placing the discharged pistol in his hand to give the suggestion of suicide. Experiments were made in which the hand holding the pistol was lifted into the position in which it must have been held if it had been a case of suicide, and in each instance the hand, when allowed to fall, did not retain the pistol. For the defence medical evidence was given that the spasmodic contraction of the muscles after death would account for the pistol being still clenched in the hand, while the inability of the hand to grasp it afterwards did not prove anything. Evidence as to the presence of a motive was given, but the scientific evidence was regarded as decisive and the prisoner was discharged.

The question whether a person who has apparently committed suicide could possibly have made use of the degree of force to which circumstances pointed has frequently arisen.

The most notable instance of the kind was in reference to the Earl of Essex who was found dead in the Tower in July, 1683, his throat having been cut. A razor was lying by his side with its blade notched, and public opinion was strongly divided as to whether he had committed suicide or had been murdered. The medical men who supported the former view explained the notches upon the razor blade as the result of its having been drawn backwards and forwards across the neck bone, although for a suicide to have done this would have been an impossibility.

Occasions have arisen where a chemical expert has been asked to state whether a gun or pistol found lying near a body has or has not been recently discharged.

Even in the case of firearms that had been loaded with black powder no very definite answer can usually be given to this question. Taylor suggested that the presence of potassium sulphide (formed from the powder) adhering to the barrel would indicate that the gun had recently been fired, whereas after a short time this sulphide would become oxidised, and no longer give the reactions of a sulphide. After a longer time traces of iron oxide formed from the iron of the barrel might be expected.

It would not be safe to lay stress upon conclusions based upon such data as these, and at best they could only afford corroborative evidence.

An amusing instance within the present writer’s experience affords another example of the way in which a trifling point being overlooked may be strong presumptive evidence of attempted fraud. A family of the name of, say, Abendessig, effected an insurance against burglary with a company which may be described as the Safeguard Assurance Co.

It was not long before they were the unhappy victims of a burglary in which Miss Abendessig lost several valuable pieces of jewellery including a watch, a diamond ring, and several brooches.

In proof of her claim she produced receipts from the jeweller from whom she stated she had bought these articles, the total value of which was given at £150.

There were three receipts in all, dated at intervals of two or three months, the first being made out to Miss Abendessig and the last to Mrs. Lab, she having been married in the interval, and the second to her father, Simeon Abendessig.

The Safeguard Assurance Co. had a suspicion that the jeweller, who had an address but no shop, was in league with the Abendessigs, and that the first and third receipts had been written at the same time.

The present writer was therefore asked to examine these documents to see whether any evidence of the date of writing could be obtained.

They were both written in blue ink upon common billheads, but the fact that the ink and paper were of the same kind was no proof that they were not genuine receipts.

When, however, the receipt stamps were examined under the microscope it was obvious that the right-hand side of one stamp corresponded with the left-hand side of the other stamp. That is to say, the little projections of paper left when two stamps are torn apart across the perforation exactly coincided in every instance, a long projection on one being matched by a short projection on the other, and so on.

The exact coincidence of seventeen points could not have been the result of chance, and the stamps on the two receipts must therefore originally have been attached to one another in the sheet.

The further inference was that the jeweller must either have torn them apart and put one on the earlier receipt and the other on the later one at the same time, or he must have had the second stamp put aside for three months and then affixed it to the later receipt.

A much more obvious slip than this was made some years ago in a bogus claim upon a fire insurance company, the story of which is related in Lord Brampton’s “Reminiscences.” The fire broke out on the premises of a firm of tailors, and it was claimed by them that the whole of their stock, including many hundred pairs of trousers, had been destroyed.

The insurance company, after examining the burnt-out building, instructed a number of their agents to sift carefully the whole of the ashes.

At the hearing of the case the counsel for the company remarked that it was strange that in a fire in which so many pairs of trousers had been burned the metal buttons upon them should not have been found.

On the next day the tailors appeared with a whole bucketful of buttons, but their production was too late to be convincing, for the ashes had been thoroughly sifted before the claimants attempted to make good their oversight, and only a very few trouser buttons had been discovered.

On the other hand, the danger of jumping to a sudden conclusion from circumstances has been frequently demonstrated. Thus, a very extraordinary case in which some facts that clearly pointed to the guilt of a prisoner were found to have misled many witnesses, was tried in 1813 at the assizes at Bury St. Edmunds. A farmer who owned upwards of 1,200 acres was accused of burglary, and as evidence against him it was positively stated that certain articles in his possession had been stolen from the house. The witnesses swore that they had identified some sheets by stains upon them and a cask by the fact of its being marked with the letters P.C. 84 in a circle. For the defence, witnesses stated that the prisoner was in possession of sheets stained in exactly the same way, and that the cask was one of those in which he had received cranberries from Norwich, all of which casks were marked in the same manner. The prisoner was acquitted.

Scientific testimony is another form of the so-called “circumstantial evidence,” and as such is sometimes looked upon with suspicion. Yet in how few cases is it possible to produce the man who can say, “I saw the deed done,” and even in such cases, what errors of identification may occur! In far the greater number of crimes the proof must depend to a large extent upon the evidence of circumstances. But these must be so convincing that it is impossible in reason to draw any other conclusion from them. In this country it is the duty of the prosecution to prove the guilt, and unless that is done in such a way as to leave no shadow of doubt in the minds of the jury, a prisoner is entitled to be acquitted.

There must be no speculation upon a man’s guilt. A man is regarded as innocent so long as it is impossible to connect to him the last link in a long chain of circumstantial evidence.

In the brief accounts of various celebrated trials in the following pages an attempt has been made to give an outline of the scientific circumstantial evidence that has led to the conviction or acquittal of the prisoners. In some of these trials proof of guilt has been overwhelming, although the testimony of an eye-witness has been lacking, but in others the Scotch verdict of