cause they cause no discoloration. The Metropolitan Disinfectant, much used in New York for disinfection of privies, contains half a gallon of dead oil, one gallon of copperas solution (saturated), diluted with water to make three gallons.

A patented apparatus, called the Germicide, is in frequent use in New York for disinfecting water-closets. Every time the closet is used a small amount of zinc chloride is discharged into the pan or bowl, and the vapor of thymol is mingled with the atmosphere of the room.

Corpses, when infectious, should be wrapped in cloth saturated with a strong solution of zinc chloride or carbolic acid, and a pad of sawdust or fine shavings saturated with the same solution placed under the hips, to disinfect discharges.

The bodies of those who have died of small-pox should be buried in air-tight coffins (metallic) and no funeral should be allowed.

Street Gutters, etc.-Ferric or ferrous sulphate. Chloride of lime. The New York Board of Health uses a zinc and iron solution obtained as a byproduct in de-tinning scrap-tin plate. It contains about 4 per cent. of ferrous sulphate, 14 per cent. of ferrous chloride, and 9 per cent. of zinc chloride.

Utensils.-Zinc chloride (two ounces to the gallon). Mercuric chloride (one drachm to the gallon). Potassium permanganate (one ounce to the gallon). The latter salt stains clothing brown.

The Girondin Disinfectant and Platt's Chlorides are in very common use. An analysis of the former, made by Waller, shows the following constituents:

VITAL STATISTICS.

BY ROGER S. TRACY, M.D.,

Sanitary Inspector of the Board of Health, New York.

It is important to know not only the exact number, if possible, of births, marriages, and deaths in a population, as well as the number of the living, but the value of such statistics is immensely increased, if it can be learned with accuracy what are the occupations, residences, birthplaces, ages, race, etc., of the persons enumerated, as well as the meteorological conditions under which they have lived from day to day. An attempt was made in the United States in 1870 to furnish a complete census of the population upon such a comprehensive plan, but as the time allowed for its completion was only three months, the work was full of inaccuracies. The census of 1880 was conducted on a larger scale, and is expected to furnish a greater body of important facts, with more complete and useful classifications, than any such work hitherto undertaken in the world. The magnitude of the task may be inferred from the fact that, at the present time (October, 1883), more than three years after its inception, the first volume of reports is barely ready for distribution.

The first attempt at registration in this country seems to have been in the colony of Massachusetts Bay, where in September, 1639, it was ordered that births and deaths should be reported to the town clerk by parents and householders within one month, Newly married men were also to give the clerks certificates of their marriage. Similar orders were issued by the Plymouth colony in 1646. Many States at present have laws regarding the registration of vital statistics, but it is so difficult to carry out a law of this character, that the records throughout the country are very imperfect. In 1876, Dr. Bowditch expressed the opinion that no State in the Union, nor the United States as a nation, had any proper system for the registration of vital statistics."

The registration of births and marriages is nowhere complete. That of deaths is believed to be complete, or nearly so, in Boston, Providence, New York, Philadelphia, and Washington. New York, being surrounded by water, is particularly favored in this respect, as the avenues of exit from the city are few and easily guarded. The only way of procuring reports of births and marriages, with any pretension to completeness, seems to be

1 See paper by Dr. J. S. Billings on Registration of Vital Statistics in Am. Journal of the Med. Sciences, January, 1883. The early history of registration in the United States is given by Dr. Sutton as an appendix to the Second Annual Report of Births, Marriages, and Deaths in Kentucky for 1853. He gives nearly all the State laws on this subject in an appendix.

*See Dr. H. I. Bowditch's Essay on Public Health in America. Boston, 1877. Quoted by Dr. T. B. Curtis, in Buck's Hygiene, vol. ii., p. 307.

the rigid and impartial enforcement of penalties in cases of non-compliance with the law.

In the case of reports of death and sickness, absolute accuracy is impossible of attainment. The cause of death is always a matter of opinion, and although opinions may agree in the vast majority of cases, there will always be a sufficient number of deaths in which the cause is extremely doubtful, to vitiate any conclusions that can be drawn from the mortality returns, except relative ones.

In a comparison, therefore, of the deaths and diseases of one period with another, of one locality with another, of one occupation or age, or condition in life with another, of one season with another, will be found the only practically useful conclusions which the hygienist can draw from such data. Under the law of averages, the limits of error and the causes of error will vary with considerable regularity-there will always be about so many faulty diagnoses, so many intentionally false returns, so many omissions to report-so that, even with admitted gross inaccuracies which can never be entirely eliminated, our present statistics properly handled may teach practical sanitarians many useful lessons, especially with regard to the causes affecting the health of small districts.'

1 For comparatively full discussions of these subjects see Vital Statistics, by Dr. T. B. Curtis in Buck's Hygiene; Report of 9th United States Census (Vital Statistics); Essay on Registration, by Dr. C. F. Folsom, in 8th Report of State Board of Health of Mass.; Report on Registration of Prevalent Diseases, by Dr. F. W. Draper, in 7th Report of Mass. Board of Health; Essay on Vital Statistics, by E. B. Eliott, Proceedings of Am. Association for the Advancement of Science, 1856. See also papers on Vital Statistics, by Dr. J. S. Billings, in The Sanitary Engineer, October 4, 1883, et seq.

SOME HINTS TO SANITARY INSPECTORS.

BY FREDERICK N. OWEN.

THE following suggestions for the sanitary examination of buildings or localities are designed for the use of local health officers and those who, in the capacity of family physician, may be called upon to examine into the cause of outbreaks of contagious or infectious diseases; and although by no means exhausting, the subject may, by directing the attention of the inspector to some of their more prominent causes, enable him to elaborate other lines of investigation which will lead him to a solution of the problem. Before beginning an examination of a building or locality which is thought to be, or is complained of as being in an unsanitary condition, the inspector should, first of all, by careful questioning of inmates, neighbors, and others, not excepting children, strive to obtain evidence of offensive odors, disagreeable taste of drinking-water, and the like, that will give him something tangible to work upon. He will often find that this testimony will be uniform in a certain direction, and will save him much time and labor in the investigation he is about to make, by directing his attention to some one point as the probable cause of the trouble. For example, if offensive odors are noticed only when the wind is from the east the inspector would do well to begin his search for the nuisance in that direc

tion.

After having satisfied himself of the nature of the complaint the inspector should note the character of the inmates of the house or houses; their cleanliness, modes of life, dress, occupation, and the like. These points will all give him a general idea of the predisposition of the family to disease, and will sometimes account for the immunity from disease of certain members of a family or a whole household during an epidemic.

Should any one in the house be ill, a diagnosis of the case should be made; and if the disease is found to be preventable, the family physician should be consulted, and all points bearing on the case, such as hereditary or constitutional trouble should be carefully noted. If the beginning of the period of incubation of the disease corresponds with the residence of the patient at some other place than that where the disease appeared, it is safe to assume that the poison was taken into the system at that place. Illness often is developed in a family during the early autumn which has been contracted during the summer in some unhealthy locality. When the cause of disease has been traced in this way to some remote place, the detailed examination of the premises where the person is ill, is of course unnecessary. In cases of oubreaks of contagious diseases the first point to be learned is the date of the first appearance of the disease in the community, after which every condition of food, drink, exposure, intercourse, sewage, and the like, should be thoroughly investigated. In case of illness among children who have attended the same school the school-building should be thoroughly examined.

After having made in this way what may be called the personal part of the examination, and obtained all the information possible, the attention of the examiner should next be directed toward the location and surroundings of the houses in which the disease shows itself. In the case of isolated country-houses the character of the soil on which it stands, viz., sand and gravel, rock, or clay, is an important factor in its salubrity. Rain falling on the surface of a sandy soil sinks rapidly into the ground and renders the site of the house comparatively dry. Clay and rock, on the other hand, being impervious to moisture, water, in sinking through the top soil and coming in contact with them, flows along their surface to some lower point. In this way inequalities in substrata, or fissures in the rocks acting like great bowls, retain large bodies of water, and should a house be situated directly over one of them render it damp and unhealthy. Situations at the base of hills are particularly unhealthy, as the ground water coming from the higher lands is checked in its flow by the sudden change in the grade, and forced to the surface, making the soil more moist than at any other point.

Trees, too, near a house are unhealthy for several reasons: 1, they cast a shade on it and render it damp; 2, they prevent the free circulation of air about it; 3, in the autumn the dead leaves lying on the ground and rotting give off an odor which is considered quite unhealthy.

Neighboring streams, ponds, and marshes sometimes exert a very bad influence on the health of a household or community. The presence of stagnant water is always to be looked upon with suspicion, and measures aimed at its removal should be recommended. Especially is this the case where, from any cause, the level of the water is liable to fluctuate, at times covering the banks, and again leaving large areas exposed. Malaria is generally a companion to these conditions, and will be found to decrease when proper drainage is instituted, and the water-level is made unvarying. In some instances small streams which have received sewage, have been known to carry typhoid contagion to persons in districts through which they flow by the drinking of the water thus contaminated. Although streams so polluted become again fit for drinking by the oxidation of their impurities, it is still a mooted question at just what distance below the point of contamination in the course of a stream its water again becomes wholesome. It is, therefore, best to examine streams as far up as possible when there is any likelihood of their being, or having been used for drinking at the place under examination. Too much attention cannot be bestowed on the wells of the district, and a thorough study of all possible sources of contamination should be made, in addition to the analysis of the water by a competent chemist. A quantitative analysis in all cases is to be preferred, as the examiner is able by it to determine with greater accuracy the probable cause and recentness of the contamination.

The inspector should provide himself with a note-book in which he should record all facts learned by questions and observations, together with sketches of the location, and arrangement of the buildings, their watersupply, plumbing, drainage, etc. Never trust to memory. Enter every little item, no matter how seemingly unimportant. The writer has been saved many an awkward predicament by having every detail jotted down. Besides this, the inspector can much more readily grasp the case, and be able to make an intelligent report by this attention to small matters. When on the ground, time should not be considered an element in the problem. What is required is an absolute mastery of the facts, no matter how long it takes; and in some cases it may take days and even weeks.