Hales (1727I 733) discussed the rotting of wounds, cankers, &c., but much had to be done with the microscope before any real progress was possible, and it is easily intelligible that until the theory of nutrition of the higher plants had been founded by the work of Ingenhouss, Priestley and De Saussure, the way was not even prepared for accurate knowledge of cryptogamic parasites and the diseases they induce.
1827) edited the complete works of his mother in seventeen volumes (Paris, 1820-1821), with a notice by Mme Necker de Saussure, and the edition was afterwards republished in a compacter form, and, supplemented by some Ouvres inedites, is still obtainable in three volumes, large 8vo (Didot).
De Saussure in 1808.
The first is the slow-action thermometer which was originally used with good effect by de Saussure in the Mediterranean in 1780.
De Saussure (1767-1845) gave precision to the science of plant-nutrition by use of quantitative methods.