 So is water H2O? In the end, the answer to this question comes down to how one interprets this sentence. Many chemists would be surprised to find out that water wasn’t H2O, but perhaps this is because they read “H2O” as a shorthand (Weisberg 2005) or as a compositional formula in the manner we discussed in the opening of this section. Water is actually characterized by making reference to both its microstructural and macroscopic features, so this can’t on its own provide a justification for microessentialism.