(John Conrad), a Physician, and one of the earliest writers on the instruction of the deaf and dumb, was born at Schaffhausen, but in what year is uncertain. In 1687, he graduated at Basle; and, his religious principles not permitting him to settle in his native country, he retired to Holland, where he appears to have devoted his time and attention chiefly to the cure of the defects and imperfections of speech. He first called the attention of the public to his method, in a paper which was inserted in the Philosophical Transactions; and which appeared in a separate form in the year 1692, under the title, Surdus Loquens, sive Methodus qua qui surdus natus est loqui possit; and afterwards, with much additional matter, in 1702 and 1728, under the title, Dissertatio de Loquela, qua non solum vox humana, et loquendi artificium ex originibus suis eruntur, sed et traduntur media, quibus si qui ab incubalibus surdi et muti fuerunt, loquela adpisci, quique difficulter loquuntur, vitia sua emendari possunt. In this work, which Haller terms "vera aureum," he develops, with great ability, the mechanism of language, and describes the process which he employed in teaching its use to the unfortunate class of persons committed to his care. This consisted principally in exciting the attention of his pupils to the motions of his lips and larynx while he spoke; and then inducing them, by gentle means, to imitate these movements, till he brought them to repeat distinctly letters, syllables, and words. As his method was excellent, we may readily give him credit for the success to which he lays claim. In a long course of practice, he says that he never failed in his endeavours, but in two instances; one of which was that of a girl who was an idiot, and the other that of a Jew, from whose father he foresaw that he would not get any thanks for his trouble. The edition of Cælius Aurelianus, which was undertaken by the Wetstens in 1709, and which still ranks as one of the best editions of that author, was superintended by Amman.

(Paul), a Physician and Botanist, was born at Breslau in 1634. In 1662, he received the degree of Doctor of Medicine from the University of Leipsic, and, in 1664, was admitted a member of the Society Naturæ Curiosorum, under the name of Dryander. Shortly afterwards, he was chosen Extraordinary Professor of Medicine in the above-mentioned University; and, in 1674, he was promoted to the Botanical Chair, which he again, in 1682, exchanged for the Physiological. He died in 1691. Paul Amman seems to have been a man of an acute mind, and extensive learning; but a restless and irritable disposition led him to engage too much in controversy, and to indulge in a degree of railing in his writings, which the nature of the subjects hardly warranted. By his first work, which was published in 1670, under the title, Medicina Critica, seu Centuria Casuum in Facultate Lipsiensi resolutorum variis discursibus acuta, he drew down upon himself the displeasure of the Faculty, who had certainly no cause to rejoice at this exposure of their decisions. In the Paracænemis ad discentes circa institutionum medicarum emendationem occupata, which appeared three years afterwards, and in the Irenicum Nuncæ Pompilli cum Hippocrate, which he published in 1689, he showed his independent turn of thinking, by boldly attacking the systems of Galen and Hippocrates, and the abuses to which the implicit adoption of them had given rise. But it is chiefly on his botanical writings that his fame ought to rest. The Suppellex Botanica, et Mænuductio ad Materiam Medicam, which he committed to the press in 1675, contains a full, but somewhat prolix, catalogue of the plants of the botanic garden of Leipsic and its environs, with their synonyms; followed by a brief introduction to the study of the Materia Medica, which proves an accurate knowledge of the science he was then employed in teaching. His next publication was entitled, Character Plantarum Naturalis, ab ultimo fine, viz., fructificatione desumptus, et in gratiam philatrorum per canones et exempla digestus; to the second edition of which, in 1685, he prefixed a dissertation on the true classification of plants. In this work he adopted the arrangement of Morison, endeavouring to show, as the title imports, that the genera of plants were only to