Plate XIV, The natural history of the human teeth.

Plate XIV, Copperplate engraving. Illustration showing coss-sections of the root canals of various human teeth and those from a horse. Fig. 19 shows a horse's tooth slit down its whole length, and Fig. 20 the grinding surface of a horse's molar tooth. 'The Natural History of the Human Teeth: explaining their structure, use, formation, growth, and diseases' by John Hunter, 1771.