Appletons' Popular Science Monthly, February 1899 Volume LIV, No. 4, February 1899

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February 1899, by Various

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Title: Appletons' Popular Science Monthly, February 1899

       Volume LIV, No. 4, February 1899

Author: Various

Editor: William Jay Youmans

Release Date: September 11, 2013 [EBook #43695]

Language: English

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Established by Edward L. Youmans

APPLETONS'

POPULAR SCIENCE

MONTHLY

EDITED BY

WILLIAM JAY YOUMANS

VOL. LIV

NOVEMBER, 1898, TO APRIL, 1899

NEW YORK

D. APPLETON AND COMPANY

1899

Copyright, 1899,

By D. APPLETON AND COMPANY.

Vol. LIV. Established by Edward L. Youmans.No. 4.

APPLETONS' POPULAR SCIENCE MONTHLY.

FEBRUARY, 1899.

EDITED BY WILLIAM JAY YOUMANS.

CONTENTS.

NEW YORK:

D. APPLETON AND COMPANY,

72 FIFTH AVENUE.

Single Number, 50 Cents. Yearly Subscription, $5.00.

Copyright, 1898, by

D. APPLETON AND COMPANY.

Entered at the Post Office at New York, and admitted for transmission through the mails at second-class rates.

GABRIEL DE MORTILLET.

APPLETONS' POPULAR SCIENCE MONTHLY.

FEBRUARY, 1899.

VEGETATION A REMEDY FOR THE SUMMER HEAT OF CITIES.

A PLEA FOR THE CULTIVATION OF TREES, SHRUBS, PLANTS, VINES, AND

GRASSES IN THE STREETS OF NEW YORK FOR THE IMPROVEMENT

OF THE PUBLIC HEALTH, FOR THE COMFORT OF SUMMER

RESIDENTS, AND FOR ORNAMENTATION.[1]

By STEPHEN SMITH, M.D., LL.D.

One of the most prolific sources of a high sickness and death rate in the city of New York is developed during the summer quarter. It has been estimated that from three to five thousand persons die and sixty to one hundred thousand cases of sickness occur annually in this city, from causes which are engendered during the months of June, July, August, and September. An examination of the records of the Health Department for any year reveals the important fact that certain diseases are not only more frequent during the summer quarter than at any other time, but that they are far more fatal, especially in the months of July and August, than during any other period of the year. These are the zymotic diseases, or those depending upon some form of germ life. The following table illustrates the course of mortality from those diseases in one year:

It appears that during eight months of the year, excluding June, July, August, and September, the average monthly mortality from zymotic diseases was 452. Had the same average continued during the remaining four months the total mortality from those diseases for that year would have been 4,424; but the actual mortality was 7,764, which proves that 3,340 persons were sacrificed during those four fatal months to conditions which exist in the city only at that period of the year. Still more startling is the estimate of the sickness rate caused by the unhealthful conditions created in the summer months in New York city. If we estimate that there are twenty cases of sickness for every death by a zymotic disease there were 66,800 more cases of sickness in the year above referred to than there would have been had the sickness rate been the same in the summer as in the other months of that year.

One of the saddest features of this high sickness and death rate appears when we notice the ages of those who are especially the victims of these fatal diseases. During the week ending July 9th last there were 399 deaths from diarrhœal diseases, of which number 382 were children under five years of age. The following table taken from the records of the Health Department show in a very striking manner how fatal to child life are the conditions peculiar to our summer season:

These statistics demonstrate the extreme unhealthfulness of New York during the summer, and the vast proportion of children who perish from the fatal agencies which are then brought into activity. It is a matter of great public concern to determine the nature of the unhygienic conditions on which this excessive mortality depends, and thus discover the proper remedial measures.

As high temperature is the distinguishing feature of the summer months, we very naturally conclude that excessive heat is a most important factor, if not the sole cause, of the diseases so fatal to human life at this period. A close comparison of the temperature and mortality records of any summer in this city demonstrates the direct relation of the former to the latter. For illustration, we will take the records of the Health Department during the past summer, selecting diarrhœal diseases for comparison, as they prevail and are most fatal at that season of the year. The table gives the total mortality from these diseases and the mortality from those diseases of children under five years of age. To the four months, June, July, August, and September, are added May and October, for the purpose of showing the gradual increase of the mortality from these diseases as the hot weather approaches and its decline as the hot weather abates.

Again, if we compare the temperature and mortality records for a series of days instead of months, it will be noticed that the mortality record follows the fluctuations of the heat record with as much precision as effect follows cause. The summer heat generally begins about the 20th of June and continues with varying intensity until the 15th of September. Within that period we can select many examples which strikingly illustrate the relations of temperature to mortality. For example, the first heated term of the year before us began on the 19th of June and lasted until the 26th of that month. The two records are as follows:

On the 28th of June a second heated term began, when the temperature rose to 80°, and continued above that figure until July 5th, a period of eight days. The following is the record, including the temperature in the sun:

It will be noticed that during the last heated period there was a more prolonged high temperature than during the first, and that the mortality of the second was higher for the same temperature than that of the first. These facts are in accord with the history of our summer months. The range of temperature increases as the season advances, and the rate of mortality rises, owing to the diminished resisting power to the effects of high heat on the part of the people, especially of the children, the aged, and those already enfeebled by disease.

In order to fully understand the influence of heat and its effects upon the public health, we must first notice the conditions regulating the temperature of the body in health and disease.

The temperature of animals in a state of health is not a fixed quantity, but has a limited range which depends upon internal and external conditions not incompatible with health. In man the range of temperature in health is fixed at 97.25° F. to 99.5° F. Any temperature above or below these extremes, unless explained by special circumstances not affecting the normal condition of the person, is an indication of disease. This comparatively fixed temperature in health is a remarkable feature of the living animal. When subjected to a temperature above or below the extremes here given it will still maintain its equilibrium. This fixed temperature under varying conditions of heat and cold is due to a heat-regulating power, inherent in the constitution of every animal, by which it imparts heat when the temperature of the air is high and conserves heat when the latter is low. The heat escapes from the body—1, by radiation from the surface; 2, by transmission to other bodies; 3, by evaporation; and 4, by the conversion of heat into motion. The surface of the body furnishes the principal medium for the loss of heat by the first three methods—viz., radiation, transmission, and evaporation. It is estimated that 93.07 per cent of the heat produced escapes by the processes of radiation, evaporation, conduction, and mechanical work. The remaining heat units are lost by warming inspired air and the foods and drinks taken. There are apparently other subtile influences, so-called regulators of heat, at work to preserve an equilibrium of temperature in the animal body, but they are not well known. The result of the operation of these forces is this—viz., if, by any means, the heat of the body is increased, compensative losses of heat quickly occur, and the normal temperature is soon restored; and if, on the contrary, the loss of heat is unusually increased, the compensative production of heat of the body at once follows, and the equilibrium is at once restored. The important fact to remember is this—viz., the production and loss of heat in the human organism when in health and not subjected to too violent disturbing causes are so nicely balanced that the temperature is always maintained at an average of 98.6° F., the extremes being 97.25° F. and 99.5° F. So beautifully is this balance preserved, Parkes remarks, that the stability of the animal temperature in all countries has always been a subject of marvel. If, however, anything prevents the operation of the processes of cooling—viz., radiation, evaporation, and conduction—the bodily temperature rises by the accumulation of heat, and death is the result from combustion. In experiments in ovens a man has been able to bear a temperature of 260° F. for a short period, provided the air was dry so that evaporation could be carried on rapidly. But if the air is very moist, and perspiration is impeded, the temperature of the body rises rapidly, and the person soon succumbs to the excessive heat. Another important fact is this, viz., the normal temperature of the young and of the very old is higher than the middle-aged. The infant at birth has a temperature of 99° F. to 100° F., and it maintains a temperature of 99° F. and upward for several days. The variations of temperature from other causes are much greater in children than in adults, as also the normal daily variations of temperature. About the sixtieth year the average temperature of man begins to rise, and approximates that of the infant. In the young and old the heat-regulating power is more readily exhausted, and hence continued high temperature is far more fatal to these classes.

The first noticeable fact in regard to bodily temperature in disease is that there are daily fluctuations as in health, but much more extreme. In general, the remission of temperature in disease occurs in the morning, and the exacerbation in the afternoon and evening; the minimum is reached between six and nine o'clock in the morning, and the maximum between three and six o'clock in the evening. In many diseases the minimum temperature is not below 100° F., and usually it is one or two degrees above that point, while the maximum has no definite limit and may reach the dangerous height of 107° F. It should be noticed that the highest daily temperature in disease, as in health, occurs in the afternoon, when the temperature of the air in summer is the greatest.

The conditions affecting the temperature of the body other than those due to physiological conditions are very numerous. First and most obvious is the temperature of the surrounding atmosphere. It is a well-established fact that an average temperature of the air of 54° F. is best adapted to the public health, for at that temperature the decomposition of animal and vegetable matter is slight, and normal temperature is most easily maintained. Every degree of temperature above or below that point requires a more or less effort of the heat-regulating power to maintain the proper equilibrium. Even more potent in elevating the bodily temperature is the introduction into the blood, whether by respiration or by direct injection, of putrid fluids and the gases of decomposing matters. If this injection is repeated at short intervals, death will occur with a high temperature. The air of cities contains emanations, in hot weather, from a vast number of sources of animal and vegetable decomposition, and the inhalation of air so vitiated brings in contact with the blood these deleterious products in a highly divided state which cause a fatal elevation of temperature in the young, old, and enfeebled. The same effect is produced by the air in close and heated places, as in tenement houses, workshops, schoolhouses, hospital wards, and other rooms where many persons congregate for hours. Air thus charged with poisonous gases becomes more dangerous if the temperature of the place is raised, as happens almost daily in the summer months in cities.

From the preceding facts we may conclude that, as long as the body continues in health, the heat-regulating power, which constantly tends to preserve an equilibrium of temperature, is capable of resisting the ordinary agencies that, operating externally or internally, exaggerate the heat-producing conditions, and thus destroy the individual. But if the person is suffering from a disease which weakens the heat-regulating power these deleterious agencies, which the healthy person may resist, will readily overpower the already quite exhausted heat-regulating forces, and he perishes by combustion. It is very evident that in an organism having complicated functions, like that of man, and subject to such a multitude of adverse influences, the balance between health and disease must be very nicely adjusted. Too great an elevation or too great a depression of temperature may destroy the heat-regulating power, and disease or death will be the consequence. Or this heat-regulating power may be weakened or destroyed by causes generated within the body, or received from without, and the heat-producing agencies are then under influences which may prove to be powerfully destructive forces.

It will not now be difficult to understand in what manner high temperature affects the public health of large cities. Evidently in the direct action of heat upon the human body we have the most powerful agency in the production of our great summer mortality. While sunstroke represents the maximum direct effect of solar heat upon the human subject, the large increase of deaths from wasting chronic diseases and diarrhœal affections, of children under one year of age and persons upward of seventy years of age, shows the terrible effects of the prevailing intense heat of summer upon all who are debilitated by disease or age and thereby have their heat-regulating power diminished. The fact has been established by repeated experiment that when solar or artificial heat is continually applied to the animal the temperature of its body will gradually rise until all of the compensating or heat-regulating agencies fail to preserve the equilibrium, and the temperature reaches a point at which death takes place from actual combustion. In general, a temperature of 107° F. in man would be regarded as indicating an unfavorable termination of any disease. In persons suffering from sunstroke the temperature often ranges from 106° F. to 110° F., the higher temperature appearing just before a fatal termination.

The indirect effects of heat appear in the production of poisonous gases which vitiate the air and render it more or less prejudicial to health. Decomposition of all forms of refuse animal and vegetable matter proceeds with far greater rapidity during the summer quarter than during other months of the year. Among the early results of summer heat is the damage to food. Milk retailed through the city, the sole or chief diet of thousands of hand-fed infants, undergoes such changes as to render it not only less nutritious but also hurtful to the digestive organs. The vegetables and fruits in the markets rapidly deteriorate and become unfit for food. Meats and fish quickly take on putrefactive changes which render them more or less indigestible. The effect of this increase of temperature upon the refuse and filth of the streets, courts, and alleys, upon the air in close places, in the tenement houses, and upon the tenants themselves is soon perceptible. The foul gases of decomposition fill the atmosphere of the city and render the air of close and unventilated places stifling; while languor, depression, and debility fall upon the population like a widespread epidemic. The physician now recognizes the fact that a new element has entered into the medical constitution of the season. The sickly young, the enfeebled old, those exhausted from wasting diseases, whose native energies were just sufficient to maintain their tenure of life, are the first to succumb to this pressure upon their vital resources. Diarrhœal diseases of every form next appear and assume a fatal intensity, and finally the occurrence of sunstroke (or heat-stroke) determines the maximum effects of heat upon the public health. The sickness records of dispensaries and the mortality records of the Health Department show that a new and most destructive force is now operating, not only in the diseases above mentioned, but in nearly all of the diseases of the period. Fevers, inflammatory diseases, and others of a similar nature run a more rapid course, and are far less amenable to treatment. This is due, in the opinion of eminent medical authority, to the addition of the heat of the air to the heat of the body. Indeed, the only safety is in flight from the city to the country and to cool localities, as the seashore or the mountains. The immediate improvement of those suffering from affections of the city when transferred to the country is often marvelous, and shows conclusively how fatal is the element of heat in its direct and indirect effects upon the residents of the city.

Let us next consider the causes of high temperature in the city of New York. It is a well-established fact that the temperature of large and densely populated towns is far higher than the surrounding country. This is due to a variety of causes, the chief of which are the absence of vegetation; the drainage and hence the dryness of the soil; the covering of the earth with stone, bricks, and mortar; the aggregation of population to surface area; the massing together of buildings; and the artificial heat of workshops and manufactories. The difference between the mean temperature of the city at Cooper Institute and at the Arsenal, Central Park, for a single month, illustrates this fact. Another striking difference between the temperature of these two points of observation is that the range is much greater at Central Park than at Cooper Institute, the temperature