from The Century Dictionary.
- noun A tube filled with some material having a great avidity for moisture, such as calcium chlorid, sulphuric acid, or phosphoric anhydrid, and used to dry a current of gas which is passed through it, or to retain the moisture evolved from a substance so that it can be weighed.
Sorry, no etymologies found.
U-tubes and a sulphuric-acid drying-tube, we now use large cylinders and we have found that the oxygen from liquid air is practically free from carbon dioxide and water-vapor, the quantities present being wholly negligible in experiments such as these.
Through one hole in it was fitted a long funnel; through another ran a glass tube, connecting with a large U-shaped drying-tube filled with calcium chloride, which in turn connected with a long open tube with an up-turned end.
The last of these is joined to another drying-tube.
To this last is joined a drying-tube containing chloride of calcium and anhydrous copper sulphate.
"That forms hydrogen gas," he explained, "which passes through the drying-tube and the ignition-tube.