It is a long, slender tube at one end and the other end has a rubber. Dropper to suck the water to drip into a test tube filled with other substances. In order to see the reaction of the reagent.
The glass tube is a long taper one end and the other side with rubber. The eyedropper is used for absorbing nutrients into the test tube to drip into other substances are contained. In order to see the reactions of chemical reagent.
There is a glass tube at one end and the other end of the slender long rubber tubes are used for vacuum drops to drip into the test tubes in a container is to use other substances in the chemical reaction to the agent.