Arterial Blood Pressure

Abstract

This passage is from Statical Essays : Containing Haemostaticks, a treatise written in 1733 by an English clergyman named Stephen ales. Although there the 18th century, this experiment of sorts by the Reverend Hales is often cited (97), (346) as an early and dramatic demonstrable pressure -- enough to elevate a column of water some five feet or more.

“In December I caused a mare to be tied down alive on her back; she was fourteen hands high, and about fourteen years of age; had a fistula of her withers, was neither very lean nor yet lusty; having laid open the left crural artery about three inches from her belly, I inserted into it a brass pipe whose bore was one sixth of an inch in diameter... I fixed a glass tube of nearly the same diameter which was nine feet in length then untying the ligature of the artery, the blood rose in the tube 8 feet 3 inches perpendicular above the level of the left ventricle...”