Alkaloid

“ To eliminate the last traces of ammonia, we place for a few minutes the vessel containing the alkaloid in a vacuum over sulphuric acid, and obtain the organic alkaloid with the chemical and physical characters which belong to it, and which it is now the Chemist’s duty to determine positively. ”

“ I am quite convinced that every Chemist who has kept up his knowledge as to analysis, will not only succeed in detecting their presence, but even in determining the nature of that which he has discovered, provided that the alkaloid in question is one of that class of bodies, the properties of which have been suitably studied. Thus he will be able to discover conia, nicotine, aniline, picoline, petinine, morphine, codeine, narcotine, strychnine, brucine, veratrine, colchicine, delphine, emetine, solanine, aconitine, atropine, hyoscyamine. ”

“ Put some drops of alcohol in the capsule which contains the alkaloid, and leave the solution to spontaneous evaporation. It is, however, very rare that the alkaloid obtained by the above process is pure enough to crystallize. Almost always it is soiled by foreign matters. To isolate these substances, some drops of water, feebly acidulated with sulphuric acid, are poured into the capsule, and then moved over its surface, so as to bring it in contact with the matter in the capsule. Generally we observe that the acid water does not moisten the sides of the vessel. ”

“ The alkaloid is in the form of a white amorphous powder, bitter and acrid to the taste. It acts as a powerful errhine, causing violent sneezing. Insoluble in water, it is readily dissolved by alcohol, ether, and chloroform. When gently heated on a plate with strong sulphuric acid, it first turns yellow, then crimson. Veratrine is entirely dissipated by heat. ”

“ But it remains an important consideration that this crystallized constituent ... is built on the chemical type of the alkaloid, a class of bodies which nature forms in plants, but not in food-plants—bodies that include narcotics, stimulants, hypnotics, deliriants, poisons, tonics; some of them affecting the whole nervous system, one to excite and another to depress; and others influencing only parts of the nervous system, for special functions of the body. ”

“ One day the professor was lecturing on poisons, and he showed his students some alkaloid, as he called it, which he had extracted from some South American arrow poison, and which was so powerful that the least grain meant instant death. I spotted the bottle in which this preparation was kept, and when they were all gone, I helped myself to a little of it. I was a fairly good dispenser, so I worked this alkaloid into small, soluble pills, and each pill I put in a box with a similar pill made without the poison. ”

“ The bruised, but unshelled, seeds are digested in dilute sulphuric acid, the filtered liquor precipitated with carbonate of potassa, and the precipitate digested in alcohol as before.
3. (Parrish.) An alcoholic extract of the seeds is treated with dilute sulphuric acid, precipitated with an alkali, again dissolved in dilute sulphuric acid; the colouring matter precipitated by a few drops of nitric acid, the alkaloid by potassa. The alkaloid is then dissolved in absolute alcohol, and the solution thus formed is evaporated; one pound yields about one drachm. ”

“ If it contains any poison we may assume that it will be some alkaloid, though I will test for arsenic too. But a man of Weiss's type would almost certainly use an alkaloid, on account of its smaller bulk and more ready solubility. You ought not to have carried this loose in your pocket. For legal purposes that would seriously interfere with its value as evidence. Bodies that are suspected of containing poison should be carefully isolated and preserved from contact with anything that might lead to doubt in the analysis. ”

“ When the ether swimming on the top is perfectly clear, then decant some of it into a capsule, and leave it in a very dry place to spontaneous evaporation.
26 When we wish to look for an alkaloid in the tissue of an organ, as the liver, heart, or lungs, we must first divide the organ into very small fragments, moisten the mass with pure strong alcohol, then express strongly, and by further treatment with alcohol exhaust the tissue of everything soluble. The liquid so obtained, is to be treated in the same way as a mixture of suspected matter and alcohol. ”

“ The flowers, bark, wood, seeds, and the root have all caused serious symptoms. The active principle is an alkaloid, to which the name of Cytisine has been given. The best source is the seeds. The seeds are powdered and extracted with alcohol containing hydrochloric acid, the alcohol distilled off, the residue treated with water and filtered through a wet filter to remove any fatty oil, the filtrate treated with lead acetate; and, after separating the precipitated colouring matter, made alkaline with caustic potash, and shaken with amyl alcohol. ”

“ If it on spontaneous evaporation leaves a small quantity of a feebly-colored yellowish residue, of a repulsive animal odor, mixed with a certain quantity of sulphate of conine, this alkaloid exists in the suspected matter under analysis. To extract the alkaloid from the solution of the acid sulphate, we add to the latter an aqueous and concentrated solution of potash or caustic soda, we agitate and exhaust the mixture with pure ether; the ether dissolves ammonia, and the alkaloid is now free. We expose the ethereal solution at the lowest possible temperature to spontaneous evaporation ”

“ The principal alkaloids which are dissolved in benzene are—strychnine, methyl and ethyl strychnine, brucine, emetine, quinine, cinchonine, atropine, hyoscyamine, physostigmine, aconitine, nepalin, the alkaloid of the Aconitum lycoctonum, aconellin, napellin, delphinine, veratrine, sabatrin, sabadilline, codeine, thebaine, and narcotine. ”

“ An inquiry of the kind is, from the analytical point of view, tedious and often difficult; for though the analytical chemist can easily and quickly identify the nature of inorganic salts in a mixture or powder, and estimate their amount, most vegetable drugs which exert any appreciable effect on the body owe their power to the presence of an alkaloid or glucoside. The active principle of opium, for instance, is morphine; that of cinchona bark, quinine; that of belladonna, atropine, and so on, and the chemist can recognise any alkaloids present in a mixture or pill. ”

“ Excessive drinking is said to lead to skin and other diseases, but per contra many medicinal virtues are ascribed to the preparation. There appears to be little doubt that the active principle in this beverage is a poison of an alkaloidal nature. It seems likely that this substance is not present as such (i.e. as a free alkaloid) in the plant, but that it exists in the form of a glucoside, and that by the process of chewing this glucoside is split up by one of the ferments in the saliva into the free alkaloid and sugar. ”

“ Whatever be the agent which has set the alkaloid free, whether it be the bicarbonate of soda or potash, or caustic soda or potash, it remains, by the evaporation of the ether, on the side of the capsule as a solid body, but more commonly a colorless milky liquid, holding solid matters in suspension. The odor of the substance is animal, disagreeable, but not pungent. ”

“ The active principle of the seeds has not been satisfactorily isolated. The symptoms suggest the action of a toxalbumin. Teilleux found a resin acid; Louis Astier a volatile alkaloid, and he explains the fact that the seeds, after being heated, are no longer poisonous by the dissipation of this alkaloid. ”

“ If opium be infused in successive portions of cold water, the water dissolves all its poisonous principles, and also a peculiar acid possessing characteristic chemical properties. These principles are separated by means of the alkalis, the alkaline carbonates, or the alkaline earths. The most important of them are morphia, the chief alkaloid of opium,—narcotine, a feeble poison, not an alkaloid,—a peculiar acid, termed meconic acid,—and a resinoid substance. ”

“ To prepare the alkaloid the dried plant is chopped up and twice exhausted with boiling alcohol of 90 per cent. The residue is squeezed out while hot, and the extract, after being allowed to settle awhile, is decanted off, and evaporated to a viscid consistency over a water bath. This is then repeatedly kneaded up with fresh quantities of lukewarm water until the washings cease to taste bitter, and to give a reddish brown coloration when treated with a strong aqueous solution of iodine. ”

“ The chemist has yet to find, if he can, a plant on the globe containing the alkaloid theine, or its chemical associate, theobromine, that has not been, by some of the races of men in some of the ages of the world, brought into use as a refreshing beverage, or adjunct to food, prized for adding cheerfulness to nourishment, and giving solace to fatigue. ”

“ Chemical Composition—The aqueous infusion of the herb exhibits a slight acid reaction, and has an intensely bitter taste, which appears due to an indifferent, non-basic principle, for the usual reagents do not indicate the presence of an alkaloid. Tannic acid on the other hand produces an abundant precipitate, a compound of itself with the bitter principle. ”

“ It is perfectly stable in all climates, and permits of the instant preparation of fresh reliable solutions possessing the characteristic hæmostatic and other properties of the supra-renal gland. Similarly, as the result of researches carried out at the Wellcome Physiological Research Laboratories, crystalline salts of a specific alkaloid, which produces the characteristic effects of ergot on the blood-pressure and the uterus, have been obtained in a state of chemical purity. ”

“ The medicine was a clear red liquid, and analysis showed it to contain in 100 fluid parts, 21·3 fluid parts of alcohol, 1·8 parts of glycerine, and 4 parts of solid substance; this solid substance contained about 1 part of a tannin and 0·2 part of ash, the remainder being extractive. No alkaloid was present and no other active substance could be detected. The solid substance agreed in all respects with the solids of decoction of krameria, or a mixture of this decoction with a little tincture of kino. ”

“ Since physiological tests are, in many cases, much more sensitive than chemical tests, they have often been used for the identification of traces of poison isolated from a body. Thus a small quantity of a particular alkaloid will produce certain characteristic physiological results when injected into the circulatory system of a small animal, and should precisely the same results be obtained by the injection of the unknown substance, the obvious inference to be drawn is that the two substances are identical. ”

“ This plant is mechanically a very unfit substance for food, being of a tough, fibrous, and indigestible character. It is possible that, when the animal becomes somewhat enfeebled by lack of proper nourishment, the small amount of alkaloid may have a direct poisonous action. ”

“ The active principle which produces this result is the crystalline alkaloid, the theine, [18] a compound belonging to the same class as strychnine and a number of similar vegetable poisons. These, when diluted, act medicinally—that is, produce disturbance of normal functions as the tea does, and, like theine, most of them act specially on the nervous system; when concentrated they are dreadful poisons, very small doses causing death. The volatile oil, of which tea contains about 1 per cent., probably contributes to this effect. ”

“ Most alkaloids occur in plants, but some are formed by decomposition. Most natural alkaloids contain carbon, hydrogen, nitrogen, and oxygen, but a few contain no oxygen. The nitrogen they contain imparts to them basic properties—they are organic bases—and hence they all form salts with acids. They all possess a pronounced bitter taste, and the poisonous nature of many plants, e.g. ”

“ We put into the residue a very concentrated solution of pure carbonate of potash, and treat the whole liquid with absolute alcohol. This dissolves the alkaloid, while it leaves untouched the sulphate of potash and excess of carbonate of potash. The evaporation of the alcoholic solution gives us the alkaloid in crystals. ”

“ ALKALOID, in chemistry, a term originally applied to any organic base, i.e. a nitrogenous substance which forms salts with acids; now, however, it is usual to restrict the term to bases of vegetable origin and characterized by remarkable toxicological effects. ”

“ The same term has been used, by certain plant physiologists, to designate any agency, either external or internal, which stimulates plant protoplasm to abnormal activity. It has been pointed out that there are a variety of substances, which are themselves chemically neutral, that are powerful stimulants of vital activity if used in only minute proportions, but are powerful poisons if present in larger amounts. Many of the alkaloids act in this way upon the animal organism ”

“ After a sufficient time, we draw off the ether into a test-tube; we exhaust the mixture by two or three treatments with ether, and unite all the ethereal fluids. We pour afterwards into this ether, holding the alkaloid in solution, one or two drachms of water, acidulated with a fifth part of its weight of pure sulphuric acid, agitate it for some time, leave it to settle, pour off the ether swimming on the top, and wash the acid liquid at the bottom with a new quantity of ether. ”