22 LIFE: ITS ORIGIN AND NATURE 
imals. While it is true that the body-substance 
of all living things is composed of the chemical 
elements known to us, it is also true that these 
chemical elements are combined together in ex¬ 
tremely complex forms—far more complex than 
anything else known to us. To take one ex¬ 
ample: the haemoglobin of blood. A molecule 
of haemoglobin must contain the following 
number of different atoms in their due propor¬ 
tions, viz., of hydrogen atoms, 1,130; of car¬ 
bon atoms, 712; of nitrogen, 214; of oxygen, 
245; of sulphur, 2 and of iron, 1, or 2,304 atoms 
in all. Moreover, if that one atom of iron, in 
its peculiar relation to the rest (“masked,” as 
some physiologists say) were left out, the ani¬ 
mal could neither absorb oxygen nor give off 
carbonic acid,—in other words, it could not 
breathe* How such a combination of atoms 
could have been brought together by mere 
chance is in itself an extraordinary phenom¬ 
enon, which needs considerable explanation! 
The various chemical elements are combined 
organically into more and more complex 
groups, and as this process of building-up 
simple into complex substances proceeds, en¬ 
ergy tends to become “latent,”—which energy 
is, in turn, liberated when these complex sub¬ 
stances are later on broken-down into their 
more simple constituents. The latent pnergy 
Is then liberated and converted into active or 
“kinetic” energy. 
The human body is composed of a variety of 
substances, all more or less complex in char¬ 
acter, of which protoplasm is the representa¬ 
tive and typical example. But protoplasm itself 
