Local anæsthesia / by Arthur Schlesinger ; translated by F.S. Arnold.

  • Schlesinger, Arthur.
Date:
1914
Catalogue details

Licence: In copyright

Credit: Local anæsthesia / by Arthur Schlesinger ; translated by F.S. Arnold. Source: Wellcome Collection.

    30/232 (page 18)
    LOCAL ANAESTHETICS Though, as we have stated above, cocain itself is no longer widely used, it, nevertheless, as the first of modern local anaesthetics, and the one from which nearly all those in common use to-day may be said to' have been derived, deserves special and prior mention and consideration. Cocain, an alkaloid obtained from the leaves of the coca-plant, was first isolated by Niemann and Lessen in Wohler’s laboratory. Later it was pro- duced synthetically. Commercial hydrochlorate of cocain of the present day is a white powder freely soluble in water and alcohol. It is odourless, but has a bitter taste. The nature of the local action of cocain has been a subject of prolonged controversy. It was formerly held that it acted by virtue of its power to produce anaemia, as it is known to cause contraction of the smaller blood- vessels and capillaries. This anaemia certainly plays a part in cocain anaesthesia, which we shall consider later ; the actual anaesthetic effect, how- ever, depends on a purely chemical action, on an J 8