A system of practical medicine. By American authors. Vol. 1

by Unknown

The microscopical examination of suspected waters sometimes gives decided indication as to the nature of the impurities; and it may be that hereafter, in connection with physiological tests, it will become of even more importance than the chemical. To determine the presence of organisms in a sample of water the best method known at present is to kill and coagulate them by means of osmic acid or chloride of platinum, and allow them to subside. This method is of course inapplicable if it be desired to use them for either culture- or inoculation-tests.

Chemists have no uniform system of reporting the results of their analyses, some using grains per gallon, U.S. or Imperial as may be, and others parts per hundred thousand or per million of the water. It is therefore difficult to appreciate the value of the figures as given by them. The following, in parts per 100,000, will enable the practitioner to form a general estimate of the character of analytical reports; but the opinion in individual cases is so modified by the coincident amounts of chlorine, ammonia, nitrous and nitric acids, that the experienced sanitarian only is qualified to put on the results an estimate which shall be in accordance with our present knowledge of such matter:

Upland Surface-Waters.
	Allowable.	Doubtful.	Impure.
Total organic elements	to .4	.4 to .6	Over .6
Oxygen required	to .3	.3 to .4	Over .4
Albuminoid ammonia	to .015	.015 to .025	Over .025
All Other Waters.
Total organic elements	to .2	.2 to .4	Over .4
Oxygen required	to .15	.15 to .2	Over .2
Albuminoid ammonia	to .010	.010 to .015	Over .015

In connection with impure water should be mentioned impure ice. Ice is purer than the water from which it forms, but if cut on a foul pond it will itself be foul, and the vitality of some microscopic organisms is not destroyed by their being frozen, as is shown by the fact that samples from the centre of blocks of ice will inoculate sterilized infusions with the germs of putrefaction, precisely as the water of which the ice is composed would have done before it was frozen. Disease has been traced to impure ice, and it may be that it is more frequently due to this cause than has heretofore been supposed; at all events, it is well to bear the possibility in mind.

The subject of impure water will be further considered in speaking of habitations.

IV. CLIMATE.—The literature of the effects of different climates upon the human body is very extensive, following the general rule that the less positive or precise knowledge there is upon a given subject the more will be written about it. Of all animals, man seems to adapt himself most readily to the extremes of climate; and, although it is commonly supposed that a tropical climate is injurious to those coming from cooler regions, yet it has been found that where he takes the same precautions to ensure cleanliness, pure water and air, and proper food, the European does not have a higher rate of mortality in Algeria or in the East or West Indies than he does at home, if the effects of cholera and yellow fever be excepted.

Dr. Parkes defines the effect of climate upon the human body to be "the sum of the influences which are connected with the solar agencies, the soil, the air, or the water of a place;" in other words, he makes it nearly equivalent to the locality or the environment. By "climate" we understand, commonly, the sum of meteorological influences, the most important of which, as regards health, are temperature, humidity, and wind. The effects of temperature in producing disease are often confounded with the effects of change of temperature, which last is perhaps the more important of the two, and should be specially borne in mind in advising climato-therapy for chronic or wasting diseases.

The influence of climate in causing disease, although well known for over two thousand years, has not led to much effort to avoid or prevent effects which are accepted as inevitable by the great majority. It is true that in the effort to secure physical comfort by houses, clothing, artificial heat, and the like, much hygienic work has been done, and the steadily increasing tendency on the part of all who can afford it to seek rest and comfort at the seaside or in the mountains during hot weather is no doubt due, in part, to the fact that experience has shown that the money expended in thus securing health and strength is a good investment. It is unfortunate that "health resorts," so called, do not always prove to be such: they become fashionable, overcrowded; the arrangements for the disposal of excreta are cheap makeshifts, leading to soil- and water-pollution, until finally an epidemic of diarrhoea or typhoid fever occurs, with the usual results.

The consideration of climate as a therapeutic agent belongs with the articles relating to the several diseases to which it is applicable. The great desideratum wherewith to place this subject upon a scientific and practical basis is a system of reliable returns of the deaths, and if possible of certain diseases, throughout the country, and especially at those points most in vogue as health resorts.

V. HABITATIONS.—That a man's health depends very much on the character, condition, and location of his dwelling-place is now so generally admitted that in many cases where a physician is called in he will be asked whether he thinks the disease has been caused by any peculiarity about the house or the bedroom of the patient. And a careful examination will usually discover in one of them several evils to be remedied, although their connection with the case in hand may be very doubtful. There are very few homes properly constructed from a sanitary point of view; and, although we may not agree with Dr. Wilson, that "the modern prison is in all sanitary essentials the best existing type of what a healthy dwelling ought to be," it is nevertheless certain that the health of the inmates is much more carefully consulted in planning a penitentiary than it usually is in planning a college, a hotel, or a dwelling-house. Matters are gradually improving in this respect: the worst of the tenement-house rookeries and fever-nests in most of our large cities have been improved or abolished, and our wealthier citizens are beginning to pay some attention to their house-drainage as well as to the pattern of their mantelpieces. But the great majority of men are still careless and negligent as to the sanitary condition of their homes, and probably two physicians out of three live in houses in which numerous defects would be pointed out by a sanitary engineer—defects of which they are themselves more or less aware. The majority of people in our large cities under existing conditions cannot afford to have healthy houses, and the great causes of the excessive mortality, and brevity of life, in all such cities, are poverty and overcrowding, the latter resulting from the former. The problem as to the best mode of improving the sanitary condition of the tenement-house population does not, however, come before the practising physician for special consideration, and need not be considered here. Nor is the physician liable to be consulted with regard to the sufficiency, from a sanitary point of view, of the plan of a house yet to be built, although he will occasionally be asked as to the healthfulness of a proposed site. The questions which he will be asked are such as the following: "Is the cause of this particular case of disease in the house, or connected with it? and if so, what is it?"—"Do you think this is a healthy house?"—"Is the location a healthy one?"—"Is it necessary that I should give up this house to preserve the lives and health of my children?" While it is, of course, often impossible to answer with precision such questions as these, an answer of some kind must be given; and this should not be a mere random guess, but based on a deliberate estimate of the probabilities in the case. The healthfulness of a house is to be judged of, in part, from its history, if it be possible to obtain any; in part, from such facts as can be discovered by a careful examination of the premises and vicinity. The sanitary history of a house is the history of the diseases and deaths which have occurred in it, together with a set of plans showing the precise location and character of the house-drainage and of its fresh-air supply. Such a record is in most cases, unfortunately, not attainable, although to a person proposing to buy or rent a house it would often be quite as important as a record of title. In a well-organized health-office it should be possible to ascertain the number and causes of the deaths which have occurred in any given house or square in the city, and also the character and location of its drainage and sewer connections. Such records are especially valuable in an investigation of an outbreak of disease in a community.