Where did the expression "blue blood"

The aristocrats

All at least once in my life heard or used expressions such as "blue blood". Sometimes it defines a very skeptical attitude or the allocation of the total mass of certain individuals possessing a range of characteristics that directly or indirectly, objectively or subjectively forced to put them separately in a series of many, or persons of noble birth and of origin related to an ancient aristocratic family.

The expression does not mean great color blood cells, flowing in the veins of these objects, however, the story of the origin of this catch phrase associated with the structure of the blood. Long been known that persons of noble blood, as a rule, stood out kipelno white skin, even a light tan was the lot of the laborers and peasants. It is implied that in the veins of these subjects bleeding unnatural bluish tint that gives them similar other than color.

The expression blue blood has Spanish and French roots.

Knights

According to another version, particularly the medieval knights of noble birth did not shed a drop of good substance in the unfolding events, thanks to its special properties and the blue. Even the Inquisition treated people with a similar anomaly with deep respect and fear, saying that such colors symbolize certain heavenly power.

Blue blood in nature

Blue blood found in nature, as the color of blood is determined by nothing more than its composition. Blue blood is often found in marine fauna, spiders, crustaceans, this trait due to a particular substance hemocyanin, which unlike human has magnisoderjasimi blue pigment.

Kianetiki - so scientists call people with such a natural anomaly.

Blood cells, have a reddish tint in the veins of these people acquire a blue color due to the higher content of copper, which does not affect the ability of blood to carry oxygen. Such individuals, according to statistics, there are more than seven thousand people, their blood has grayish or purple hue, and this fact is more the exception than the rule, therefore, the expression blue blood - the phrase is rather portable than direct meaning.