We review our procedures for selecting, preparing and analyzing meteorite samples, present new analyses of 16 ordinary chondrites, and discuss variations of Fe, S and Si in the L‐group. A tendency for Fe/Mg, S/Mg and Si/Mg to be low in L chondrites of fades d to f testifies that post‐metamorphic shock melting played a significant role in the chemical diversification of the L‐group. However, these ratios also vary widely and sympathetically in melt‐free chondrites, indicating that much of the L‐group's chemical variation arose prior to thermal metamorphism and is in that sense primary. If all L‐chondrites come from one parent body, type‐correlated chemical trends suggest: 1) that the body had a traditional “onion skin” structure, with metamorphic intensity increasing with depth; and 2) that it formed from material that became more homogeneous, slightly poorer in iron, and significantly richer in sulfur as ac