Dyspnœal

Leyden thinks it not improbable that these crystals are the direct causes of the dyspnœal seizure in bronchial asthma, his hypothesis being that they irritate the terminations of the vagus in the mucous membrane of the air‐passages, and in that way, by reflex action, give rise to spasm of the finer bronchi; the remissions would thus follow the expectoration of the crystals, and the patient would have ease till the renewed formation of crystals produced another attack.