Contractions. - Lach. Lah.

Trigonocephalus Lachesis.

Class, Reptilia; Section, Squamata; Order, OphidiA; Sub-order, Viperinj:; Fam., Crotalidae.

Characters. - Much difficulty exists in identifying the exact species referred to by Hering. Buchner mentions three species viz., Trigonocephalus Lachesis, T. atrox, and T. lanceolatus. The habitation, however (South America), and the general description agree best with the Lachesis mutus or Curucucu, while the name Lance-headed Viper would refer it to the Craspedocephalus lanceolatus or Fer-de-lance, a well-known and extremely poisonous snake of the Brazils. For every reason, therefore, it is desirable to use Hering's original preparation, with which the provings were made.

The virus of this serpent has been more carefully proved than that of any other. The specimen used by Dr. Hering in his experiments was obtained from the living snake, which was stunned with a blow; the poison was then collected on sugar by pressing the poison fang upwards against the bag; and this is, up to the present time, the only reliable source. In seeking a fresh supply it might be secured in the manner described under Cro-talus. Fortunately, it acts well in the high and highest dilutions, and hence the original supply may be considered inexhaustible. Should a fresh supply be obtained, its lowest dilutions should be tested upon some small animals, and if its subcutaneous injection did not produce distinct symptoms of poisoning, it should be rejected as untrustworthy.

Preparation. - Dilution in rectified spirit.

Reference to Horn. Proving. - Denkw. d. N. Am. Acad.

Proper forms for dispensing. - Tincture, Pilules, or Globules.