Justin Liebig, Animal Chemistry. London, 1843, p. 17f.
CHAPTER VI. THEORIES OF ORGANIC EVOLUTION
 "Essay on the Metamorphoses of Plants," by Goethe, translated for the present work from Grundriss einer Geschichte der Naturwissenschaften, by Friederich Dannemann (2 vols.). Leipzig, 1896, Vol. I., p. 194.
 The Temple of Nature, or The Origin of Society, by Erasmus Darwin, edition published in 1807, p. 35.
 Baron de Cuvier, Theory of the Earth. New York, 1818, p.74. (This was the introduction to Cuvier's great work.)
 Robert Chambers, Explanations: a sequel to Vestiges of Creation. London, Churchill, 1845, pp. 148-153.
CHAPTER VII. EIGHTEENTH-CENTURY MEDICINE
 Condensed from Dr. Boerhaave's Academical Lectures on the Theory of Physic. London, 1751, pp. 77, 78. Boerhaave's lectures were published as Aphorismi de cognoscendis et curandis Morbis, Leyden, 1709. On this book Van Swieten wrote commentaries filling five volumes. Another very celebrated work of Boerhaave is his Institutiones et Experimenta Chemic, Paris, 1724, the germs of this being given as a lecture on his appointment to the chair of chemistry in the University of Leyden in 1718.