Turbidity

“ Fluid in contact with Ordinary Air and its Particles; Neck of Flask Sealed after the Fluid had become Cold. No. IV.—Urine remained quite bright and clear during the fifteen days in which it was kept under observation in the water-bath.48
No. V.—Hay Infusion after forty-four hours showed a well-marked turbidity. In sixty-eight hours there was an increase in the amount of turbidity, and also some sediment. During the next forty-eight hours turbidity and sediment gradually increased, whilst the colour of the fluid (originally that of port wine) became several shades lighter. ”

“ For river-waters the ratios are always larger. With very sluggish rivers the ratio is only a little larger than for settled waters. For average river-waters the ratio is considerably higher, and increases with the turbidity, and for very rapid rivers and torrents the ratio is much wider, as the suspended matters consist largely of particles which are heavy but do not increase very much the turbidity. ”

“ He found (as I have also frequently found) that when fluids had been subjected to the influence of high temperatures, and had subsequently remained sterile in closed flasks, they might be freely exposed to the air for one or two weeks, or more, without becoming turbid—although at any time a general turbidity could be speedily induced, by introducing a few living Bacteria into the fluid.
84 ‘On the Direct Correlation of Mechanical and Chemical Forces.’—Proceedings of the Royal Society, vol. xii. pp. 539 and 546.
85 ‘Traité de Physiologie.’ Translated by Jourdan. 1837. t. i., p. 18. ”

“ If we also visit the spot at a time when the river is swollen by heavy rains or melting snows, the presence of this organic matter will be masked by the turbidity of the water; we shall learn that only in the freshet seasons does the water attain sufficient velocity to carry any visible load of sand and clay. ”

“ Only in the case of excessive quantities of mud, where, for other reasons, sand filters can hardly be considered applicable, is there a moderate reduction in bacterial efficiency. As mentioned above, particles constituting turbidity are often much smaller than the bacteria, and in addition, the bacteria probably have an adhesive power far in excess of that of the clay particles. ”

“ The atmosphere is the source of water supply. The vapor of water therein is condensed and falls in the form of rain, snow, or dew. Rain, obviously, must carry down with it the impurities in the atmosphere—gases, dust, and bacteria. It must cause deeper deposition of organic matter as it passes into the soil. It becomes either surface water augmenting the streams, or ground water supplying wells and subterranean reservoirs. Impure water carries the germs of many diseases, as typhoid fever, diphtheria, diarrhoea, dysentery, malaria, cholera, probably yellow fever, etc. ”

“ Raindrops carry the germs to the ground. Hence the advantage of a thunder plout in a sanitary way. A cubic foot of rain has been found to contain 5500 organic dust-germs, besides 7,000,000,000 of inorganic dust-particles. In a dirty town the rain will bring down in a year, upon a square foot of surface, no less than 3,000,000 of bacteria, many of them being disease-bearing and death-bearing. No wonder, then, that scientific men are using every endeavour to protect the human frame, as well as the frame of the lower animals, from the baneful inroads of these floating nuclei of disease and death. ”

“ When the east winds blow along the Atlantic coast for a little while, they bring us air saturated with moisture from the Gulf Stream, and we complain of the sultry, oppressive, heavy atmosphere; the invalid grows worse, and the well man feels ill, because, when he takes this atmosphere into his lungs, it is already so charged with moisture that it cannot take up and carry off that which encumbers his lungs, and which nature has caused his blood to bring and leave there, that respiration may take up and carry off. ”

“ We hurried on—men and animals together rushing into the stream, the men lapping the water up like dogs, and dipping their whole bodies in without even stopping to pull off any of their clothes. It is a wonder the sudden change from heat to cold did not kill some of us; but the fact is, that our pores were so completely closed up with dust that the bath, by removing the dirt, allowed the perspiration to escape and saved us from fever. ”

“ If we add moisture to a sunless spot, we have the ideal environment for germs to breed and flourish in. There is always moisture or humidity in the air if the altitude is low, and if it is near the ocean, or any large body of water, the moisture is relatively greater. For this reason we send patients with pulmonary disease to the mountains, where the altitude is much higher, where there is no moisture, and consequently where there are practically no germs. ”

“ It seems probable that towards the end of a drought the very air, uncleansed by shower and storm, becomes charged with disease germs. As to water pollutions, sometimes the disease is at its fiercest before a heavy fall of rain, to disappear almost magically afterwards. At other times the rain seems to intensify the epidemic. The dry air of the interior, however hot, has always been thought to be antagonistic to the disease. ”

“ The great humidity produced by heavy rains and inundations, the exuberant vegetation caused by fervid heat in rich moist soil, and the prodigious amount of decaying vegetable matter annually exposed after the inundations to the rays of a torrid sun, with a flat surface often covered by forest through which the winds can not pass, all combine to render the climate far from salubrious for any portion of the human family. But the fever, thus caused and rendered virulent, is almost the only disease prevalent in it. There is no consumption or scrofula, and but little insanity. ”

“ In the hot season, heat from without combines with heat from within, and produces an unhealthful degree of heat in the body, and causes disease of the fire-class. In the rainy season too much water is absorbed into the system, filling intensely the natural vacuum in the upper part of the head, and produces disease of the water-class. The earth produces disease through her mists and vapors. ”

“ Swamps and stagnant pools, moisture-laden air, and a hot climate have been universally considered to be the cause of the fever, and the transmission of the disease has been supposed to be due to the passage through the moist air of the germs of the disease, although the exact form and behavior of these germs was unknown. ”

“ Neither moisture nor smoke give that yellowish look here; it is the sand which the wind collects as it blows across the desert in its northern course. As the wind increases, so the temperature rises, and the extreme dryness of the air causes those unpleasant sensations felt with the first symptoms of fever. ”

“ Cultivation and drainage are now fully understood to be the basis by which a healthy condition of air is to be obtained, next to that, cleanliness and ventilation; if either be neglected a sickly, mouldy, and unwholesome contamination of atmosphere ensues; the odour of a bog is proverbially mouldy, and so is that of an ill-ventilated house or cellar; dryness, or the fresh pleasant scent of clean water, are the antagonists of these; the aromatic odours of vegetation are opponents of putrefaction, and consequently of the development of the lower forms of life. ”

“ Notwithstanding our imperfect acquaintance with the manner in which water is suspended in the atmosphere, it is well known that the human body is greatly influenced by the aqueous vapour in such a state of suspension, and that the sources of poisonous emanations are active in proportion to the grade of atmospheric humidity and its temperature. An atmosphere surcharged with humidity not only prevents the cuticular discharge necessary to a healthy state, but sensibly diminishes the watery exhalations from the lungs, thereby inducing various morbid effects on the system. ”

“ As, by the greater pressure and humidity of the atmosphere, the pores of the skin are so affected that they become unable to perform their office of exhalation, with the same facility as in winter and summer, it follows that perspirable matter, or at least, its grosser particles, will in autumn be liable to remain on the surface, in a state inclining to putrefaction, and to be re-absorbed, to the great detriment of the human or animal body. ”

“ It also fills the air with noxious vapours during the short bursts of sunshine perpendicularly rained down, and breeds a hateful brood of what the Portuguese call immundicies--a foul 'insect-youth.' Only the oldest residents prefer the wet to the dry months. The Rains end in the sickliest season of the year, when the sun, now getting the upper hand, sucks the miasmatic vapours from the soil and distributes them to mankind in the shape of ague and fever, dysentery, and a host of diseases. ”

“ When compared with the rainfall map of the country, the disease seems to prevail most where there is least rain. So in Ireland, where the rainfall is very heavy, fatality from calculus is rare. Exposure to a dry atmosphere means, of course, more loss of fluids to the body than immersion in a moist atmosphere; and it has been proved experimentally that immersion in water of a lower temperature than the body of itself lessens the acidity of the urine. ”

“ And this relation of cause and effect, manifest in individuals, is one which we may suspect holds in races—other things being equal. In temperate regions, differences of constitutional activity due to differences of atmospheric humidity, are less traceable than in torrid regions, the reason being, that the inhabitants are subject to a tolerably rapid escape of water from their surfaces, since the air, though well charged with water, will take up more when its temperature, previously low, is raised by contact with the body. ”

“ While admitting that there may be cases where the effects of certain rays of the sun are responsible for clinical manifestations varying from death of striking suddenness to vague complaints of irritability, headache and defective memory, yet the generally accepted views are that high temperature, high relative humidity and lack of evaporation from the skin, whether from excessive humidity or from lack of circulation of the surrounding air, can and do produce at one time heat stroke and at another heat prostration. ”

“ In warm moist air strength is lost and there is a distinct tendency to intestinal troubles. In moist cold air perspiration is checked, and rheumatic and joint affections are very common. The main differences between mountain air and that of the plains depend on the former being more rarefied, colder, of a lower absolute humidity, and offering less resistance to the sun’s rays. ”

“ It is standing water which purifies itself, if anything, for in stagnation there is much more chance for the disease germs to die out. Better than either a pond or stream, unless you can carry out a rather careful exploration of their surroundings, is ground water from a well or spring ”

“ A number of reports, American and foreign, seem to concur in fixing the origin of the disease in some condition of the ground or water, and indicate that it may be produced by foul water, by foul air, or by emanations from the earth, occurring most frequently in the autumn and during seasons of drought. ”

“ We relate this little incident to point out the almost certain consequence of getting wet in this climate, and allowing the clothes to dry on the person. Even if we walk in the mornings when the dew is on the grass, and only get our feet and legs wet, a very uneasy feeling and partial fever with pains in the limbs ensue, and continue till the march onwards bathes them in perspiration. ”

“ Modern hygiene has observed that certain variations in the moisture of the soil have a great influence on the origin and spread of certain epidemic diseases, as for instance cholera and typhoid fever—that these diseases do not become epidemic when the moisture in the soil is not above or below a certain level, and has remained so for a time. ”

“ During the night plants only give off carbonic acid.
2. The Fall of Rain clears the atmosphere of any solid particles contained in it, the impurities being transferred to rain-water which generally contains an appreciable amount of ammonia as well as other impurities. Rain not only washes and purifies the air, but by washing the ground, diminishes dust, and prevents its escape into the air. It is the great natural scavenger.
3. Ventilation—that is, the interchange of pure and impure air, is constantly being effected. ”

“ If the entire surface of the body is involved, the application must be as extensive as necessary to affect the whole. In general fevers, the admirable adaptation of water to this end is well exhibited. When the temperature of the body rises above 100°, or even above 98°, a cooling bath should be resorted to. It may consist of a simple sponging with water, scarcely below the bodily temperature, an affusion with tepid water, a full bath of a tepid, temperate, or cold temperature, or some other form of cooling application according to the degree of cooling effect desired. ”

“ Animals that have been working in cold rains should be dried and cooled out and not left to dry by evaporation. When the temperature of the weather is at the extreme, either of heat or cold, diseases of the organs of respiration are most frequent. ”

“ But the best climate for an invalid depends on the particular weakness from which he may suffer. Pulmonary tuberculosis stands first in the importance of the effects of climate. The continuous supply of pure fresh air is the main desideratum, a cool climate being greatly superior to a tropical one. Exposure to strong winds is harmful, since it increases the tendency to cough and thus leads to loss of body temperature, which is in its turn made up at the expense of increased metabolism. ”