adapters are used to allow collection of distillates emerging from a condenser.
The simple receiver adapter (1) can be used to direct the distillate into
a conical flask. The jointed adapter (2) would be used with a round bottomed
flask, the vented side arm preventing a closed system which would otherwise
form an explosion hazard. Adapter 3 is designed for vacuum distillations.
The 'pig' adapter (4) allows collection of three different fractions without
interrupting the distillation. The receiving flask can be swapped by rotating
the 'pig' about its joint.