Why is it important to apply drops of water to a glass slide before placing a piece of onion skin on it?

Making drugs is a tricky process. It is necessary to make a correct cut of the substance, use a sterile microscope and cover glass, if necessary, apply a coloring pigment for better viewing of the cells. Water needs to be applied for two reasons. The first is to prevent onion skin cells from losing moisture and making them clearly visible. The second reason is associated with the fact that a drop of water will create tension and allow fixing the cover glass, which will prevent the liquid from drying out and getting various particles on the preparation.