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 *tical returns, showing the number of days each person was annually off work from sickness, the ages at which superannuated allowances were granted, the period of death, and the prevalent diseases.

CHAPTER XXXIV.

OF POISONS OF THE UMBELLIFEROUS ORDER OR PLANTS.

The Natural Order Umbelliferæ contains a variety of plants, to which narcotico-acrid properties have been at different times ascribed. But these properties have been satisfactorily traced in the instance of four species only, the Conium maculatum, Œnanthe crocata, Cicuta virosa, and Æthusa cynapium. It is supposed that others may be poisonous. But the facts on the subject are equivocal; for the several species of the family are very apt to be confounded with one another, and there is reason to think that other species have repeatedly been mistaken for one of the four already mentioned. The symptoms caused by the umbelliferous narcotics comprehend chiefly coma, convulsions, paralysis, and delirium. But the knowledge possessed on this head is rather vague, and the phenomena are not unfrequently complex and difficult to observe with accuracy; so that their nature has been sometimes misunderstood. The irritant properties of the poisons of this tribe of narcotico-acrids are seldom well defined. Of Poisoning with Hemlock.

The first to be mentioned is the common hemlock, or Conium maculatum, one of the most abundantly diffused of umbelliferous vegetables. It is distinguished from all those which it resembles by its tall, smooth, spotted stem,—its smooth leaves,—the rugged edge of the five ribs of its fruit,—its singular mousy odour,—and the very peculiar odour of conia, emitted when the pulp or juice of the leaves is mixed with caustic potash. The only other umbelliferous native which has a spotted stem, the Myrrhis temulenta, is easily distinguished from hemlock by the whole plant being very hairy.

Cases of poisoning with hemlock are not infrequent on the continent, the root having been mistaken for fennel, asparagus, parsley, but particularly parsnep. It is generally believed to have furnished the poison which was used in ancient times, and especially among the Greeks, for despatching criminals; but we have not any precise information on the subject.

A peculiar alkaloid was indicated in hemlock not long ago by Brandes, half a grain of which killed a rabbit with symptoms like those of tetanus. Other chemists were unable to obtain his results.