Every medical man, before presenting himself to give evidence in a case of suspected poisoning, should make himself thoroughly acquainted with recent researches on the subject. Ptomaines are, for the most part, alkaloids generated during the process of putrefaction, and they closely resemble many of the vegetable alkaloids--veratrine, morphine, and codeine, for example--not only in chemical characters, but in physiological properties. They are probably allied to neurine, an alkaloid obtained from the brain and also from the bile. Some of them are analogous in action to muscarine, the active principle of the fly fungus. Some are proteids, albumins, and globulins. Ptomaines may be produced abundantly in animal substances which, after exposure under insanitary conditions, have been excluded from the air. Ptomaines or toxalbumins are sometimes found in potted meats and sausages, and are due to organisms--the _Bacillus botulinus_, the _B. enteritidis_ of Gaertner, the _B. proteus vulgaris_, or the _B. aertrycke_ (which is perhaps the most common of all). The symptoms produced by the latter are usually vomiting, abdominal pain, pains in the limbs and cramps, diarrhoea, vertigo, coldness, faintness, and collapse. The symptoms of _botulism_ are dryness of skin and mucous membranes, dilatation of pupils, paralysis of muscles, diplopia, etc. Articles of food most often associated with poisoning are pork, ham, bacon, veal, baked meat-pie, milk, cheese, mussels, tinned meats. In a case of suspected poisoning, counsel for the defence, if he knows his work, will probably cross-examine the medical expert on this subject, and endeavour to elicit an admission that the reactions which have been attributed to a poison may possibly be accounted for on the theory of the formation of a ptomaine. There is practically no counter-move to this form of attack. INDEX Abdomen, injuries of, 29 Abortifacients, 147 Abortion, criminal, 42 Acetanilide, 136 Acetate of lead, 116 Aconite, 143 Adipocere, 18 Adultery, 62 Age, determination of, 12 Alcohol, 130 Alcoholic insanity, 76 Alkaloids, 93 Alum, 103 Ammonia, 102 Anaesthetics, death from, 19 Aniline, 136 Antifebrin, 136 Antimony, 112 Antipyrine, 135 Aqua fortis, 97 Arsenic, 107 Arsenious acid, 107 Artificial oil of bitter almonds, 137 Arum, 124 Asphyxia, 13 Assaults, 21 Assizes, 7 Atropine, 127 Barberio's test, 58 Barium salts, 104 Belladonna, 127 Bestiality, 59 Bichromate of potassium, 119 Bismuth, 119 Blackmailing, 60 Bladder, injuries of, 30 Blood-stains, 30 Born in wedlock, 52 Botulism, 151 Brain, injuries to, 26 Breslau's life test, 49 Brucine, 146 Bruises, 22 Bullet wounds, 24 Burnett's fluid, 119 Burns, 22 Cadaveric alkaloids, 150 rigidity, 17 Calabar bean, 139 Camphor, 129 Cantharides, 146 Carbolic acid, 100 Carbonic acid gas, 120 oxide, 121 Carnal knowledge, 55 Cellon, 129 Chemical analysis, 91 Chest injuries, 28 Chloral, 134