They are an Organ serving for Respiration, of a soft Substance, and porous as a Sponge, being all over beset with Arteries, Veins, Nerves, and Lymphatick Vessels, and perforated with small Cartilaginous Tubes, that are imparted to it from the Wind-Pipe, and are call'd Bronchia. Their Natural Colour is a pale Red, and marbl'd dark Brown; and their whole Body is wrapt up in a fine smooth Membrane, which they receive from the Pleuron. They are suspended by the Wind-Pipe, by their proper Artery and Vein, and by the Ligatures that fasten them to the Sternum, Mediastinum, and frequently to the Pleuron it self: They are also divided into the Right and Left Parts by the Mediastinum; having four or five Lobes, whereof those on the Left side cover the Heart. Their continual Motion consists in Inspiration, to take in the Air, and Expiration, to drive it out. The Larynx makes the Entrance of the Wind-Pipe
into the Lungs, and the Pharynx that of the Oesophagus or Gullet, at the bottom of the Mouth to pass into the Stomach.
C H A P. XV.
Of the Anatomy of the Head, or upper Venter.
What is the head?
It is a bony Part, that contains and encloseth the Brain within its Cavity.
What is most remarkable in the outward parts of the Head?
The Temporal Arteries, the Crotaphitæ, or Temporal Muscles, and the Sutures of the Skull.
Why are these things considerable?