“
has stated, 1851–2, that in may be remarkably promoted by impregnating the air with gaseous . For this purpose lumps of the solid salt are so disposed on the heating apparatus of the as to gradually vaporize, or vessels containing a mixture of and may be employed. Care must be taken that the air does not contain at any time more than four ten-thousandths of its weight of the salt; otherwise the foliage of tender plants is injured. Like results were obtained by and Chlebodarow in 1852–3.
— SAMUEL WILLIAM JOHNSON (CHEMIST)