process for Arsenic, that for Mercury, and that for Opium; but some improvements have also been suggested in the mode of detecting Copper, Lead, Zinc, and Oxalic Acid. In one chapter, that on Lead, I have extended my remarks on the chemistry of the subject farther perhaps than was called for in a strict treatise on medical jurisprudence. I had made some experimental researches on the action of various waters on lead; and as the results appeared to me interesting, and form an essential part of a kindred branch of knowledge, medical police, I conceived that a statement of them might not be misplaced in the present work. The Physiological effects of each poison on animals then come under consideration, and are succinctly stated in an inquiry into its mode of action, as preliminary to the detail of its effects on man. In treating of the Symptoms observed in man, I have preferred giving a general account of the effects of each poison to transcribing a list of complete cases, as Professor Orfila has done. I have thus been enabled to communicate more information in much less space, Great care, however, has been taken to specify all the deviations from the usual course of the symptoms, and likewise to classify the ordinary cases according to the leading varieties. In the classification of cases the reader will perceive a few novelties have been introduced, which it is hoped will be found improvements.— Some pains have been bestowed on two points, which systematic writers on poisons have utterly neglected, the shortest and longest intervals within which poisons begin to operate, and the shortest and longest period within which they prove fatal. In relation to these points, questions not infrequently occur in trials, where the fate of the prisoner may de pend on the answers returned by the medical witness*; yet no information of the kind is to be met with in any systematic work on toxicology. In the present treatise, I have attempted to ascertain with precision the commencement and duration of the symp toms of most of the common poisons. But it is necessary to observe, that precise information as to these points is not often to be found in the narratives of cases; and hence that in all probability some of the statements made in this work will subsequently require to be modified. Another point which it has been considered proper to investigate with more care than has hitherto been attempted, is the diagnosis between poisoning and natural disease, as founded on symptoms only. Almost all modern writers on medico-legal toxicology have declared such diagnosis impossible; and their opinion is undoubtedly correct, as a general rule. But at the same time, the more the subject is inquired into, the more strongly does it appear to me that the rule admits of certain special exceptions, which it is of great consequence to indicate distinctly †. It was perhaps natural, that the former loose practice of deciding questions of poisoning almost always from symptoms only, should not be corrected without passing as far into the opposite extreme. But it is now time to return to the mean, where, as in other matters, the truth may be presumed to lie. This I have attempted to do; without the presumption, however, of thinking that future experience will not render necessary some modification of the opinions here hazarded. It would be surprising if no errors were committed upon questions which must be decided, not by one • See cases of Smith, 216; Freeman, 565; Russell, 220; Crown Prince of Sweden, 40. + See pages 123, 151, 239, 321, 644. man's experience or reading, but by the experience and learning of the whole medical profession. The subject of the Morbid Appearances left in the dead body by poisons, has been considered nearly in the same manner with the preceding topic. Every ap pearance mentioned by good authorities has been noticed, even where the accounts of different authors are apparently contradictory; and an attempt has sometimes been made to reconcile the discrepancies, by classifying the appearances according to certain varieties in the features of the cases during life. In this department of the work much difficulty has been encountered, from the vague and incorrect language often used by authors. In some instances, I have endeavoured to show that the morbid appearances will, when taken alone, form the grounds of a diagnosis between poisoning and natural disease. Such cases, however, must be admitted to be rare. To these strict medico-legal investigations, a short view has been annexed of the Treatment of the principal varieties of poisoning. To the physician this is of obvious utility, and to the medical jurist it is necessary, in order that he may be able to answer questions as to the treatment in particular cases. Throughout the whole work, I have turned my personal experience as much to account as was in my power. But in medical jurisprudence, more than in any other medical science, the experience of any single individual, how great soever it may be, is but a feeble light to guide his steps, when compared with the vast accumulated stores of the records of medicine. These I have made use of to the best of my ability; and I have had such unbounded access to authorities, that the chief toxicology, and have never been considered in works on poisons. Among these may be specified the subject of pseudo-morbid appearances, and that of the signs, causes, and circumstances of natural death. Orfila first introduced, and several authors have copied from him, a long methodical table of all poisons, with their properties so arranged, that a suspected substance might, by a successive comparison of its qualities, be referred to its proper head among them. But as in nineteen cases out of twenty the poison is presented to the medical jurist in so impure a state that this mode of examination is inapplicable, and as it is very doubtful whether an unknown poison is ever in actual practice found out in such a manner, I have omitted the table altogether. By moral evidence and the consideration of the symptoms, the particular poison is always indicated presumptively; and the analysis is directed by this presumption. CONTENTS. CHAPTER I. Of the Physiological action of Poisons, SECTION 1. Of their mode of Action, Of the discovery of Poisons in the Blood, 2. Of the causes which modify their Action, Application of the preceding observations to the CHAP. II. Of the Evidence of General Poisoning, SECTION 1. Of the Evidence from Symptoms, Characters of the symptoms of Poisoning, Characters of the symptoms of Natural Disease, 2. Of the Evidence from Morbid Appearances, 3. Of the Evidence from Chemical Analysis, 4. Evidence from Experiments on Animals, With suspected articles of food or drink, With vomited matter or contents of the stomach, Suspicious conduct of prisoner, 62 and 71-Proof of administration of poison, 63—Proof of intent, 66-Proof from simultaneous illness of several PART SECOND.-OF INDIVIDUAL POISONS. CHAP. I. Classification of Poisons, CHAP. II. CLASS FIRST. Of Irritant Poisons generally, |
