Q. What are capillary veins?
A. Veins as small as hairs running all over the body; so called from the Latin word “capilla’ris” (like a hair).
Q. Do these capillary veins run all over the human body?
A. Yes. Whenever blood flows from a wound, some vein must be divided; and as you cannot insert a needle into any part of the body without bringing blood, therefore these little veins must run through every part of the human frame.
Q. How do hydrogen gas and carbon get into these very little veins?
A. The food we eat is converted into blood, and blood contains both hydrogen and carbon.
Q. How does combustion take place in the veins?
A. The carbon of the blood combines with the oxygen of the air we breathe, and forms into carbonic acid gas.
Q. What becomes of this carbonic acid gas formed in the human blood?
A. Some of it is thrown off by the breath; and the rest of it is absorbed by the blood, to keep up the animal heat.