An artificial chest wall was constructed which was large enough to hold a whole excised human lung. this device was connected to a modified Harvard Respirator which was capable of being programmed to produce any reasonable respiration rate. Freshly excised lungs free of any disease and cuts wer placed in the chest wall and challenged with both monodisperse and polydisperse aerosol particles. Total lung deposition was measured and extremely good agreement was obtained with a specially-developed theorectical model.