It has been recognized that climates with a low relative humidity give relief to some patients with asthma. Inferentially this is due, at least in part, to the beneficial effect of dry air, which will extract more moisture from the bronchial tree than the air of a locality with a higher humidity. If this is true in respect to the bronchial moisture of asthma, it should also be true in respect to bronchial moisture from other sources, such as cardiac and renal. The possible significance of this factor was seen in the course of experimentation on an entirely different problem. It happened that a patient with cardiac decompensation was asked to inspire through a jar of calcium chloride for a five minute period. The patient expressed his gratitude for the procedure because he felt so much better and could breathe more easily than before. The experimenters' curiosity being aroused, a