The spinal fluid itself is a secretion of another gland at the base of the brain, the choroid.

The fluid used for cooking may be water, milk, or a mixture of both; also soup stock, tomato juice, or any preferred liquid.

Now, what led you to believe that fluid to be blood?"

That fluid was therefore no filtrate, but a secretion.

Within a certain time a vesicle appears in the place of the wound, and the fluid which distends this vesicle is vaccine matter, in quantity a hundred or a thousandfold that which was originally inserted.

He found the fluid to be perfectly innocuous,pure honey, and nothing more.

When the atmospheric fluid is homogenous and of equal density, the rays of light pass without obstruction or alteration in their shape or direction; but when they enter from a rarer into a denser medium, they are refracted or bent out of their course; and this with greater or less effect according to the different degrees of density in the media, or the deviation of the ray from the perpendicular.

Blood when shed from the living body is as fluid as water.