ventilators in a room more valuable than three or four feet additional height of ceiling.  I have found, too, that their working proves how necessary they are, from this simple fact:—­You would suppose that, as the ventilator opens freely into the chimney, the smoke would be blown down through it in high winds, and blacken the ceiling:  but this is just what does not happen.  If the ventilator be at all properly poised, so as to shut with a violent gust of wind, it will at all other moments keep itself permanently open; proving thereby that there is an up-draught of heated air continually escaping from the ceiling up the chimney.  Another very simple method of ventilation is employed in those excellent cottages which Her Majesty has built for her labourers round Windsor.  Over each door a sheet of perforated zinc, some 18 inches square, is fixed; allowing the foul air to escape into the passage; and in the ceiling of the passage a similar sheet of zinc, allowing it to escape into the roof.  Fresh air, meanwhile, should be obtained from outside, by piercing the windows, or otherwise.  And here let me give one hint to all builders of houses.  If possible, let bedroom windows open at the top as well as at the bottom.

Let me impress the necessity of using some such contrivances, not only on parents and educators, but on those who employ work-people, and above all on those who employ young women in shops or in work-rooms.  What their condition may be in this city I know not; but most painful it has been to me in other places, when passing through warehouses or work-rooms, to see the pale, sodden, and, as the French would say “etiolated” countenances of the girls who were passing the greater part of the day in them; and painful, also, to breathe an atmosphere of which habit had, alas! made them unconscious, but which to one coming out of the open air was altogether noxious, and shocking also; for it was fostering the seeds of death, not only in the present but in future generations.

Why should this be?  Every one will agree that good ventilation is necessary in a hospital, because people cannot get well without fresh air.  Do they not see that by the same reasoning good ventilation is necessary everywhere, because people cannot remain well without fresh air?  Let me entreat those who employ women in work-rooms, if they have no time to read through such books as Dr. Andrew Combe’s ’Physiology applied to Health and Education,’ and Madame de Wahl’s ’Practical Hints on the Moral, Mental, and Physical Training of Girls,’ to procure certain tracts published by Messrs. Jarrold, Paternoster Row, for the Ladies’ Sanitary Association; especially one which bears on this subject, ’The Black-Hole in our own Bedrooms;’ Dr. Lankester’s ’School Manual of Health;’ or a manual on ventilation, published by the Metropolitan Working Classes Association for the Improvement of Public Health.