A temporary well-slide (cavity slide) can be made using dental wax available from a drug store (chemist). My sample had 5 cylinders of wax, each 4.5 cm long by 5 mm diameter. A cylinder can be shaped into a ring, warm it in hands and then bend. Press the ring onto a slide, warm gently to soften and melt the contact area (with the slide) and the ring will form a watertight seal.
I filled the cavity with glycerin and it has not leaked for the past two weeks.
Small bugs can be photographed in glycerin (or water, perhaps alcohol) and will keep their 3-dimensional shape.
simple well-slide
simple well-slide
New Brunswick
Canada
Canada