More than once, in the apparently continuous and unbroken structure of
science, wide gaps have been discovered into which new sections of
knowledge fitted, sections the existence of which had never been
suspected. So in Mendelejeff's _Periodic System of the Elements_ all
chemical elements fitted in without gaps--in a continuous series (except
a few missing links, which were gradually discovered and filled in).
Nevertheless, the whole group of six noble gases, from helium to
emanium, were discovered and fitted into the periodic system at a place
where nobody had suspected a gap.
One of the most interesting of such unsuspected gaps in the structure of
science is the following, because of its pertinency to the subject of
our discussion.
In studying the transformations of matter, the chemist records them by
equations of the form:
(1) 2H_{2} + O_{2} = 2H_{2}O, which means:
Two gram molecules of hydrogen H_{2}(2 X 2 = 4 grams) and 1 gram
molecule of oxygen O_{2}(1 X 32 grams), combine to 2 gram molecules of
water vapor H_{2}O (2 X 18 = 36 grams).
Pages:
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188