The second condition alluded to is characterized by a persistent, harsh, irritating cough, with little or no expectoration, indicating a sensitive and congested condition of the mucous membrane with diminished secretion. Such cases may generally be much relieved by adding to the antiseptic and anodyne mixture just given some one of the oleo-resin or balsamic preparations, of which perhaps none are more efficient than that which is known in the shops as oil of Scotch pine. Four cubic centimeters (fluidrachm j) of this may be added directly to the quantity of the other ingredients already given, and then used in the same manner. The combination thus used appears to allay the morbid sensitiveness and speedily establishes a better secretory action. There is another important class of cases met with most frequently in persons of both sexes between twelve and twenty years of age. They present a narrow, imperfectly-developed chest, with so sensitive a condition of the bronchial membrane that every trifling exposure to cold and damp air renews the vascular hyperæmia and cough, until both become permanent and the morbid process extends into the connective tissue of the pulmonary lobules, {183} establishing what some call interstitial pneumonia and others fibroid phthisis. In the earlier stage of all this class of cases the systematic daily practice of full, deep inhalations of pure atmospheric air, coupled with a judicious exercise of the muscles of the chest and arms, will do more to remove all symptoms of bronchial disease and preserve the general health of the patient than all the medicines that have been hitherto devised. There is much evidence in favor of using compressed air for inhalation in these and some other cases of bronchial inflammation. The late F. H. Davis of this city, who during his brief professional career gave much attention to the treatment of diseases of the respiratory organs, and had good opportunities for clinical observation, says, when speaking of the same class of young subjects, that "the inhalation of compressed air for from five to ten minutes once or twice a day produced marked and rapid improvement in all the cases. The size of the chest on full inspiration was increased from one-half inch to one inch in the first month, and a habit of fuller, deeper breathing and a more erect carriage was established."[8] But he adds, with proper emphasis, that the inhalations to be permanently curative must be continued faithfully for many months, and be accompanied by a judicious regulation of all the habits of life. [Footnote 8: See paper read before the Chicago Society of Physicians and Surgeons, April, 1877, on "The Respiration of Compressed and Rarefied Air in Pulmonary Diseases."]