In our experiments, alcohol in large and repeated dosage caused marked morphologic changes in the brain-cells which went as far even as the destruction of some of the cells (Fig. 39). Ether, on the other hand, even after five hours of administration, produced no observable destructive changes in the brain-cells. The effect of iodoform was peculiarly interesting, as it was the only drug that produced a rise of temperature. Its observed effect upon the brain-cells was that of wide-spread destruction. Infections.--In every observation regarding the effect of pyogenic infections on dogs and on man we found that they caused definite and demonstrable lesions in certain cells of the nervous system, the most marked changes being in the cortex and the cerebellum (Fig. 40). For example, in fatal infections resulting from bowel obstruction, in peritonitis, and in osteomyelitis, the real lesion is in the brain-cells. We may, therefore, reasonably conclude that the lassitude, the diminished mental power, the excitability, irritability, restlessness, delirium, and unconsciousness which may be associated with acute infections, are due to physical changes in the brain-cells. Graves' Disease.--In Graves' disease the brain-cells show marked changes which are apparently the same as those produced by overwork, by the emotions, and by strychnin. In the postmortem examination of one advanced case it was found that a large number of brain-cells were disintegrated beyond the power of recuperation, even had the patient lived. This is undoubtedly the reason why a severe case of exophthalmic goiter sustains a permanent loss of brain power.