Sir John Floyer1in 1698 first suggested that the pathologic physiology of asthma was, basically, a contraction of the muscles in the bronchial wall. Since that time strenuous efforts have been made to demonstrate changes of a characteristic nature that would offer definite proof of this hypothesis. Physiologic facts brought out by animal experimentation seem to offer evidence, by analogy, that muscle contraction plays a part in the production of an asthmatic paroxysm. Several observers, however, notably Coca.2refuse to accept this as proved. The evidence in favor of the theory of bronchospasm is ably presented by Alexander,3who quotes many observations, beginning with those of Haller in 1756 The latter noticed that the lung drew itself together on the application of strong acid. Varnier4in 1779 reported the contraction of the finer air tubes when exposed to certain irritating fumes and liquids. The first definitely