- P. Römer & Company Chemical Works fifty billion Mark voucher
This Fünfzig Milliarden Mark Gutschein, or fifty billion Mark voucher, was issued by Chemische Werke P. Römer & Company (Chemical Works P. Römer & Company). Paper features a watermark design.
Chemische Werke P. Römer…
- Chemische Fabrik Buckau one million Mark voucher
This Eine Million Mark Gutschein, or one million Mark voucher, was issued by Chemische Fabrik Buckau. The center includes an embossed company seal. Paper features a watermark design.
Chemische Fabrik Buckau produced…
- Circa 1933
Glenn Joseph writes to Dr. Beckman about the process of finding the right buffer to use in the new glass electrodes inside the pH meter. The identify of the "Dr. Dupont" referenced in this letter is uncertain.
- Addressee Beckman, Arnold O.
- Author Joseph, Glenn
- Subject Electrodes, Hydrogen-ion concentration--Measurement--Instruments, Sunkist Growers, inc., Scientific apparatus and instruments, Hydrochloric acid, Electrodes, Glass, Scientific apparatus and instruments--Design and construction, California Fruit Growers Exchange, Beckman Instruments, inc.
Letter regarding the possible contents of and functioning of the glass electrode in the first pH meter models.
Arnold Beckman invented his first pH meter in 1934 at the request of Glenn Joseph, a chemist from the…