Inside this wedge shaped ventilator are two shelves, pierced with holes, the top one being made to carry a box of charcoal and the bottom one a piece of sponge. By this double contrivance the inventor and patentee, Dr. Howard, of St. John's, Canada, claims not only to absorb the watery vapor of the incoming air by the sponge, and disinfect any foul air that may seek entrance by means of the charcoal, but also to warm the cold air by the amount of friction it has to undergo in its ingress through the body of a ventilator which is already somewhat heated by the warmth of the room. If the wind blows too strongly upon the outside mouth of the ventilator, Dr. Howard proposes a sliding valve to work up and down inside the pane occupied by the apparatus. I cannot but regard such a contrivance as a clumsy one. It may be said to stand in the same relationship to either per feet ventilation or perfect disinfection that spurious freemasonry does to what is called the pure craft masonry, or certain litharges to good white lead. There is no necessity, either, to filter the air of a room in such a manner.
There can, however, be a strong case made out why the water closet pans of a house should be disinfected, and I am able to point 
out an apparatus which fulfils every requirement for that purpose. It is exhibited in the diagram, both in section and elevation, and is known as Brown's patent self acting disinfector. The object is to deliver at every upheaval of the handle a certain portion of a fluid disinfectant; formerly it was exclusively Condy's fluid, now it is chloralum. The construction is the essence of simplicity. In a metal, glass, or earthenware vessel, holding a gallon of disinfecting fluid, a metal siphon is fixed, and the bottom is coiled and has a small inlet as shown, by which means the siphon fills itself. When the closet handle is raised, the water rushing down the supply pipe to flush the basin causes a vacuum in the disinfecting siphon, and its contents are blended with the water. By this means a portion of the deodorizing fluid is retained in the trap or basin where it has no sinecure of work to perform. The siphon refills in a few seconds, and, as only a certain quantity is discharged, a pint of disinfecting fluid, costing one shilling, mixed with sufficient water to make up the gallon, will serve about 140 distinct actions of the closet. The cost of the apparatus is about ten shillings, and it can be fixed in an hour to any patterned water closet whatever. The vessel containing the fluid is usually fixed upon a bracket in a corner above the seat. This kind of apparatus can be fixed to a tap in the stable, or anywhere else, and water containing a percentage of the medicated fluid drawn off into buckets, or run off
