of stains and marks does not as a rule obliterate or destroy them, but if this seems likely to happen they should first be photographed, so that a permanent record may be preserved for future reference or for production in Court. Claims made against insurance companies and others for alleged damage to goods by water can frequently be decided on chemical evidence, more particularly if the claim is one for damage by sea water. One of the important factors in such cases is sometimes the presence and nature of stains and marks on the goods, and in other cases the entire absence of staining. STAINS AND MARKS 165 BOOKS OF REFERENCE. Criminal Investigation. Hans Gross. Trans. Madras, 1906. La Photographie Judiciaire. R. A. Reiss. Paris, 1903. La Police et I'Enquete- Jvidiciaire. A. Nicefero. Paris, 1907. Manuel de Police Scientifique. Vol.1. R. A. Reiss. Lausanne, 1911 STRING AND ROPE The examination of string or rope found in connection with a crime will often furnish valuable clues. Not only should the nature of the fibre be determined, but attention should also be directed to the ends to ascer- tain whether they have been cut or frayed, and also to any knots or loops, and to the manner in which these have been tied. The fibres used for making string and rope ^ are very numerous, though the principal are hemp, jute and coir (Cocos nucifera), the first however not being confined to hemp proper {Cannabis saliva),- but including such fibres as Sisal hemp {Agave rigida), Manila hemp {Miisa textilis), kSunn hemp {Crotalaria juncea), New Zealand flax or hemjD {Phormium tenax), and many others generally termed hemp. In Egypt ropes are extensively made from date palm fibre and string from Deccan hemp {Hibiscus cannabinus).^ Cotton is also used for rope-making. When examining a rope it is useful to determine not only the nature of the material, but also the " lay " which is the system on which the strands forming the rope are twisted, and which is measured by the angle between the direction of each strand and the direction of the centre line of the rope, the size, which is the circumference in inches, the number of strands, the number of yarns per strand and the number of fibres per yarn. The nature of the fibre may' be ascer- ' By rope is meant cordage only, iron and steel wire rope being excluded. - Of hemp proper there are several varieties which differ in appear- ance and quality, the two principal met with in Eiu'ope being Italian hemp and Russian hemp. 3 Also known as Ambari hemp and called Teel in Egypt. 166 LEGAL CHEMISTRY tained in the manner mentioned in connection with the subject of Textile Fabrics. A few cases in which the examination of rope has provided useful information may be quoted. 1. In the second murder case described under Textile Fabrics, the rope with which the body was tied was of two kinds, one being native rope made from date palm fibre, and the other a better quality machine-made rope not of Egyptian manufacture. One of the pieces of rope was tied in a manner similar to that used in Egypt for hobbling animals. 2. In another case a piece of thick rope which had been emploj^ed in connection with scaffolding, and which had given way, and so caused an accident, was submitted to ascertain whether it had broken naturally or whether it had been cut intentionally. On examination it was found that the rope was strong and of good quality, and although it showed signs of Avear along its whole length, yet apart from the broken portion, it was still fit for use. It had not been cut with a sharp instrument, but manifestly had worn through, probably bj^ friction against a rough surface. From the appearance of the broken ends, the rupture had been gradual, and if the rope had been inspected the weakness could hardly have escaped detection and so the accident might have been prevented. TEXTILE FABRICS The examination of textile fabrics, so far as such work concerns the chemico-legal expert, is generally limited to the deter- mination of the nature of the material, and the question of its identity or non-identity with some other material of similar appearance. Sometimes however the strength of the material or the nature and permanence of the dye are required. The identification of the fibres composing a fabric is partly microscopical and partly chemical, thus animal fibres may be distinguished from vegetable fibres by their micro- TEXTILE FABRICS 167 scopic appearance, by their behaviour on burning, by the colours produced by certain reagents and in some cases by the different effect of certain dyes, or by a difference of solubility in different reagents. Vegetable fibres may be distinguished from one another by their microscopic appear- ance, by the affinity of one kind of fibre for a particular dye which does not affect others, and by the difference of solubility of the various fibres in different reagents. But not only may different fibres be distinguished from one another quali- tatively, but the proportion in which the several kinds of fibre are present in a mixture can be determined. Thus cotton and wool in a mixed fabric can be separated and weighed, and cotton, wool and silk occurring together can also be separately determined. This is done by taking advantage of the fact that wool is soluble in hot caustic soda or potash, cotton in strong cold sulphuric acid and silk in a concentrated boiling solution of zinc chloride. Another way in which the relative proportions of the various fibres in a mixture may be determined is to so treat the fabric that each kind of fibre becomes dyed a different colour, and then to ascertain the proportion in which the colours occur. The following cases, having reference to the examination of textile fabrics, may be quoted. 1. This case concerned the question of whether a piece of material found wrapped round the body of a murdered woman was identical with several other pieces of similar- looking material found in the house of one of the suspected persons. On examination it was found that the various pieces of cloth were cotton, that all the pieces were of the same fineness, that is to say the number of threads to the inch was the same in each case, and that all were of the same width between the selvedge edges. These facts, together with the further facts that all the pieces bore a similar coloured stain, and all had been sewn with similar and somewhat unusual thread, small portions of which still remained, and that all fitted together, justified the report that the several pieces were of identical material, and that at one time they had been sewn together. 2. In this case the naked body of a man was discovered in a canal tied up in a sack, which was weighted with stones. 168 LEGAL CHEMISTRY The sack and stones were submitted to ascertain whether any clues to the murderer could be found. The sack was of a kind and quality largely used in Egypt for cotton seed and cereals, and similar sacks may be obtained almost anywhere in the country. The sack, however, had been patched in two places, and in both instances in a similar manner and with similar material, and on a microscopical examination, this material was found to be camel hair, and the thread with ^hich it was sewn was also of camel hair. Similar thread had also been used to mend one corner of the sack. From these facts the following conclusions were drawn : — That the sack had at one time belonged to some one who could not readily obtain a new sack and to whom therefore a sack was a thing of value and something to be repaired. That since similar sacks are extensively employed in Egypt, the ordinary Egyptian would not experience much difficulty in obtaining sacks in good condition, and hence would have no need to mend an old sack. Moreover, it is specially characteristic of the ordinary Egyptian that as a rule he does not mend things, but uses them until they cannot be used any longer, and then discards them. Hence, the fact of a mended sack seemed to point away from an ordinary Egyptian, and at the same time to some- one poorer and less able to obtain sacks, that is by exclusion, to a bedouin. A bedouin was indicated too by the nature of the stones used to weight the sack which, with two exceptions, were rounded flints, the exceptions being silicified wood, all of whicli must have come from the desert.' It was advised that search should be made for a bedouin, and it was subse- quently ascertained that the crime had been committed by a bedouin. 3. In several cases in which cloth suspected to have been stolen has been forwarded for identification, it has been found impossible, in the absence of any special distinguishing ' It was of course by no means certain that these stones had been taken directly from the desert, similar stones being sometimes used in Egypt for railway ballast. TEXTILE FABRICS 169 mark, to prove the theft. Although the cloth has been of similar material (linen in some cases, cotton in others, and linen warp and cotton weft in others) and of similar count to the samples from stock submitted for comparison, it has been of a kind that is very common, and hence no definite proof that it was stolen was possible. BOOKS OF REFERENCE. Fibres used in Textile and Allied Industries. Mitchell tie Prideaux. London, 1910. The Textile Fibres. J. Merritt Matthews. New York, 1913. Sttidio Microscopico E Cheniico Pel Reconoscimento delle Fibre Vegetali, Lane, Peli, Pelliccie. A. Solaro. Milan, 1914. Technical Testing of Yarns and Textile Fabrics. Herzfeld. London, 1902. TOBACCO The cultivation of tobacco in Egypt is prohibited, and since attempts are sometimes made to grow it, the chemico-legal expert has such cases referred to him for identification. This involves no difficulty if the plants are received in good con- dition. The examination is largely microscopical, the hairs of tobacco being very characteristic, and the appearance of the starch and of cross sections through the midrib being also helpful. The expert may sometimes be called upon to identify a specimen of cut tobacco, or to say whether two different specimens are identical or not. Thus, in the case of the attempt on the life of H.H. the late Sultan Hussein of Egypt in 1915, several cigarette ends, one being still alight, were found on the floor of the room from which the bomb was thrown, and it seemed possible that this latter had been used to light the fuse of the bomb. These cigarette ends bore the name of a certain tobacconist, and cigarettes bearing the same name and mark were found in the house of one of the accused. The tobacconist stated that he supplied the accused with a special mixture, and hence it became important to ascertain whether the tobacco in the cigarette ends and that 170 LEGAL CIIEAriSTRY it) the cigarettes of the accused person was identical, and whether it was the particular mixture in question. The chief differences het-vrron varioinr-teliSLCCos are the size, sTiape^^jioloia' and general appearance o f tlw^sjf af, and lom-^ai-ticularly the flavour on smoking. The dii chemical composition of different tobaccos are not rule sufficiently marked to be helpful, and it is most unlil 'that the analysis of a single small sample (and no more^than ^his is generally available) would be of any use fojxidenti- ipn purposes. When_a_tQhaccQ is cut-y— thtrTsIzer^sirape and generai-appiarancfi-jof the- leaf areriOsET and in the case of a cigarette that has been partly smoked, the colour of the tobacco may be modified by the moisture and products of combustion which accumulate in the unsmoked end, and the best test, namely the flavour, cannot as a rule be applied at all, since even if the amount of tobacco available were sufficient, such a test would entirel}' destroy the evidence. Hence, one is forced back upon such facts as the general appearance of the tobacco, both to the naked eye and also when examined under a lens or with a microscope. In the case already referred to the tobacco was very finely cut, and this fact together with the proportion and size of the cross sections of stem present made it very characteristic and quite different from a number of other cigarette tobaccos examined, and since the tobacco of the cigarette ends and that of the cigarettes belonging to the accused had the same characteristics as well as the same general appearance and colour, it was probable that they were the same tobacco. In England the adulteration of tobacco with foreign leaves is practically unknown, the chief adulterants being genuine tobacco of inferior kinds and water in excess of the legal limits : excess water however cannot be employed in the case of tobacco which is stocked for any length of time, or for that put up in tins, since such tobacco would become mouldy. In Egypt it is sometimes stated that banana leaves, colocass leaves {Colocasia antiquorum) and the thin hair- like fibres from maize cobs are employed locally as adulterants of tobacco. During normal times, however, it is very doubt- ful whether tobacco is adulterated at all except with other tobacco of inferior kinds, and no instance of adulteration TOBACCO 171 has come under the author's notice, but during the war of 1914-18 when tobacco was scarce and therefore expensive, adulteration was certainly practised, and banana leaf and other plant leaves not identified were found : in one case some cigarettes examined contained no tobacco whatever, and in another instance some cut tobacco was wholly fictitious. As an example of the manner in which tobacco may be sophisticated it may be mentioned that liquid tobacco " flavours " are openly sold for imparting special aroma to tobacco, some examined being described as Plug, Latakia, Gold Flake, Cavendish and Virginia respectively. These flavours are not obtained from tobacco, but are purely synthetic products, and manifestly they can only be employed for purposes of deception in the same manner that artificial essences are used for flavouring j^lain spirit in order to simulate brandy, whisky, rum, etc. It may be mentioned that Egyptian cigarettes are not made from Egyptian grown tobacco since there is no such thing, the cultivation of tobacco in Egypt as already stated being prohibited, but Egyptian cigarettes are cigarettes made in Egypt from imported tobacco, which comes chiefly from Turkey in Europe, Asia Minor, Greece and Russia. In addition to the ordinary Nicotiana Tabacum, another variety of tobacco, namely Nicotiana rustica or Tombac is imported into Egypt, chiefly from Persia and Turkey, and is used for smoking in the water-pipe. TRAPS FOR CRIMINALS In addition to the innumerable traces that a criminal leaves when he commits a crime, all of which are in the nature of traps that may ultimately ensnare him, there are other and deliberate traps which the honest man uses in self -protection. Some of these, such for instance as burglar alarms, not only provide a means of detecting and possibly capturing the criminal, but act also as preventives of crime. It is only proposed to describe those traps that concern the expert and which may be divulged without impropriety. 172 LEGAL CHEMLSTRY Bank notes. It is a very general practice for secret marks to be placed on bank notes. These usually consist of a slight intentional defect in the engraving, or of a slight alteration in the form of a particular letter or figure or other part of the design, or in the addition of some small special mark. Such indi- cations are helpful in enabling a genuine note to be easily and quickly recognized, and their absence is a certain proof that a note is counterfeit, no matter how good an imitation it may be. Secret marks ho\\'ever are necessarily repro- duced by all photographic jjrocesses, and hence their value is limited and their presence is not a proof that a note is genuine. Such marks probably never act as a deterrent against forgery. In addition to the secret marks put on bank notes at the time they are made, it is the practice of the police in the course of certain investigations to mark bank notes in such a way that they may be identified and distinguished from other similar notes. This is done as a rule with invisible ink, which is afterwards developed. Bank notes, except those of the Bank of England, are protected to some slight extent against the photograjDhic reproduction of the design by the use of specially selected colouring. When an ordinary photographic plate is used, red, orange and yellow colours appear practically black, green is dark, while blue and violet are light, blue photographing almost like white. These difficulties however may be over- come by the use of orthochromatic plates and liglit filters. The colouring too is difficult to match exactly, and hence it serves the same purpose as the elaborate watermark and special paper of the Bank of England notes, though in a less degree. Cheques. Cheques may be protected against alterations by the use of special security paper, the paper being treated with certain chemical ingredients which become discoloured by any reagent employed to remove the writing. In some cases cheques are printed on paper having a coloured surface TRAPS FOR CRIMINALS 173 on the side used, the colour being sensitive and readily showing any attempts at the removal of the original writing. A more usual safeguard against the alteration of cheques however is the use of coloured safety ink for printing the groundwork of that portion on which the amount and signature are wTitten, and as this ink is sensitive to the action of chemical reagents, and generally also to the action of water, any attempt to efface the writing is at once betrayed. Coins. Secret marks are sometimes placed on coins by the mint, and unless a coin is worn their absence is a certain proof that the coin is counterfeit. Too much reliance however should not be placed upon the presence of secret marks since they may be reproduced by the counterfeiter. Such marks never act as deterrents against forgery. The police sometimes mark coins in order to identify them again, and this is done by scratching some minute letter or sign on them. Envelopes. In order to prevent envelopes being opened by wetting or steaming it has been suggested that the flap should be coated with isinglass or glue in place of gum, and that the part of the envelope beneath the flap should be treated with chromic acid, and it is stated that the isinglass or glue becomes so hard as to be absolutely insoluble in water, and hence the envelope cannot be opened except by cutting or tearing. It has also been suggested that the flap should be impregnated Avith one chemical ingredient and the part of the envelope immediately beneath it with another, so that when water or steam is applied to open the envelope the chemicals will re-act with one another and discolour the paper. The same action however would take place if the envelope were wetted accidentally, or if it were wetted too much when being closed in the first instance. Finger Prints. Sometimes it is desired to obtain the finger prints of those 174 LEGAL CHEMISTRY who touch certain objects. This is readily done by coating the object in question with a thin film of something that will take and retain the impression of the fingers. For glass a thin layer of gelatine and glycerine, the latter being added to prevent the gelatine drying, will be found satisfactory, while for many opaque objects a thin coating of oil or grease is effective. If the suspected person can be detained and examined it is sometimes helj^ful to coat the article likely to be touched with something that will stain the hands, such as aniline colour or a solution of silver nitrate. This latter may be prevented from drying by adding a deliquescent material Hke calcium nitrate. Ink. A special ingredient is sometimes put into ink in order that forgery may readily be detected and demonstrated. Ink of this kind has been recommended for entries made with a rubber stamp and aniline ink on certain certificates, the occasional forgery of which was anticijDated, and also for stamping meat in the Egyptian Government abattoirs, and for the latter purpose particularly has proved very successful. Margarine. In order to facilitate the detection of margarine if fraudulently added to butter, the margarine is frequently " ear-marked." This is done in Belgium, Austria and Germany by the compulsory addition at the time of manufacture of ten per cent, of sesame oil, and in Denmark by the addition of five per cent, of sesame oil and one per cent, of ])otato starch. Both sesame oil and potato starch can readily be detected by chemical tests. Pickpockets. In order to convict a pickpocket the police sometimes put a little dry aniline colour in the pocket of a decoy. The dye stains the hands of the thief and, even if noticed, it is difficult to remove and traces are liable to be left. TRAPS FOR CRIMINALS 175 Postal Ordeirs. These are jDrotected in various ways, one of which is by the use of water-marked paper. Postage Stamps. The colours with which postage stamps are jjrinted are frequently intentionally sensitive and fugitive and readily show any attempt at removal of the cancellation marks or others alteration. Stamps for fiscal purposes are sometimes printed with doubly sensitive ink. Sometimes too safety pa|)er has been used, as for example in the English fourj^enny stamps of 1855-6. Another form of protection which has been applied to paper for postage stamps and postage envelopes consisted of the insertion in the jDulp of threads of cotton, linen or silk. The chalk surfaced paper now so extensively used for postage stamps, including the Egyptian stamps, also constitutes a protection against the fraudulent removal of the cancellation marks. Any special marking of postage stamjDS by the police for identification purposes is usually done with invisible ink which is afterwards developed. By arrangement with the police, marked stamps are sometimes sold to a person who is suspected of being the author of anonymous correspondence, and the letters are stopped in the post and the stamps examined. Sealing Wax. The addition to sealing wax of a special ingredient, which can easily be tested for, has been suggested as a means of detecting false seals. INDEX Acid, nitric, fire caused by, 118 ,, sulphuric, explosion, caused bv, 108 Aconite, 33, 148 Aconitine, 148 Adulteration of beer, 33 „ potable spirits, 21 „ tobacco, 170 ,, wine, 32 Age of documents, 68 „ ink, 77 ,, windows, 44 Alcoholic liquors, 19 Alterations and erasures, 84 Aluminium, use of, in bullets, 47 Amberite, 128 Ammonia, developing secret writ- ing with, 95 „ presence of, in fresh water, 150 „ presence of, in sea water, 150 Ammonium sulphide, developing secret writing with, 95 Analysis of bullets, 48 ,, potable spirits, 31 Analyst's certificate, 139 Aniline blue, 76 „ dyes, 79 „ ink, 83 Anonj'mous documents, 91 Antiquities, 35 Antimony, use of, in projectiles, 46 Apes, mummy, hair of, 113 Arabic names, 88 ,, writing, 91 Arak, 29 Armour-piercing bullets, 47 Arsenic, use of, in small shot, 47 „ smallness of amount cap- able of detection, 146 ,, sulphide of, use as poison, 147 ,, tests for, 146 Assay of gold and silver, 140 ,, punches, foreery of, 141 Axite, 128, 131 Balnh, 29 Ballistite, 128, 130, 131 Banana leaves, use of, for adulter- ating tobacco, 170 Banknotes, colouring of, 172 „ forgery of, 89 ,, secret marks on, 172 Barium nitrate, use of, in gun- powder, 128 Barrel of gun, examination of, 131 Beer, 32 Benzidine, use of, in blood testing, 39 Bhang, 142 Bismark brown, 79 Bismuth nitrate, secret writing with, 98 Bitumen on mummies, absence of, 38 Black powder, 122 Blasting powder, 107 Blood stains, 39 ,, tests for, 39 Blue ink, 76 Blue-black ink, 76 Bodies, old Egyptian, 54, 121 Book for notes, 5 Bombs, 104 Bonax, 130 Brandy, 19 Bricks, testing of, 40 Brown, Bismark, 79 Building materials, 40 ,, stone, disintegration of, 45 Bullets, 46 Butter, adulteration of, 138 fat, 138 Cannabis indica, 142 ,, saliva, 142 Carbolic acid, 149 Carbon, as pigment, 37 ,, dioxide in gases from gunpowder, 123, 129 ,, monoxide in gases from gunpowder, 123, 129 ink, 74, 79 13 177 178 LEGAL CHEMISTRY Cartridges, 104 Castor oil, invisible writing with, 98 ,, wrongly described, 38 Cement, testing of, 45 Certificate, analyst's, 139 Charas, 142 Charcoal, spontaneous combustion of, 118 ,, use of, in gunpowder, 122 Chejnical development of secret writing, 95 Chemist in Court, 13 Chemistry and criminal investiga- tion, 15 ,, value of, 15 „ legal, 1 Cheques, safety devices in, 172 Chlorides in fresh water, 151 ,, sea water, 151 ,, sewage, 151 Cigarettes, hashish in, 142 Clothes, state of preservation of, 54 Clothing, clues from, 51 Cobalt, occurrence of, in Egypt, 37 ,, in Egyptian pigments, 37 Cognac, 20 Coins, counterfeit, 57 ,, secret marks on, 173 Coir, 165 Colocass, use of, for adulterating tobacco, 170 Combustion, spontaneous, 118, 121 Concrete re-inforced, 41 Copper compounds, use of, as pig- ments, 37 ,, use of, for bullets, 47 ,, -nickel alloy, use of, for bullets, 47 Cordite, 128, 131 Corrosion of iron, 41 Cotton, determination in fabrics, 107 ,, fires in, 118 ,, use of, for paper-making, 69 ,, state of preservation of, 54 ,, ropes of, 165 Criminals, traps for, 171 Crops, damage to, 63 Damage to crops, 63 Date of gold and silver ware, 141 Datura, use of, as poison, 148 Density of coins, 59 Deoilatories, 147 Developers for secret writing, 93 Development of secret writing, chemical, 95 ,, of secret writing, mechanical, 96 Dies, coinage, 58 Discoloration of documents, 71 Dociunents, 65 Drugs, analysis of, 139 Dust and dirt, 102 Dyes, old Egyptian, 37 Dynamite, 106 Eau-de-vie, 20 de vin, 20 Electrolysis, agent in corrosion of iron, 41 Eley's powder, 130 Envelopes, detection of opening, 154 ,, prevention of opening, 173 Eosin, 77 Erasures and alterations, 84 Esparto, use of, for paper-making, 69 Essences, 30 Experts, handwriting, 87 ,, chemical, 1 Explosions, 104 Explosives, 104 Extracts for flavouring alcoholic liquors, 30 Evidence, oral, 13 ,, written, 1 1 Fabrics, textile, 160 Fallacies regarding milk calcula- tions, 135 ,, „ potable spirits, 33 Ferric chloride, use of, for develop- ing secret writing, 95 Ferrous-sulphate, use of, for de- \eloping secret writing, 95 Fibres, 108 Finger prints, examination of, 114 ,, to obtain, 173 * Firearms, examination of, 122 Fires, 117 Fish and sewage, 152 Flax, 165 Foods and drugs, analysis of, 134 Forgery of antiquities, 35 ,, documents, 66 Fuchsine, 77, 174 Ganja, 142 Gases from gunpowder, composi- tion of, 123, 129 Gelignite, 105 Gin, 28 Girders, corrosion of, 43 Gold, assay of, 140 „ old Egyptian, 36 INDEX 179 Green ink, 79 ,, malachite, 79 Guns, examination of, 131 Gunpowder, composition of, 122 ,, products formed from, 123 Guiacum, use of, in testing for blood, 39 Gunshot marks on clothing, 163 HiBmatite, as pigment, 37 Hnemin test for blood, 40 Hair, colour of, in mummies, 110 Hall-marks, forgery of, 141 Handwriting, 87 Hashish, 142 Heat, uso of, as developer of secret writing, 95 Hemp, 165 ,, Indian, 142 Hofmann's violet, 79 Honey, castor oil mistaken for, 38 Hydrogen in gases from gunpowder, 123, 129 Hyoscyamine, 148 Hyoscyamus, 148 Human remains, state of preserva- tion of, 54 Imagination, vise of, 10 Incendiary bullets, 47 Indigo, use of, by ancient Egyp- tians, 38 Infernal machines, 104 Ink, 74, 174 aniline, 83 carbon, 74, 79 logwood, 79 red, 77 safety, 174 violet, 83 containing special ingredients, 174 Inspection of premises, 2 Iodine, use of, for developing secret writing, 95 Iron, corrosion of, 41 ,, oxide of, in re-inforced con- crete, 41 ,, oxide of, in gun barrels, 126 ,, sulphide of, in gun barrels, 126 Jute, 165 Kerosene, fires caused by, 117 Koniak, 21 Lead, use of, in projectiles, 46 „ sulphide of, in gun barrels, 126 Legal chemistry, 1 Lemon juice, secret writing with, 95 Letters, forged, 86 ,, robbery from, 153 Light as developer of secret writ- ing, 94 Linen, vise of, for paper-making, 69 Liqvieurs, 29 Liquid fuel, fire caused by, 117 Liquors, alcoholic, 19 Logwood ink, 79 Machines, infernal, 104 Magnesium, use of, for bullets, 47 Maize fibres, use of, for adulterat- ing tobacco, 170 Malachite green, 79 Margarine, ear-making of, 174 Marks, secret on banknotes and postage stamps, 172, 175 ,, of shot on clothing, 163 ,, and stains, 161 Marsh test for arsenic, 146 Mastic, 29 Mauve, 79 Maybrick case, 7, 145 Mechanical development of secret writing, 96 Mercury perchloride, 148 Methane in gases from gunpowder, 123 129 Microscopy, 1, 39, 68, 101, 109 Milk, adulteration of, 134 ,, secret writing with, 95 Milling on coins, 58 Monson case, 49, 51, 128 Moulds, coinage, 35, 57 Mummies, 10, 54, 111, 121 Names, Arabic, 88 Natron, use of, in mummifying, 10 Nickel -copper coating for bullets, 47 Nlcotiana Tabacum, 171 ,, rustica, 171 Nitrate, potassivim, use of, in gunpowder, 122, 128 Nitrate, sodium, use of, in gun- powder and blasting powder, 107, 122 ,, sodium, files due to, 120 ,, barium, use of, in gun- powder, 128 ,, in gun barrels, 124, 127, 130 Nitrates in water, 150 Nitric acid, fire caused by, 118 Nitrite in gun barrels, 124, 127, 130 180 LEGAL CHEMLSTRY Nitrites in water, 150 Nitro-cellulose, 128 Nitroglycerine, 106, 128 Nitro-lignin, use of, in gunpowder, 128 Nitro-powders, 128 Nitrogen, in gases from gunpowder, 123, 129 Nobel's Empire powder, 130 Note-book, kind of, 3, 5 „ use of, 5 Notes, taking of, 10 Oath, taking of, 8 Ochre, red, use of, as pigment, 37 ,, yellow, use of. as pigment, 37 Oil fuel, 117 ,, sesame in margarine, 174 Onion juice, secret writing with, 96 Opium, 148 Oral evidence, 13 Oxide of iron in re-inforced con- crete, 41 ,, ,, in gun barrels, 126 Oxygen, dissolved, in water, 151 Paper, 68 ,, hand made, 69 ,, machine made, 69 ,, security, 172 Papyrtis, 69 Paraffin, 117 Parcels, robbery from, 153 Parchment, 69 Pellets, 47, 49, 50 Pens, 87 Perchloride of mercury, 148 Phosphorus, fire due to, 118 Photographs as evidence, 12, 60, 83, 100, 115, 164 Photography, 2 ,, of coins, 60 ,, of seal impressions, 100 Pickpockets, 174 Pigments, old Egyptian, 37 Pitch, wood on mummies, 38 Plants and tar, 65 Poisons, 145 Pollution of water by sewage, 150 Ponceau scarlet, 77 Postage stamps, 90, 175 ,, ,, secret marks on, 175 Postal orders, protection of, 175 Potassium carbonate in gun bar- barrels, 123 „ disulphide in gun bar- rels, 123 Potassium, ferricyanide, use of, for developing secret writing, 95 ferrocyanide, use of, for developing secret writing, 95 nitrate, use of, in gun- powder, 122, 128 nitrate in gun barrels, 124, 127, 130 nitrite in gun barrels, 124, 127, 130 sulphide in gun barrels, 123, 127, 130 sulphate in gun barrels, 123, 127, 130 Potato-starch, use of, in margarine, 174 Powder, black, 122 ,, blasting, 107 ,, smokeless, 128 Powders, coloured, use of, 90 Premises, inspection of, 2 Preservation of buried articles, 54 Projectiles for guns, 46 Rags, use of, for paper-making, 69 Rat poison, 118 Re-agents, purity of, 7 Red ink, tests for, 77 Registers, examination of, 85 ,, use of, 4 Reinsch test for arsenic, 145, 146 Remington smokeless powder, 130 Report, nature of, 1 1 Results, commimication of, 1 1 Robberj' from letters and parcels, 153 Rods, iron, corrosion of, 41 Rope and string, 165 Rum, 27 Rust in gun barrels, 124 ,, re-inforced concrete, 41 Sacks, clues from, 167 Safe, robbery from, 102 Salinometer, use of, 151 Saliva, secret writing with, 96 Salt in building stones, 46 ,, re-inforced concrete, 42 ,, use of, for secret writing, 96 Samples, treatment of, 5 Sand, kinds of, 103 Scarabs, forgery of, 37 Schultze powder, 128 Seal impressions, ink, 99, 160 wax, 101, 154 Sealing-wax, 155, 175 Secret marks on coins, 173 ,, ,, banknotes, 172 INDEX 181 120 gun- and Secret marks on postage stainps, 175 ,, writing, 92 Seddon case, 12 Sepia, use of, as ink, 68, 79 Sesame oil in margarine, 174 Sewage, pollution of water by, 150 ,, piirification of, 152 Shot, small, 46 ,, marks, 163 Signatures, questioned, 83, 89 Silver, assay of, 140 ,, old Egyptian, 37 ,, nitrate, use of, for develop- ing finger prints, 115 Silk, determination in fabrics, 167 Sludge, sewage, 152 Slugs, 46, 50 Smethurst case, 145 Smokeless powder, 128 Sodium nitrates, fires due to, ,, ,, use of, in powder blasting pow- der, 107, 122 Solutions, coloured, use of, for developing secret writing, 96 Sovereigns, counterfeit, 57 ,, sweated, 62 Specific gravity of coins, 59 Spirits, potable, 19 Spontaneous combustion, 118 121 Stains, blood, 39 ,, and marks, 161 Stamps, post office cancellation, 90 „ postage, 90, 175 ,, ,, secret marks on, 175 Stone building, disintegration of, 45 Straw, use of, for paper-making, 69 String, 165 Sugar, secret writing with, 95 Sulphide, arsenic, use of, as jaoison, 147 ,, potassium, in gun barrels, 123, 127, 130 ,, iron, in gun barrels, 126 „ lead, in gun barrels, 126 120, Sulphides in gun barrels, 124, 127 Sulphur, in gun barrels, 123 Sulphuretted hydrogen, in gas from gunpowder, 123 Sulphuric acid, explosion caused by, 108 Tannic acid, use of, for developing secret writing, 95 Tar and plants, 65 Textile fabrics, 166 Tin, use of, in projectiles, 46 Tobacco, 169 Tombac, 171 Touchstone, assay by, 141 Toxicological analysis, 145 Traps for criminals, 171 Tungsten, use of, for bullets, 47 Urine, secret writing with, 95 Vellum, 69 Violet, Hofmann's, 79 ink, 83 Wads, examination of, 49 Walsrode powder, 128, 130, 131 Water, use of, for developing secret writing, 98 Water-marks in paper, 70 Water, pollution of, by sewage, 150 Wax-seal impressions, 101, 155 Wax, sealing, 155, 175 Whisky, 24 Wigs, colour of, 113 Windows, age of, 44 Wine, 32 Wood-pitch, 38 Wood-pulp, mechanical, 69 ,, soda, 69 ,, sulphite, 69 Wool, determination of, in fabrics, 167 ,, preservation of, 54 Writing, Arabic, 91 ,, experts in, 87 illegible, 91 ,, secret, 92 Zebib, 29 NOTES NOTES NOTES Printed in Great Britain by CNWIN BROTHERS, LIMITED, PRINTERS, WOKING AND LONDON . ■ ^..,. /'>i'^T ' UNIVERSITY OF CALIFORNIA LIBRARY BERKELEY Return to desk from which borrowed. This book is DUE on the last date stamped below. y*i4\'N0V8 1971 JUN 5 1975 f JUN 1 31S75 LD 21-100TO-7,'52(A25288l6)476 C fj ) / ^^^^-—X , h /^r U.C. BERKELEY LIBRARIES CDET31bnD UNIVERSITY OF CALIFORNIA LIB^'^y