Soru

In the early nineteenth century, the emergence of chemical assays for detecting arsenic in human tissue promised to transform criminal jurisprudence. However, early evidentiary doctrine hesitated to grant toxicological findings the status of conclusive proof, treating them instead as merely corroborative circumstantial evidence. This reluctance stemmed not from a judicial distrust of chemistry as an abstract discipline, but from a practical vulnerability in laboratory methodology: the chemical reagents utilized in precipitating arsenic—such as zinc and sulfuric acid—were frequently contaminated with trace amounts of arsenic themselves. Consequently, absent a standardized procedure to test the purity of the analytical reagents independently of the biological sample, an assay could yield a positive precipitate even when the deceased had ingested no poison. Only when procedural norms evolved to mandate rigorous blank testing—running parallel control reactions containing solely the reagents—did courts begin to view toxicological detection as direct proof of ingested poison rather than a potentially ambiguous chemical artifact.

Which of the following inferences regarding early nineteenth-century toxicological evidence is most strongly supported by the passage?