Test Tube Illustration - Scientific Laboratory Equipment Diagram #286198 (License: Personal Use)

This black-and-white engraved illustration depicts a standard cylindrical glass test tube with an open rim and rounded bottom, rendered using fine vertical lines and dotted shading to convey transparency and curvature. The style mimics 19th- to early-20th-century scientific textbooks, emphasizing structural accuracy over realism. It serves as a timeless visual reference for chemistry education and lab documentation.

Used in educational websites, science textbooks, museum exhibits, or historical lab equipment galleries; targets students, teachers, and science historians seeking accurate, public-domain illustrations of basic labware.