EDUCATIONAL EQUIPMENT-NAMELY, AN APPARATUS FOR PERFORMING EXPERIMENTS REQUIRING THE ABSENCE OF FRICTION; AND AN APPARATUS FOR DETECTING THE VISIBLE EFFECT OF CIGARETTE SMOKE BY MECHANICALLY PUFFING A CIGARETTE TO SHOW RESULTING COLOR STAIN ON A FILTER

APPARATUS FOR TEACHING ABOUT WATER ANALYSIS, CHEMICAL REACTIONS, ELECTRONICS, GENETICS, BLOOD AND GENERAL SCIENCE AND BIOLOGY