Forensic science laboratories.

FROM the earliest times the two main methods of criminal killing appear to have been, and still are, by the use of (a) weapons; (b) poisons. It will be readily admitted that with the development of civilization there has been a very considerable change and augmentation of the resources of the criminal, not only in weapons-from bludgeon to firearms, etc., but also in poisons, from snake venom and poison pot to toxic chemicals; the technique of the criminal has also undergone marked development. In fact, in many major crimes, evidence of scientific skill and knowledge on the part of the criminal has often been manifested. Poisoning seems to have exerted some degree of fascination for the human race. Early history records many cases of death by criminal poisoning, also the production of alleged antidotes. Thus, Sir William Willcox records] that in the first century B.C., Mithridates conducted toxicological experiments on condemned criminals and others and invented a universal antidote alleged to have contained 36 ingredients. He himself became so immune to poisons that, wishing to commit suicide, was compelled to ask a mercenary to kill him with his sword. Poisoning became a fine art, political murders by poison developed to such a degree that it became the practice of kings and persons in high office to protect themselves by having" tasters" of both food and drink, a portion being removed and tasted in the presence of, and immediately before consumption, by the person or persons to be safeguarded. Although poisoning in England was not as prevalent prior to 1500 as on the Continent, it did exist; thus it is recorded that Henry VIII ordered poisoners to be boiled to death. After this, "criminal poisoning" developed fairly rapidly and became quite common up to the nineteenth century-the chief poisons were probably preparations containing arsenic and corrosive sublimates. The methods of diagnosis of poisoning were very limited, depending very largely on observations before and during illness prior to death, together with post-mortem appearances. Thus the scientific investigations relating to poisoning cases (i.e., toxicology), were undertaken by qualified medical men, and included in the field known as Forensic Medicine or Medical Jurisprudence. The development of toxicology was in some measure restricted and controlled by the advances in modern chemistry and reliable analytical methods, and ran parallel with developments in forensic medicine. (There are still, however, some who still claim that toxicology is included in forensic medicine.) The foundations of toxicology were laid towards the end of the eighteenth and nineteenth centuries. Thus we have the discovery by Scheele of arsenic (1775), hydrogen cyanide 1783, the Marsh test for arsenic 1836. The detection of arsenic in the alimentary tract and organs by Orfila (1839) indicated the importance of a determination of the degree of absorption of this poison. The first systematic description of chemical tests for poisons in Britain appear to have been given by Christison in his Treatise on Poisons (1829)' In 1844, Fresenius and von Babo devised a scheme