ADAPTERS.--These are tubes of glass of various forms, employed in chemistry to connect together the different pieces constituting an apparatus--as, for example, to join a retort to a receiver during the operation of distillation. You should take care to border the extremities of an adapter; or you may widen them into the form of the mouth of a bottle, when they are to be closed air-tight by corks. Besides this, there is nothing particular to be observed in the preparation of adapters. * * * * * APPARATUS FOR BOILING IN VACUO.--Represented by pl. 3, fig. 19. Employ a tube about a quarter of an inch in diameter. Blow two bulbs; give the tube the necessary curvature; fill one of the bulbs with nitric ether; boil the ether to expel the atmospheric air from the apparatus, then seal the opening in the other bulb. * * * * * APPARATUS FOR FREEZING IN VACUO. _The Cryophorus._--Take a tube one-third of an inch or rather more in diameter, and pretty thick in the sides. Blow a bulb at each end; the first at the sealed part of the tube, the other at the open point; then give to the tube the curvature represented by pl. 3, fig. 32. Introduce as much water as will half fill one of the bulbs; make the water boil, and draw off the point and seal the apparatus during the ebullition. * * * * * APPARATUS FOR CONDUCTING WATER IN BENT TUBES.--Solder a funnel (see FUNNELS) to the end of a tube; pierce two holes in this tube in the same line, and solder to each a little addition proper to receive a cork. Finish the instrument by bending it in the manner indicated by pl. 4, fig. 18. * * * * * APPARATUS FOR EXPERIMENTS ON RUNNING LIQUIDS.--A tube bent once at a right angle, mounted with a funnel, pierced laterally, and soldered at the same point to a smaller tube. See pl. 3, fig. 17. * * * * * APPARATUS FOR EXHIBITING THE PHENOMENA OF CAPILLARY TUBES.--This apparatus consists of a capillary tube soldered to another tube of a more considerable diameter. Sometimes it is bent like the letter U. Pl. 3, fig. 15. * * * * * APPARATUS FOR THE PREPARATION OF PHOSPHURET OF LIME.--An apparatus that can be employed for the preparation of phosphuret of lime, as well as in a variety of other chemical experiments, consists of a tube sealed at one extremity, slightly bent and choked at two inches and a half from the sealed part, and drawn out (after the introduction of the substances to be operated upon) at the other extremity. This little distillatory apparatus is represented by pl. 3, fig. 29. * * * * *