|2002 Little Fun Book of Molecules Humans, by American writer John Hodgson, containing 98 chemical aphorisms on similarities between humans and molecules. The cover seems to allude to the idea that certain people adhere to each other similar to how liquid water molecules form droplets on a surface. |
450BC: Empedocles' aphorisms
The first and foremost to state chemical aphorism was Greek philosopher Empedocles and his circa 450BC suppositions on how humans behave as if they were types of chemicals. Empedocles famously explained the mixing of social groups on the model of the chemical solubility of liquids in stating that: 
“People who love each other mix like water and wine; people who hate each other segregate like water and oil.”
Another variant of this famous human chemistry quote is: 
“Relatives mix like water and wine; enemies avoid each other like water and oil.”
There seems to more of these given by Empedocles, which need to be tracked down.
1995: Lehn’s aphorism
In the founding 1995 book of the science of supramolecular chemistry, Supramolecular Chemistry: Concepts and Perspectives, French chemist Jean-Marie Lehn gives a detailed Goethe-style chemical aphorism on the second opening page of his textbook: 
“Supramolecular chemistry is a sort of molecular sociology! Non-covalent bonds define the inter-component bond, the action and reaction, in brief, the behavior of the molecular individuals and populations: their social structure as an ensemble of individuals having its own organization; their stability and their fragility; their tendency to associate or to isolate themselves; their selectivity, their ‘elective affinities’ and class structure, their ability to recognize each other; their dynamics, fluidity or rigidity or arrangements and of castes, tensions, motions and reorientations; their mutual action and their transformations by each other.”
2002: Hodgson's aphorisms
In 2002, similar in theme to Greek philosopher Empedocles analogies of how people how like each other mix like water and wine, American writer John Hodgson published a short booklet of of sayings intended to look at the similarities existing between humans and molecules. In back cover synopsis of his book, Hodgson states “this book looks at how molecules behave as compared to human behavior with the use of metaphors and other common similarities.” Each page of the book contains a different aphorism of which below are shown a few representative examples: 
“Different molecules or humans behave differently having different reactions or behaviors to changing situations.”
“When molecules or humans mesh they have chemical or physical reaction and or reproduction.”
“With experiment we can better understand these molecules or humans like we never knew before.”
“Molecules and humans take in elements or food.”
“Molecules and humans engage in different behaviors and or sex.”
“Molecules and humans make or change common bonds.”
All-in-all, Hodgson’s book contains ninety-eight of these aphorism sayings. To note, many of Hodgson's aphorisms are rather incoherent and, in many cases, having almost nothing to do with human chemistry.
1. Aphorism – Online Etymology Dictionary.
2. Allan, Forbes. (1999). Milton's Progress. Publisher.
3. Lehn, Jean-Marie. (1995). Supramolecular Chemistry. VCH.
4. (a) Hodgson, John. (2002). Little Fun Book of Molecules/Humans. 1st Books.
(b) Hodgson, John. (2010). molecules humans. Lulu.com.
5. Thims, Libb. (2007). Human Chemistry (Volume One) (pg. 169). Morrisville, NC: LuLu.
6. Mimkes, Jurgen. (2001). “Chemistry of the Social Bond” (German → English) (Chemie der Sozialen Bindung), University of Paderborn.
● Aphorism – Wikipedia.