对一些已知的前体反应性极限的研究，如甲基酮或间多羟基苯发生的反应，表明了物理和化学反应对卤仿产率影响的可变性。对氯、溴和碘的反应性的比较表明，碘仿试验可以全面测定卤仿反应前体。描述了对pH和氨的影响，并列出了反应机理的含义。包括18个参考文献、表格、图表。

A study of some recognized extremes in precursor reactivities, such as occur with methylketones or metapolyhydroxybenzenes, indicates the variability of physical and chemical reactions in their effects on haloform yields. Comparison of the reactivities of chlorine, bromine, and iodine suggests that an iodoform test can give global determinations of haloform reaction precursors. Influences on pH and ammonia are described, and implications of the reactivity mechanism are listed. Includes 18 references, tables, figures.