Liebig's Alkaloid Analyses: the Uncertain Route from Elemental Content to Molecular Formulae
Bibliographic record
Abstract
Liebig's 1831 paper that describes a new apparatus for the analysis of organic compounds and the results of several analyses using the apparatus is a justly famous contribution to the evolution of modern chemistry. In this paper, I look at the three separate components of Liebig's combustion apparatus that collect the water, carbon dioxide and nitrogen released by the combustion of six alkaloids. Gravimetric data included in the paper reveal that very accurate results could be obtained for water by absorption in a calcium chloride tube, and even better results for carbon dioxide resulted from use of the Kaliapparat. Volumetric measurement of nitrogen gave very poor results despite Liebig's efforts to improve it. Inaccuracies in nitrogen measurement made consistent construction of accurate molecular formulae for nitrogenous substances impossible, and only fortuitous decisions intended to bring molecular formulae into agreement with measured combining weights gave formulae in agreement with modern ones, as in the case for quinine.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".