"The repeated respiration of the same atmosphere is _the_ cause of scrofula. If there be entirely pure air, there may be bad food, bad clothing, and want of personal cleanliness, but scrofulous disease can not exist. This disease _never_ attacks persons who pass their lives in the open air, and always manifests itself when they abide in air which is unrenewed. _Invariably_ it will be found that a truly scrofulous disease is caused by vitiated air; and it is not necessary that there should be a prolonged stay in such an atmosphere. Often, several hours each day is sufficient. Thus persons may live in the most healthy country, pass most of the day in the open air, and yet become scrofulous by sleeping in a close room where the air is not renewed. This is the case with many shepherds who pass their nights in small huts with no opening but a door closed tight at night." The same writer illustrates this, by the history of a French village where the inhabitants all slept in close, unventilated houses. Nearly all were seized with scrofula, and many families became wholly extinct, their last members dying "rotten with scrofula." A fire destroyed a large part of this village. Houses were then built to secure pure air, and scrofula disappeared from the part thus rebuilt. We are informed by medical writers that defective ventilation is one great cause of diseased joints, as well as of diseases of the eyes, ears, and skin. Foul air is the leading cause of tubercular and scrofulous consumption, so very common in our country. Dr, Guy, in his examination before public health commissioners in Great Britain, says: "Deficient ventilation I believe to be more fatal than _all other causes_ put together." He states that consumption is twice as common among tradesmen as among the gentry, owing to the bad ventilation of their stores and dwellings. Dr. Griscom, in his work on Uses and Abuses of Air, says: "Food carried from the stomach to the blood can not become _nutritive_ till it is properly oxygenated in the lungs; so that a small quantity of food, even if less wholesome, may be made nutritive by pure air as it passes through the lungs. But the best of food can not be changed into nutritive blood till it is vitalized by pure air in the lungs." And again: