ALKALOIDAL AND OTHER ORGANIC POISONS. BY WALTER S. HAINES, A.M., M.D. 1. ALKALOIDAL POISONS. The term alkaloid is used with somewhat varying significance by different authorities; but as commonly employed it refers to the bases or alkali-like bodies found in many plants, to which the latter as a rule owe their physiological effects. They are often spoken of as plant bases. The total number known is large, and embraces some of our most valuable remedial agents, and not a few of our most active poisons. There are many properties common to all, or to nearly all, of the different members of the class, and these may advantageously be considered together before taking up the individual substances. Composition. All alkaloids contain carbon, hydrogen, and nitrogen, and all but a few contain oxygen also. The major portion of them, therefore, do not differ from one another in the elements of which they are composed, but only in the relative proportion of these elements. The chemical formulas of a few of the most important toxic alkaloids are as follows: Physical and Chemical Properties.-Alkaloids containing oxygen are fixed solids, while those containing no oxygen are volatile liquids. They are generally crystalline, devoid of color, and are usually possessed of a bitter or pungent taste. The volatile alkaloids have a pronounced odor, but those that are fixed are odorless; they are generally of alkaline reaction to litmus, and combine with acids, neutralizing them and producing salts. The free alkaloids are, as a rule, either insoluble or difficultly soluble in water, but they generally dissolve with readiness in alcohol, ether, chloroform, and benzine, and in many other organic liquids. Their salts, on the other hand, are usually readily soluble in water, especially when slightly acidulated, and also in alcohol, but ordinarily they do not dissolve in ether, chloroform, or benzine. These differences in the solubility of the free alkaloids and their salts are taken advantage of, as we shall see later, in the extraction of alkaloids from complex organic mixtures. Like the majority of organic substances, most of the alkaloids are unstable bodies, undergoing complete or partial decomposition under a great variety of conditions. All of them when heated considerably above the boiling-point of water, and sometimes at a much lower temperature, are prone to undergo change; as a rule, strong acids and alkalies and active oxidizing agents decompose them; and they all appear under suitable conditions to be acted on by micro-organisms, which eventually cause their complete decomposition. For these reasons it is highly necessary in extracting alkaloids not to subject the materials under examination to too high a degree of heat, nor, as a rule, to bring them in contact with strong acids, alkalies, oxidizing agents, or other powerful chemicals. Failure to observe these precautions can easily lead to negative results, even though an alkaloid be present in the suspected substance. For the same reason, after death by poisoning by an alkaloid the latter sooner or later disappears from the body by decomposition. This is probably brought about chiefly through the agency of micro-organisms, which swarm in the decomposing body. It is very important, therefore, to examine for alkaloidal poisons as soon after death as possible; the longer the examination is put off, the smaller the chance of detecting the poison. Most alkaloids when in solution are rendered insoluble and precipitated by a number of chemical compounds, which are known, consequently, as general precipitants or reagents for alkaloids. The most important of these are tannic acid, picric acid (Wormley's reagent), phosphomolybdic acid (Sonnenschein's reagent), iodine dissolved in a solution of potassium iodide (Wagner's reagent), and potassio-mercuric iodide (Mayer's reagent). The last two are usually the most valuable, and both are of great service as general tests for the presence of an alkaloid. If neither of these reagents produces a precipitate in a suspected solution, we generally say with great certainty that no alkaloid is present; if, however, they do occasion a precipitate, the presence of an alkaloid may be suspected, although not positively demonstrated, as sev eral other substances are precipitated in a similar manner. These tests, therefore, have chiefly a negative value, but this is frequently of great importance. Wagner's reagent may conveniently be prepared by dissolving one part of iodine and two parts of potassium iodide in ninetyseven parts of water, and Mayer's reagent for qualitative purposes may be similarly made by dissolving one part of mercuric iodide and two parts of potassium iodide in ninety-seven parts of water. The precipitates given by Wagner's reagent are reddish or reddish brown, while those produced by Mayer's reagent are generally yellowish white. Many of the alkaloids when subjected under appropriate conditions to certain chemical agents produce characteristic colors, and advantage is extensively taken of this fact in the recognition of a large number of the alkaloids. Such reactions are known as color tests. For example, if strychnine is treated with strong sulphuric acid, and a crystal of potas sium bichromate, or other oxidizing agent, is drawn through the mixture, a very brilliant play of colors ensues, beginning with blue and ending with red. Similarly morphine, colchicine, atropine, and many other alkaloids develop more or less characteristic colors when treated with different chemical reagents, especially those of an oxidizing character. As before stated, extensive advantage is taken of these color reactions in testing for the presence of alkaloids, and they are of the greatest utility in toxicological investigations. When properly conducted they are entirely reliable, and may be depended upon with great certainty; but if not performed with skill, or if the observer is decidedly color-blind, they may be worse than useless, and may lead to most unreliable results. In connection with the several alkaloids, hereafter to be considered separately, the color tests for each will be described, and the precautions to be observed in obtaining them dwelt upon. Symptoms Produced in Case of Poisoning.-The alkaloids as a rule produce their poisonous effects rapidly; sometimes the symptoms begin immediately after their administration, and they are rarely delayed for any considerable length of time. After the toxic symptoms begin to show themselves they generally progress rapidly, with increasing violence, and unless relief is obtained death promptly ensues. There are many marked exceptions to this rule, especially in connection with morphine, whose effects are often slow in manifesting themselves, and sometimes persist many hours before leading to a fatal termination. Rapidity of action is somewhat characteristic of the alkaloids, and in a general way distinguishes them from most of the mineral poisons, which usually are slower in producing their effects. The poisonous alkaloids as a rule exert their chief influence upon the nervous centers, and the symptoms, therefore, in the main, are those referable to the nervous system. verted action of the heart and of the respiratory organs, disorders of vision, perverted sensation, convulsions, paralyses, and coma are among the most common symptoms shown. With a few exceptions, chiefly in connection with colchicine and veratrine, violent vomiting and purging are not usually seen, and in this respect alkaloidal poisoning differs from the toxic effects of most of the mineral poisons, which as a rule occasion pronounced emesis and diarrhoea. As the effects of the poisonous alkaloids are chiefly directed to the nervous system, the diseases with which they are likely to be confounded are naturally those in which the nervecenters are involved, such as tetanus, epilepsy, apoplexy, hysteria, étc. Per Treatment. Since the alkaloids generally act rapidly, prompt treatment must be resorted to if favorable results are to be secured. As in all other cases of poisoning, the stomach should be evacuated, either by emetics, or by the stomach-pump or stomach-tube, and the organ thoroughly washed out with tepid water. In the absence of means of evacuating the stomach promptly, or even in connection with such means, substances should be given which will render the alkaloid less soluble, and consequently retard its absorption. The most valuable of these are tannic acid, and iodine dissolved in potassium iodide (the official compound solution of iodine of the pharmacopoeia). Finely pulverized charcoal has also been highly recommended, and it undoubtedly may sometimes be useful by mechanically uniting with the poison and slowing its absorption. It has at least the merit of being harmless. After removing from the stomach whatever portion of the poison is still there, the treatment should be addressed to the constitutional symptoms; and as these are commonly produced through perverted action of the nervous system, |