Boyle, R.  Memoirs for the Natural History of Humane Blood (1684).

The first analysis of blood, Boyle's Memoirs may be considered the first scientific study in physiological chemistry, exhibiting methods which have become universally adopted.  This is Boyle's most important medical work.

Robert Boyle (1627-1691) is best known for his formulation of Boyle's Law:  that at a constant temperature the volume of a gas is inversely proportional to the pressure.  He was an active member of the Royal Society, a committed Protestant, a prolific writer, and an excellent scientist, making contributions in physics and chemistry as well as medicine.  His writings on natural philosophy and science helped to spread the Newtonian view of nature and the universe.

(Sources:  Garrison & Morton; Encyclopedia Britannica; Dictionary of Scientific Biography)