In the sixteenth century, by the labours and researches of George Agricola, a German, and Conrad Gesner, a Swiss, a considerable advance was made in the knowledge of what was called chemical medicine and botany. Agricola, who was the greatest mineralogist the world had then seen, explored and spent much time in the mines of Bohemia and Saxony, and thus obtained a practical knowledge of the then known methods of the working of metals. His contemporary, Conrad Gesner, born at Zurich in 1516, has been called the originator of scientific botany, as he was the first to discover a method of recognising each genus and kind by examining the organs of fructification, and in this way discovered 1800 new varieties. A famous physic garden was planted in Paris in the early part of the seventeenth century by Jacques Gohory, an enthusiastic pharmacist, and this garden eventually became part of the _Jardin des Plantes_. In connection with this garden a school of medicine was founded, the first occupant of the chair of chemistry being William Davisson, a Scotchman, and predecessor to Lefebvre, who afterwards became a chemist at St. James’s. The practice of the teachers of this time was to dictate to their students, and in order to save themselves the trouble of dictating and the students the trouble of writing, which was a very laborious matter in those days, the lecturer would write a book. Thus Jean Beguin wrote a chemical text-book in 1612, which passed through no fewer than fifty-three editions. We must not omit to mention two other pioneers of this period, who made important discoveries in botany; they were Matthias of Lille, who eventually settled in England, and Andrew Cesalpin, professor of botany at Pisa. The former first formulated the true principles of classification of plants and arrangement into families, such as the orchids, palms, and mosses; and to the latter belongs the honour of having devised the first system of botany. Having compared the process of generation in animals to the seeds of plants, he distinguished male plants by their stamens, and those which yielded seed as female.