Scientist removes cell growth medium from a 6–well plate in preparation for a plaque assay, which is a test that… https://www.rawpixel.com/image/2282542/free-photo-image-laboratory-medicine-researchFree Image from public domain licenseWoman looking at a pregnancy test https://www.rawpixel.com/image/427526/pregnant-young-girlView licenseFleta minor. The laws of art and nature in knowing, judging, assaying, fining, refining and inlarging the bodies of confin'd… https://www.rawpixel.com/image/14004896/image-paper-cartoon-personFree Image from public domain licenseFleta minor. The laws of art and nature in knowing, judging, assaying, fining, refining and inlarging the bodies of confin'd… https://www.rawpixel.com/image/14005713/image-cartoon-person-bookFree Image from public domain licenseA German itinerant medicine vendor on horseback selling his wares. Engraving by I. Helman, 1777, after J. Bertaux, 1776. https://www.rawpixel.com/image/13997459/image-dog-horse-cartoonFree Image from public domain licenseChemical cabinet in assaying office at Two Bit Creek. Note the cupels for accommodating sample ore. South Dakota by Russell… https://www.rawpixel.com/image/12146567/image-art-vintage-woodFree Image from public domain licenseAssayer places crucible containing gold ore in furnace. El Dorado Canyon, Clark County, Nevada. Sourced from the Library of… https://www.rawpixel.com/image/12275051/photo-image-person-gold-technologyFree Image from public domain licenseSeparating gold ore samples at assay office. El Dorado Canyon, Nevada. Sourced from the Library of Congress. https://www.rawpixel.com/image/12275268/photo-image-face-person-goldFree Image from public domain licenseAbandoned United States Assay Office. Pony, Montana. Sourced from the Library of Congress. https://www.rawpixel.com/image/12273612/photo-image-wood-public-domain-houseFree Image from public domain licenseOld muffle furnace for assaying gold ores. Two Bit Creek, near Deadwood, South Dakota by Russell Lee https://www.rawpixel.com/image/12146559/image-art-vintage-goldFree Image from public domain license