Not officinal. - The bark of Aspidosperma Quebracho, imported from the Argentine Republic.

Characters. - In large pieces, about three-quarters of an inch thick, greyish-brown outside, yellowish inside, intensely bitter.

Composition. - It contains six alkaloids, the most important of which are quebrachine, aspidosamine, and aspidospermine; others are called quebrachamine, hypoquebrachin, aspidosper-matin. There is also a peculiar kind of tannic acid.

Preparations.

Tinctura Quebracho (1 in 5 of proof spirit)..........................................

1/2-l fl. dr.

Aspidospermine.....................................................................................

0.5-1 gm.

Quebrachine ..........................................................................................

Action. - Quebrachine is the most active of the alkaloids; aspidosamine ranks second, and aspidospermine third. These three have a similar action. Respiration is first affected, in warm-blooded animals the fulness and frequency of breathing being increased, and finally respiration is paralysed. In frogs respiratory paralysis, from an affection of the respiratory centre, rapidly follows the introduction of the poison. The central nervous system is paralysed, the brain being first affected so that there is at first a loss of voluntary movement, with increase of reflex excitability; finally the spinal cord also is paralysed. Voluntary muscle is paralysed by the local action of all these alkaloids, and aspidosamine and hypoquebrachin paralyse also the motor nerve endings.1 The heart is paralysed in coldblooded animals after the respiration; it is at first slowed, and the peripheral ends of the vagus are paralysed ; in warm-blooded animals the cardiac paralysis is said to be primary.2

Uses. - It has been used to lessen dyspnoea in asthma, emphysema, and phthisis.

1 E. Harnack and K. Hofmann, Zeits.f. klin. Med., Bd. viii. Hft. 6, 1884.

2 G. Gutmann, Archiv f. exper. Patholog. u. Pharmakol., xiv. p. 451.