quainted with the different methods of constructing and ventilating public and private buildings, and would be able to recommend to the local Boards of Health, and to the people generally, those plans which seem best adapted to the circumstances of each case. Such information would be of great importance, whether regarded as contributing to the pecuniary or sanitary welfare of the people.1

1 "The importance of free ventilation will appear from the statement of a few simple

facts

"The object of respiration is to bring the oxygen of the air in contact with the blood, by which the latter is deprived of its carbonic acid, and absorbs a new supply of oxygen. When the atmospheric air is taken into the lungs, it consists of about 79 per cent. of nitrogen, and 21 per cent. of oxygen, and nearly 1 per cent. of carbonic acid; when it is expelled, it is found to have lost about 9 per cent. of its oxygen, the place of which is supplied by an equal amount of carbonic acid. At the same time the blood has undergone an important change, from a dark purple hue, indicative of carbon, which is unfitted for the support of animal life, to a highly oxygenized fluid of a florid red color, carrying health and vigor to every fibre of the body.

"It is not our purpose to inquire into the manner in which these changes are effected: it is sufficient for us that they are produced, and that they are absolutely essential to the existence of animal life.

"As the rapidity with which the air is vitiated is not generally appreciated, the following calculations may not be unimportant: An individual breathes, on an average, from 14 to 20 times in a minute, and inhales from 15 to 40 cubic inches of air at each inspiration. According to Southwood Smith, it appears that in one minute an individual requires 616 cubic inches, or about 18 pints of air; and that, during the same space, 24 cubic inches of oxygen have disappeared, and been replaced by a like amount of carbonic acid; so that, in one hour, each adult person vitiates the air by the subtraction of 1440 cubic inches of oxygen. In one hour the quantity of air inspired amounts to 2 hogsheads, 20 gallons, and 10 pints; in one day, to 57 hogsheads, 1 gallon, and 7 pints; and, during the same period of time, 24 hogsheads of blood, or 1 hogshead each hour, and 144 ounces each minute, are sent to the lungs, to undergo the change already pointed out. Supposing 1 pint of air to be inhaled at each inspiration, which is very nearly the quantity, the amount decomposed is about onefourth, or a quarter of a pint; so that each individual actually vitiates or poisons one-fourth of a pint of air every time he breathes. The rapidity with which this deteriorating process goes on is very clearly shown by placing a mouse under a large, tight glass jar, full of air. In a few moments it becomes uneasy, pants for breath, and in a short time dies in convulsions.

"There is another cause of deterioration of the air, not generally taken into account, which is of considerable importance. An adult gives off, by insensible perspiration, from 12 to 30 grains of vapor per minute; and it is ascertained that the air which has been some time in contact with the skin becomes chiefly carbonic acid gas. Tredgold states that it is desirable to change as much of the air of the room as the moisture given off would saturate in the same time. Accordingly, in a room at 60o, on the supposition, which is probably very nearly correct, that the moisture given off amounts to 18 grains, it will be necessary to change three cubic feet of air per minute for each individual in the room. If the temperature of the room be high, the exhalations of course will be in proportion.

"Our rooms and public halls have also to be lighted at night; and here is another source of deterioration of the air. Each gas-burner is found to consume as much oxygen as eight candles, and each candle renders about 300 cubic inches of air unfit for breathing every minute; so that two candles deteriorate the air as much as one individual. The total quantity of air, then, which will be vitiated by these causes, for each person, will be

By respiration,
By exhalation,
By lights,

Total,

800 cubic inches per minute.

6,416 cubic inches,

Or nearly 4 cubic feet, per minute. It is necessary, therefore, in order to preserve the purity of the air, that the above quantity should be changed every minute. For example: If a room contains 200 people, there should be 800 cubic feet of air changed every minute, or more than would fill a room nine feet square and nine feet high; 400 people will require 1600 cubic feet of fresh air every minute. From the above estimates, any person may calculate the rapidity of deterioration in a close room, of given dimensions, occupied by a given number of individuals.”—Dr. Charles A. Lee: Am. ed. Copeland's Medical Dictionary, Vol. I, pp. 137, 138.

XIX. WE RECOMMEND that, before erecting any new dwelling-house, manufactory, or other building, for personal accommodation, either as a lodging-house or place of business, the owner or builder be required to give notice to the local Board of Health, of his intention and of the sanitary arrangements he proposes to adopt.

The information which such a regulation might secure, would show the growth of a place, and the increase of house accommodations, but it would secure a much more important object. It would place within the possession of the local Board of Health a knowledge of the sanitary arrangements of every house. It is not intended that this regulation should interfere in the least degree with private rights, but confer a mutual substantial benefit. The Board of Health are supposed to possess a much better knowledge, generally, of the methods of constructing dwelling-houses, in regard to the particular sanitary objects they have in view, than the great mass of the people; and few persons, it is supposed, will be found, who will not feel grateful to them for any suggestion which might lead to real improvement. It is designed to be suggestive merely, not compulsory, unless a public injury is inflicted; then it will become the duty of the Board to interfere. A regulation similar to this exists in New York, Philadelphia, and many other places; and is found to work so well as to be worthy of general adoption.

XX. WE RECOMMEND that local Boards of Health endeavor to prevent or mitigate the sanitary evils arising from overcrowded lodging-houses and cellar-dwellings.

Such places are universally acknowledged to be incompatible with health. The hints already given, (p. 145,) have shown the destructive influence of corrupted air. Such air exists in these places, to a great extent, and its deleterious effects should by all proper means be avoided. This matter has attracted much though not the undeserved attention of different sanitary inquirers. Dr. James Stewart, of New York, in March, this year, procured a census of the cellar population of that city, and found that 18,456 persons lived in 8,141 rooms, in 3,741 separate basements. This is about 1 in 25, or 4 per cent. of

the whole population of the city. The proportion of such inhabitants is believed to be nearly as great in Boston. In Lowell, and other places in the State, the same evil also exists. We are pleased that the present legislature, on the 21st of March, thought the subject of so much importance, as to pass the subjoined act. It gives all requisite legal authority to regulate the

matter:

"Whenever the Board of Health of any city or town shall be satisfied, upon due examination, that any cellar-room, tenement, or building, occupied as a dwelling-place within such city or town, is unfit for that purpose, and a cause of nuisance or sickness either to the occupants or to the public, such Board of Health may issue a notice in writing to such persons, or any of them, requiring them to remove from or quit such cellarroom, tenement, or building, within such time as the said Board of Health may deem reasonable. And if the person or persons so notified, or any of them, shall neglect or refuse so to remove and quit within the time mentioned, it shall be lawful for such Board of Health to remove them forcibly, and to close up such cellar-room, tenement, or building, and the same shall not be again occupied as a dwelling-place without the consent in writing of the Board of Health, under a penalty of not less than ten nor more than fifty dollars, to be recovered by indictment of the owner or owners, if they shall have knowingly permitted the same to be so occupied." 2

A detailed account of the results of this highly commendable effort of Dr. Stewart, is being published, while this sheet is passing through the press, in several interesting and valuable articles. See the New York Tribune, June 5th, 13th, 19th, and July 9th.

We are under great obligations to Dr. William H. Duncan, Medical Officer of Health of Liverpool, for the valuable communications on the subject of this recommendation, which are inserted in the appendix. The Edinburgh Review for January, 1850, (p. 217,) in allusion to this matter, says "It may seem hard to deprive the wretch of the bulk-head or empty celiar, which he is content to make his idle home; but it is one of those hardships with which acts of mercy often must begin. When the frightful demoralization of Liverpool was recently exposed, and it was shown that between thirty and forty thousand inhabitants of that fine city lived in dens called cellars, the bold resolution was taken of at once amputating this morbid mass, by rendering cellars illegal habitations. The operation commenced in 1842; and after about 3000 people were ejected, a more stringent method was adopted in 1847. The operation of removal-under the judicious management of Dr. Duncan, the Medical Officer of Health-was gradual, but systematic and steady; and near the end of 1849, 4700 cellars had been cleared of 20,000 inhabitants! Time enough has not elapsed to let the full effect of this bold measure be seen; but the officer of health has already had to report the significant fact, respecting one of the districts formerly most afflicted by poverty and disease, that, while the last epidemic preceding the clearance carried off 500 inhabitants, the cholera, which broke out during the time that the forced change of residence was in progress, slew the comparatively small number of 94."

XXI. WE RECOMMEND that open spaces be reserved, in cities and villages, for public walks; that wide streets be laid out; and that both be ornamented with trees.

Such an arrangement would have a good effect upon the beauty and social enjoyments of the place; but it would have a greater effect upon its general sanitary condition. Vegetation would absorb much of the carbonic acid gas which is produced in so great superabundance in populous places, and thus render the air more fit for respiration. Open spaces also would afford to the artizan and the poorer classes the advantages of fresh air and exercise, in their occasional hours of leisure.

XXII. WE RECOMMEND that special sanitary surveys of particular cities, towns, and localities, be made, from time to time, under the direction of the General Board of Health.

It is of great importance that the exact sanitary condition of every town in the State should be ascertained, that any causes unfavorable to health may be removed or mitigated. Partial attempts have been repeatedly made, by individuals and associations for a general or special purpose, to accomplish this object. Very limited success has, however, attended their efforts. Experience, thus far, has led to the conclusion that no plan can be successful and useful, unless conducted by competent men under the sanction of legal authority.

In 1839 and 1841, Dr. John D. Fisher, late of Boston, issued circulars to obtain information relating to the causes and fatality of consumption. Answers to this important circular were received from thirty-one individuals only.

In 1835, a committee was appointed to investigate the history of intermittent fevers in Massachusetts and New England generally, and a circular was issued and extensively circulated: but two answers only were received. And in 1845, the Massachusetts Medical Society sent other circulars to the several towns in the State, but received a single answer only in

return.

In 1830, the New York Medical Society issued a circular to the different county medical societies, soliciting information concerning the medical topography of that state. Replies relating to the following counties only have been received and

published:-Kings, in 1832; Saratoga, 1833 and 1848; Columbia, 1834; Madison, 1834; Onondaga, 1835 and 1849; Tompkins, 1836; Tioga, 1837; Binghampton, 1843; and Otsego, in 1848.1

The American Medical Association, in 1848-9, made the most successful effort of the kind ever attempted in this country. Answers to their circular were received, giving sanitary sketches of Portland, Me., by Dr. J. T. Gilman; of Concord, N. H., by Dr. Charles P. Gage; of Boston and Lowell, by Dr. J. Curtis; of New York, by Dr. John H. Griscom; of Philadelphia, by Dr. Isaac Parish; of Baltimore, by Dr. James Wynne; of Charleston, S. C., by Dr. P. C. Gaillard; of New Orleans, by Dr. Edward H. Barton; of Louisville, by Dr. L. P. Yandell; and of Cincinnati, by Dr. J. P. Harrison. These papers, including the report of the committee, were published in the Transactions of the American Medical Association, (Vol. II, pp. 431–649,) and also in a separate volume. They are a highly valuable contribution on the subject.

Such surveys are exceedingly valuable and important, and it is desirable that they should be made, for general and not partial purposes, under the direction of the general and local Boards of Health, of several towns each year, until the exact sanitary condition of every part of the State shall be, as far as possible, definitely known. The annual reports of the local Boards of Health might furnish such additional information as would exhibit the changes or improvements which occur from year to year.

The matters which we recommend for consideration in such surveys, the mode by which they are to be conducted, and the manner of presenting the results to the public, may be ascertained by a careful examination of this report; and, especially, these recommendations; the circular; the special reports of the sanitary surveys, which may be found in the appendix; the reports to which we refer in the list of books there recommended; and the circumstances which will suggest themselves to intelligent local Boards of Health.

Transactions of the New York Medical Society, Vol. I, pp. 30, 36, 174, 342, app. 41; Vol. II, p. 228; Vol. III, pp. 25, 151; Vol. V, p. 294; Vol. VII, pp. 61, 96, 131.