He loses, they would say, two pounds of blood every week; yet there cannot be more than sixteen or eighteen pounds in his body.

What, then, can cause so abundant a bleeding?
One asserted that in me all the chyle turned into blood; another was of opinion that the air I was breathing must, at each inhalation, increase the quantity of blood in my lungs, and contended that this was the reason for which I always kept my mouth open.

I heard of it all six years afterward from M.Baffo, a great friend of my late father.
This M.Baffo consulted the celebrated Doctor Macop, of Padua, who sent him his opinion by writing.

This consultation, which I have still in my possession, says that our blood is an elastic fluid which is liable to diminish or to increase in thickness, but never in quantity, and that my haemorrhage could only proceed from the thickness of the mass of my blood, which relieved itself in a natural way in order to facilitate circulation.

The doctor added that I would have died long before, had not nature, in its wish for life, assisted itself, and he concluded by stating that the cause of the thickness of my blood could only be ascribed to the air I was breathing and that consequently I must have a change of air, or every hope of cure be abandoned.