Improved ventilation is by no means the only sanitary good that parks yield to a city wise enough to possess them. A fraction, and only a small fraction, of our population, are able to leave the city during the hot months of the year, for the country. When these favored ones reach Nahant, Swampscott, or Newport, or some modest farmhouse, or comfortable dwelling by the side of the many railroads that lead from the foulness of the city to the purity of the country, or of the mountains, how gladly and enthusiastically they speak of their escape from heat, discomfort, and disease, to coolness, comfort, and health! But the mass of the community,--the artisans and work-people, whose necessities compel them to remain within the limits of the city,--their families, children, sick ones and all, have at present no such escape from close and impure air. The carrying of little children who are pinched by cholera-infantum, or spotted by scarlet-fever, or of those who are paralyzed by diphtheria, or distorted by scrofula, or emaciated by consumption, for a few hours a day into the pure air and bright sunlight of an open square, has saved many a life. Many a needless death has occurred, because the city afforded no such opportunity for escape. A few hours' exposure of a child on a mother's lap, or in a basket or carriage, to the freshness of a park, will produce a sleep that never follows opium, chloral, or ether, and will yield a chance for health that no drug can give. For the last few years, Philadelphia has shown a diminished death-rate. Dr. WILLIAM PEPPER, who has lately investigated the sanitary condition of that city, commenting upon the gratifying fact just stated, says, "While thus showing an average rate of mortality more favorable than that found in any other city containing over 500,000 inhabitants, Philadelphia has recently (1874) attained a degree of healthfulness almost unparalleled; namely, with a population at that time of 775,000, the number of deaths was but 14,966, giving a death-rate of only 19.3 per thousand. These very favorable results are largely due to the abundant and cheap water-supply, and to the opportunities given, even to the poorest citizens, for the enjoyment of pure country air in the great Fairmount Park, which contains 2,991 acres. The extent to which this is valued by the citizens may be inferred from the fact, that, during the year 1875, the park was visited by over eleven million persons." There is no reason why a park in Boston should not yield as good a sanitary result as one in Philadelphia.