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 {187} 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.