Cachet, stamp, and postmark depict Louis Pasteur.
Cachet depicts the wavelength of krypton-86, which was formerly used to define the meter from 1960 until 1983. A meter was defined during this time as the wavelength of the 605 nm (orange) spectral line of a krypton-86…
Cachet, semipostal stamp, and postmark depict Louis Pasteur. A semipostal stamp is a postage stamp issued to raise money for a particular purpose (such as a charitable cause) and sold at a premium over the postal value.
Cachet, semipostal stamp, and postmark feature a portrait of the chemist, François Auguste Victor Grignard. The cachet and stamp also depict the apparatus Grignard used to produce the Grignard reaction, a new method for…
Cachet and stamp depict Claude-Louis Berthollet. Cachet includes text describing Berthollet's contributions to water purification.
Cachet depicts chemical apparatus used in the petroleum industry. Stamp depicts Paul Sabatier, "founder of catalytic chemistry."
Cachet and semipostal stamp depict Gay-Lussac. Cachet depicts a book titled "Law of Gay-Lussac" and various scientific apparatus. Envelope is addressed to Mrs. Richard M. Lawrence, President of the ACS Wives Club.