Abstract: An exposure system for supplying a gaseous material, i.e. an aerosol, gas or a vapor, directly to the noses of experimental animals includes concentric vertical inner and outer manifolds. The outer manifold connects with the necks of a large number of bottles in which the animals are confined with their noses adjacent the bottle necks. Readily detachable small tubes communicate with the inner manifold and extend to the necks of the bottles. The upper end of the outer manifold and the lower end of the inner manifold are closed. Gaseous material is supplied to the upper end of the inner manifold, flows through the small tubes to points adjacent the noses of the individual animals, then is drawn out through the bottom of the outer manifold. The bottles are readily removable and the device can be disassembled, e.g., for cleaning, by removing the bottles, removing the small tubes, and lifting the inner manifold from the outer manifold.

Abstract: A foot control for a dental unit having a control unit for the delivery of power to operate dental equipment, and including a plunger to effect a range of speeds for the equipment, said control unit being operated by an actuating member which engages said plunger to depress it, and said actuating member being universally actuated by a pedal selected from a series thereof arranged in spaced relationship upon a base and extending radially from the base and capable of being moved either pivotally in a horizontal plane or depressed vertically downward to actuate said actuating member in one direction to depress the plunger of said control unit to a degree corresponding to the speed desired for the dental equipment.