An example of metaphor and analogy in popular science writing:
"For example, there are two varieties of snails, which are identical in all other respects, but differ in the way they build their house: one variety has the shell spiralling clockwise, whereas the other spirals in a counterclockwise [i.e.., anticlockwise] way. Even the so-called molecules, the tiny particles from which all different substances are built, often possess right- and left-handed forms, very similar to those of right and left gloves, or clockwise and counterclockwise snail shells."
George Gamow (1961) One, Two, Three…Infinity. Facts and speculations of science, Revised Edition, Dover Publications, Inc., New York.
Snail shells are only 'houses' metaphorically (and this might be seen as an anthropomorphic metaphor).
The analogy between optical isomerism of molecules, and the handedness of gloves (or helices) is a common comparison.
Read examples of scientific analogies
The suggestion that all different substances are built from molecules is incorrect as metals such as iron and salts such as sodium chloride do not contain any molecules. Gamow was a physicist and physicists sometimes disregard differences between atoms and molecules even though these differences are important to chemistry. So, it may be that Gamow did not actually hold this alternative conception himself (rather he may have just been using economic phrasing), but this could encourage the misconception in readers.
Read about the nature of alternative conceptions
Read about some examples of science misconceptions
Read about historical scientific conceptions
