The Summer is the period during which experience tells us the heaviest strain is brought to bear upon the human system. In our latitude the temperature varies, perhaps, more than in any other part of the world. Taking this year's record as an instance, we find a range of temperature from January to August of something like 115 degrees of the thermometer.

For two or three days in January last the mercury ranged as low as 15 degrees below zero; it has already reached 108 degrees above, and a great many people who were subjected to the minimum exist during the Summer hot spells at a figure considerably above that recorded in the thermometrical observations as published. This range of temperature is considerably more than half that required to raise water from the freezing to the boiling point. A black of granite exposed to such alternations for a period covering the life of man, would, if not artificially protected, by the laws of contraction and expansion, begin to crumble away. Indeed where the process is carried on for centuries, the very mountains are split and decay and sweep humanity before them when the static force that held them is dissolved or rent by a superior power.

But for the vital principle which adjusts the human frame in various ways to its surroundings, meeting every new tax upon it by a constant readiness of resources, rebuilding perpetually what the elements have ravaged and accommodating the body to its ever changing conditions mankind would speedily be torn out of existence. In our climate these changes are not marked by any gradual merging of one condition into another. Intense cold is followed by great heat; with steps like those of a drunken giant our patch of land stalks from Midwinter to Midsummer, now staggering fatally forward, now slipping backward in its uneven progress. This year it has moved slowly for a time; now it has plunged into the torrid heats of a tropical Summer. The system fails, perhaps, to meet these capricious movements. The natural processes are interrupted. The perspiration which flows to cool a body exposed to a temperature higher than its own is suddenly checked, and all the organs from the liver onward are thrown into confusion. Among the morbific effects of such a rout come bowel troubles, which, in a few hours, reduce the stoutest to the helplessness of an infant. Dysentery and kindred disorders are the direct gifts of an American Summer. Even where they do not appear there is an inevitable predisposition to them. The fetid air of the tenement striking into the weakened lungs of the child and leaving its poison in the system carries off the babies at the rate of more than 200 a week in Brooklyn.

It is customary with such people as can afford to leave the city in the middle of the Summer to go to some watering place, a quiet and healthful retreat among the mountains or in a quiet country village. Long Island offers unusual attractions and facilities for such visitors and it is not surprising that for many years the healthful shores of the South Side have been lined with city residents during the Summer months. As a rule they can scarcely do better, for all the conditions in general favor health. Nevertheless, numbers of people, not only on Long Island, but in other country places, have been more or less surprised to find themselves affected by the mysterious choleric symptoms of Summer. Where these are not marked they are generally attributed to a "change of water," and the patient simply waits until his system has adapted itself to the new conditions.

According to a very elaborate investigation made by the officers of the State Board of Health into the outbreak of dysentery last Summer, at Southampton and Babylon, which came with all the suddenness and swiftness of an epidemic, the water was undoubtedly responsible, just as it usually is, but not quite in the manner supposed by the country boarder. Chemical analysis of the well water used in the houses whose occupants were attacked, revealed the extremely unpleasant fact that it was utterly unfit to drink, containing as it did a large admixture of sewage. The explanation was very simple. Long Island seems to lie upon a large subterranean lake, which comes to the surface at intervals, forming the numerous ponds which constitute its principal phenomenon. From this lake water is obtained at a varying depth.

The soil is light and sandy, and readily permits the passage of fluid through it. An examination of thirteen premises in which the disorder broke out in Southampton, a place noted for its salubrity, disclosed the interesting fact that the cellars and cesspools of the houses were in more or less close proximity to the wells, were generally on higher ground and that the natural course of the fluid filth through the soil was directly toward the drinking water reservoirs. In several instances it was found that the wells and cellars had unbroken contact and that the inmates of the houses were actually dipping into a sewer for what should have been a source of health as well as of refreshment. Under such circumstances the appearance of dysentery was a blessing; the only wonder was that a most serious outbreak of typhus fever did not result. Of course the cellars were promptly filled as soon as this state of things was discovered and the outhouses were moved. Southampton is again among the most healthful resorts on Long Island.

The conditions observed there, however, will, doubtless be found on examination to be more or less prevalent not only in other places on Long Island but in all villages to which city people resort. The Summer boarding house is apt to be quickly run up and its attachments located without due consideration of the important fact of subterranean communication. Our readers would do well before taking board to inquire into the nature of the soil and the relative position of the wells and outhouses before exposing themselves, and especially their children, to the danger of poison by sewage. This poison may not be taken into the system in sufficiently large quantities to immediately manifest itself, but it may remain for months slowly developing, and show itself in the Fall and Winter in malarial symptoms, in scarlet fever, diphtheria and typhoid diseases, all of which can be directly traced to putrescence in wells.

It is by no means improbable that the prevalence of Summer complaint in Brooklyn, and especially among children, may be traced to a similar cause, namely, pollution of wells. In many of our most densely populated neighborhoods are to be found the old wooden pumps by which water is raised from wells. The soil in these neighborhoods is unquestionably full of refuse from leaky drain pipes, carelessly emptied slops, from decaying matter whose distillations have been washed downward by the rainfall of many years and which are carried into those wells.

Some twenty years ago the continued appearance of typhoid disease in London led to the appointment of a parliamentary committee to inquire into the causes. Full analyses were made of the pump water of the city and with scarcely a dozen exceptions within the corporate limits of the metropolis was a well to be found that was not tainted with animal matter in some form of putrescence. The health of London required the discontinuance of these sewers for drinking purposes. A great deal of well water in Brooklyn is drunk by children. Heated with play, they are in the habit of quenching their thirst at the pump these hot Summer days. It is essential that the water, at all events in the thickly populated neighborhoods, should be carefully examined, and if found to contain poison germs its use should be prohibited.