Inorganic Plant Poisons and Stimulants

The work surveys experimental investigations into how several inorganic elements affect plant growth, surveying methods (water, sand, pot and field cultures) and presenting systematic chapters on copper, zinc, arsenic, boron and manganese. For each element it reviews evidence of occurrence in plants, toxic and sometimes stimulatory effects on germination and development, comparisons across higher and lower plants, and physiological considerations that explain dose- and context-dependent outcomes. The author evaluates conflicting results, emphasises the importance of balanced nutrient mixtures and experimental technique, and concludes with practical summaries and references for further study.