from the Mass of the Blood; especially, since, by a nice Examination of the true inward Texture of all the Bones and Cartilages of the Body, he shew'd how this Oil is communicated to the Mucilage, and so united as to perform their Office. And if one compares what Dr. Havers says of Bones and Cartilages, with what had been said concerning them before him, his Observations about their Frame may well be added to some of the noblest of all the former Discoveries.
These are some of the most remarkable Instances, how far the Knowledge of the Frame of our Bodies has been carried in our Age. Several Observations may be made concerning them, which will be of Use to the present Question. (1.) It is evident, that only the most visible Things were anciently known; such only as might be discovered without great Nicety. Muscles and Bones are easily separable; their Length is soon traced, and their Origination easily known. The same may be truly said of large Blood-Vessels, and Nerves: But when they come to be exquisitely sub-divided, when their Smalness will not suffer the Eye, much less the Hand, to follow them, then the Ancients were constantly at a Loss: For which Reason, they under-stood
