Yale '01S

From WikidChem

Back in 1901, students interested in chemistry were enrolled in a separate subdivision of Yale, Sheffield Scientific School. As you can see from the photo of the class of 1901, it was extremely small (about 15 in the graduating class). However, despite the college's small size, they had a surprisingly well developed knowledge of chemistry. As was a tradition of the "Sheff" students, they took their class picture in front of what is now Watson Hall, decorating the walls with diagrams of various things they had learned. From the drawings, we can see that they knew the molecular formula of methane (CH4). We also see that they knew about oxidation-reduction reactions (Zn + H2SO4 -> ZnSO4 + H+). They also knew about aromatic compounds such as benzene, along with the fact that various functional groups such as OH, NO2, NH3, and SO3 bonded to the benzene ring. They attempted to explain the aromaticity of benzene (note the inward bonding) but were wrong. They also had naming conventions for the various bonding sites for the functional groups (alpha and beta). What is amazing about this is that they learned all this about the molecular structures of the compounds WITHOUT conventional means of examination such as x-ray diffraction, NMR, or IR. As we can see from the photo, the only quantitative devices they had at their disposal were burets and balances. Their main tool was an analytic balance, which was too delicate to cart down from their lab for the picture.

In slide 24, we see the interior of a chemistry lab in Sheffield Scientific School, where SSS is now. We see many of the devices that we have used during the past few weeks in our organic lab, such as a mortar and pestle, buret, and various distillation apparatuses. The central question that all this raises is: how did 19th century chemists learn so much about the molecular structure of chemical compounds, and how were they able to draw such accurate structural diagrams, when they had no possible apparatus for viewing the compounds on such a small scale? This is what we are going to investigate in the next few weeks of the course; we intend to explore the experiments which underlay the theory that organic chemists developed during the 19th century.