In these studies I limited myself strictly to bronchial asthma, or the so-called idiopathic or essential bronchial asthma. Cases of asthma due to sensitization to animal proteins, excretions and secretions were excluded. Likewise, individuals sensitive to pollens, plant proteins and foodstuffs were eliminated. Most of the cases studied came from Dr. H. B. Wilmer's Asthma Clinic at the Presbyterian Hospital.
All these patients had chronic infections either of the bronchi or sinuses, or both, with varying amounts of mucopurulent secretions. Many of them were more comfortable and some were entirely free from asthma during the summer months, when their respiratory infections had subsided temporarily. With the onset of cold weather and the prevalence of upper respiratory infections, the asthmatic condition invariably became aggravated. This was always coincident with an increase in mucopurulent bronchial or nasal secretions. The relationship between the asthmatic attacks and the respiratory infections was unmistakable. Rosneau and