In human chemistry, Mary Brown Mesny (c.1880-c.1950) was an American writer-philosopher noted for her 1910 “Human Molecules” on a person as a molecule.
In 1910, Mesny, in her “Human Molecules”, digressed on the subject of the human molecule, in which she specifically defines people as atoms or molecules, "nothing more nothing less", that must satisfy their bonding affinities, just as oxygen (two bond affinities), hydrogen (one bond affinities), and carbon (four bond affinities) have predisposed numbers of affinity bonds (valencies). On the subject of prediction and human chemical bonding, Mesny states: 
“It is a happy thought that certain lovely combinations are foreordained, and that these human atoms often meet their mates.”
Mesny’s article seems to be the first article on human molecules, prior to American philosopher Alan Nelson’s 1992 chapter “Human Molecules”. 
1. Mesny, Mary B. (1910). “Human Molecules”, The Smart Set: a Magazine of Cleverness, 31:100, May.
2. Nelson, Alan. (1992). “Human Molecules”, in: Post-Popperian Methodology of Economics, ch. 3, pgs. 113-33) by Neil De Marchi. Kluwer Academic Press.