Note 359 — PART VI.—ALKALOIDS AND POISONOUS VEGETABLE PRINCIPLES SEPARATED FOR THE MOST PART BY ALCOHOLIC SOLVENTS.

The question as to whether there is much nicotine in tobacco-smoke cannot be considered settled; but it is probable that most of the poisonous symptoms produced are referable to the pyridene bases of the general formula (CnH2n-5N). Vohl and Eulenberg (Arch. Pharmac., 2, cxlvi. p. 130) made some very careful experiments on the smoke of strong tobacco, burnt both in pipes and also in cigars. The method adopted was to draw the smoke first through potash, and then through dilute sulphuric acid. The potash absorbed prussic acid, hydric sulphide, formic, acetic, propionic, butyric, valeric, and carbolic acids; while in the acid the bases were fixed, and these were found to consist of the whole series of pyridene bases, from pyridene (C5H5N), boil. point 117°, picoline (C6H7N), boil. point 133°, lutidine (C7H9N), boil. point 154°, upwards. When smoked in pipes, the chief yield was pyridene; when in cigars, collidine (C8H11N); and in general, pipe-smoking was found to produce a greater number of volatile bases. The action of these bases has been investigated by several observers. They all have a special action on the organism, and all show an increase in physiological activity as the series is ascended. The lowest produce merely excitement from irritation of the encephalic nervous centres, and the highest, paralysis of those centres. Death proceeds from gradual failure of the respiratory movements, leading to asphyxia—(Kendrick and Dewar, Proc. Roy. Soc., xxii. 442; xxiii. 290). The most recent experimental work is that of A. Gautier; he found that tobacco smoked in a pipe produced basic compounds, a large quantity of nicotine, and a higher homologue of nicotine, C11H16N2, which pre-exists in tobacco leaves, and a base C6H9NO, which seems to be a hydrate of picoline—(Compt. Rend., t. cxv. p. 992, 993). The derivatives of the pyridene series are also active. The methiodides strongly excite the brain and paralyse the extremities. A similar but more energetic action is exerted by the ethyl and allyl derivatives; the iodyallyl derivatives are strong poisons. Methylic pyridene carboxylate is almost inactive, but the corresponding ammonium salt gives rise to symptoms resembling epilepsy—(Ramsay, Phil. Mag., v. 4, 241). One member of the pyridene series β-lutidine has been elaborately investigated by C. Greville Williams and W. H. Waters—(Proc. Roy. Soc., vol. xxxii. p. 162, 1881). They conclude that it affects the heart profoundly, causing an increase in its tonicity, but the action is almost confined to the ventricles. The auricles are but little affected, and continue to beat after the ventricles have stopped. The rate of the heart’s beat is slowed, and the inhibitory power of the vagus arrested. By its action on the nervous cells of the spinal cord, it in the first place lengthens the time of reflex action, and then arrests that function. Finally, they point out that it is antagonistic to strychnine, and may be successfully employed to arrest the action of strychnine on the spinal cord.

[360] Edin. Med. and Surg. Jour., xii., 1816.