First published in 1927 as the second edition of a 1914 original, this book examines the effect of various inorganic substances on the growth of plants. Brenchley performs experiments to prove that certain compounds then in use in artificial fertilisers, including arsenic compounds, sometimes had a deleterious effect on the plants to which they were applied in various settings. This book will be of value to anyone with an interest in the history of botany and of agriculture.