AUTUMN is notoriously a dangerous season from the point of view of health. Cold evenings, days that start as summer and end as winter, and November fogs combine to undermine the constitutions of all but the strongest, and make one start the winter with a cold that one never properly shakes off. Dr. Saleeby's talk tonight will be devoted to giving some general principles and some particular hints to those who are anxious to preserve their health unimpaired throughout these gloomy months.