Page:Popular Science Monthly Volume 39.djvu/501

Rh method of distinction, which, consists in breaking up the corpuscles. By means of a little acetic or sulphuric acid this may be accomplished, and then on slowly evaporating the solution we get crystals characteristic of the animal to which the blood belonged. By combining these two methods blood can be identified, not with absolute certainty, but with a high degree of probability.

However, probability is not enough. In a question where a man's life is at stake something more is demanded. Not probability merely but absolute certainty alone can satisfy the people. This in many cases we have. In 1852, in Essex, England, a man was tried for the murder of a woman. She had been found dead in her bed, with her throat cut from ear to ear. Among the prisoner's possessions was found a razor clotted with blood, and in the blood were detected two or three short cotton fibers. Taken and examined microscopically and compared with the clothing of the woman, it was found that in cutting her throat the assassin had cut through the strings of her night-cap, and these minute fibers of that remained as the silent witnesses of his guilt.

Sometimes mud or dirt adherent to clothes connects a person with crime, or a hair sticking under the nail of a boot may by comparison show that its possessor has trampled upon the head of the deceased; or, as in a case at Hull, England, the Diatomaceæ adhering to a man's shoes proved that he had been at the place where the murder had been committed.

Such are some of the ways in which the microscope aids us in ferreting out the assassin. It has, however, a wider application. Some years ago Ehrenberg, that old prince of microscopists, was employed by the Prussian Government to investigate a case of smuggling. A cask had been opened, valuables extracted, and the cask repacked, and shipped onward to its destination. The only clew to the criminals was that the unpacking must have been done at some of the custom-houses through which the goods passed. To all appearance, the microscope had a hopeless task. But not so. Ehrenberg took some of the sand that had been used in the repacking, placed it under his microscope, looked through his magic tube, and behold, there on the stand lay a peculiar specimen of Foraminifera That animal was found at only one place in the known world, and told at just what point the crime had been committed.

The history of England furnishes another illustration of the use of the microscope as a detecter of crime. A few years since the people were very much troubled about adulterations. Not only the tea and coffee they drank, but the food they ate, their medicines, and even their clothing were mixed up with foreign ingredients. In some cases this was carried to such an extent as to be simply diabolical. Wisely and well did the Government act.