Page:The New International Encyclopædia 1st ed. v. 19.djvu/447

* TOXICOLOGY. 389 TOXIN. as a habit by a few individuals. See An.es- TIIETIC. Gaseoi'S Poisons. The more common of these are carbonic acid gas. carbon monoxide, hydro- gen sulphide, sulphurous oxide, illumiiuiting gas, sewer gas and cesspool emanations, and carbonic acid gas (choke-damp) as found in the air of mines, cellars, and wells. Miners are frequently killed by the latter. Carbon monoxide occurs in charcoal fumes, fuel gas. and illuminating gas, and passes into the air of a room from defective fiues or pipes. Air containing 1 per cent, of this gas is rapidly fatal. When exposure to this poison has been long and unconsciousness exists, recovery is not probable. The effects of illumi- nating gas are similar to those of carbonic oxide. Sewer gas is a mixture of sulphureted hydro- gen, ammonium sulphide, nitrogen, and carbonic acid gas. The symptoms of the gaseous poisons de]icnd on the amount absorbed and vary from slight headache and dizziness to suffocation and collapse. The treatment is to get the patient into the fresh air, give oxygen, or perform arti- ficial respiration, and stimulate. Animal Poisons. The stings of insects, the bites of scorpions, tarantulas, snakes, and rabid dogs, are comprised in this group. Their action is complicated. The local effects are irritation, redness, swelling, and oedema, or even gangrene. The poison after entering the circulation may disorganize the blood, causing jaundice, haemo- globinuria, hemorrhage into the tissues, and cyanosis. There are in addition general .symp- toms, such as vertigo, dyspmea, prostration, car- diac paralysis, and finally collapse. The local treatment of such bites consists in the applica- tion of a tight band or ligature above the wound to prevent absorption; the destruction by the knife or cautery of the area containing the poison after removing as nuich as possible by suction ; and the administration of stimulants such as ammonia, alcohol, or strychnine, to keep up the strength until the poison is eliminated. Quite recently a serum known as antivenene has been given in snake-bites with excellent results. See Glanders ; HvDROPiioniA ; Scruji Therapy. The medico-legal duties of the medical examin- er in cases of fatal poisoning, whether suicidal or homicidal, arc: ( 1 ) to establish the presence or absence of conditions characteristic of any poison; (2) to preserve all necessary material for subsequent analytical examination, and to avoid introducing possible causes of error; (3) to recognize or exclude natural causes of death ; (4) to perform experiments on animals, if neces- sary, in order to demonstrate the toxic effect of the substance separated by the chemical ; and (5) to record carefully all observations and state clearly the conclusions as to the cause of death. Difficult cases constantly arise in w-hich the post-mortem appearances are not decisive, or are consistent either with disease or poison. In performing an autops}' for medico-legal pur- poses, the identity of the body must first be es- tablished and the autopsy should be done in the presence of witnesses. The organs and tissues to be removed and preserved for future analysis are deposited separately in clear glass jars, which are sealed. The tissues and organs to be removed are the stomach, and intestines ligated and unopened; the entire liver: the blood from the heart and vessels ; both kidneys ; the urine ; the entire brain; a large piece of muscle from the thigh; and portions of the Done and spleen. Important infornuilion as tci the time of absorp- tion is evidenced by the distribution of poison in the various tissues. The unabsorbed residue is found in the stomach and intestines. Poisons in both stomach and liver indicate a short in- terval between the taking and death; while poison in the liver and other organs, with none in the stomaeh, indicates a greater interval. Host poisons remain in the liver after disajjpcaring from the stomach and remain longer in the muscles and bones than in any other tissue. Poisons are found in their greatest purity in the kidneys and urine. Proof of poisoning has been established by chemists by analysis of muscles or one kidney, when all the other tissues have been destroyed by the suspected parties. Be- sides the examination for poisons and their lesions, every organ must be examined for all natural causes of death, and in particular the causes of sudden death should be rigidly ex- cluded. Consult : Witthaus and Becker, .Medical Jurispruflcncc, Forensic Medicine, and To.ticol- ogii ( Xew York. 1S'.I4) ; Peterson. Lcyal Medicine and Toxicology (Philadelphia. 1903); Brundage, A Manuiil of Toxicology (New York, 1901). See Autopsy; Medical Jurisprudence. TOXIN. A specific bacterial poison whose absorption into the body causes an infectious dis- ease. Though formerly used, as suggested by Brieger, to designate the poison members of the ptomaine group (see Ptomaines) of bacterial bases, it was fortunately not so restricted. Tox- ins are not albumins ; they are not proteid bodies. It had been surmised that the symptoms present during diseases induced by microorganisms were due to the basic poisons known as ptomaines. But after using in experiments these bases, it was learned that this was untrue. The ptomaines are not as potent as certain chemical products of the bacteria. Moreover, in the highly poisonous cultures of certain germs no ptomaines have been formed. This statement is true of diphtheria, as confirmed by Loeffler. Eoux and Y'ersin, Brieger and Friinkel. Some of these investigators estab- lished the additional fact that the toxins are formed liy synthetical i)rocesses. and not by splitting up the constituents of the culture medi- um or those of the animal body. The germ ap- parently constructs its toxin out of the com- ponents of a harmless menstruum. In seeral specific infectious diseases special toxins have been isolated. Marinier extracted a specific toxin from glycerin-peptone cultures of the anthrax bacillus, which does not give the reactions of albuminoid substances nor change starch, sugar, or glycogen. Animals immune to anthrax bacil- lus are immune to this toxin. Alkaline hypo- chlorites, as well as prolonged isolation in the jires- cnee of air. destroys its efficacy. Animals uiiiy be immunized to anthrax if treated with care- fully graduated dosen of this toxin. This toxin is contained in the bacterial cells of anthrax and the culture must be so adapted that oppor- tunity is oft'ered for it to diffuse from the cells. Similarly, the presence of a toxin derived from the comma bacillus has been demonstrated in Asiatic cholera, as also a toxin in tetanus, diph- theria, typhoid fever, and tuberculosis, while in sup|iuration the poisoning is due to toxin derived from the bacillus staphylococcus. Susotoxin has