Popular Books on Natural Science

. Now, blood is food transformed; food consists of primary elements prepared and

dily like man; the question arises: Whence do they all come, these primary elements that are obliged forever to undergo transformation before they can become animated vital matter? Do the

anew at every moment by food; but it is at every moment, that small particles of the human body die. The

elongs to her, that return to nature what she gave them; but in a

man, spite all his pride, accept her never-ceasing offer; daily he must borrow and daily he must repay in part, until the moment comes wh

d food, of transformed elements of nature, equips his body. But his own blood is at the same time also his cashier, who,

which is immediately changed into vital parts of the body; with every return of

sides, secretes perspiration through the skin. This is a liquid containing water, hence oxygen and hydrogen; but is moreover mixed with various other waste substances of the body, as for example, carbonic acid, nitrogen and fat. Chiefl

his own weight: nay, more-the weight of his perspiration alone, secreted partly by evaporation in t

tter. They return to the primary elements and serve as food principally to

ant, in the shape of food, to animal and man; from these, as waste substances, back again to the primary elements, there to begin anew a circ

more precisely, the "Change of Matter in Man," consists,