THE PHILIPPINE 
JOURNAL OF SCIENCE 
VoL. 19 JULY, 1921 No. 1 
~ 
THE EXPRESSION OF THE OCTET THEORY OF 
VALENCE IN STRUCTURAL FORMULAS? 
By GRANVILLE A. PERKINS 
Chemist, Bureau of Science, Manila 
ONE PLATE 
The science of organic chemistry, as we know it to-day, may 
be said to owe its very existence to the idea of structural formu- 
las developed by Kekulé, Frankland, and Couper, sixty years ago. 
In the last two decades, however, the development of both organic 
and inorganic chemistry has been greatly retarded by the fact 
that Kekulé’s simple “affinity units” do not represent with 
sufficient accuracy the actual forces which bind atoms together. 
Recent attempts of physicists to apply the new knowledge of 
electrons to the fundamental problem of chemistry, namely, the 
nature of chemical affinity, met with only partial success, until 
Langmuir? finally showed that certain recent ideas of atomic 
structure, notably those of Lewis,* can be used to form a re- 
markably successful working hypothesis in both organic and in- 
organic chemistry. The conception of electron shells and shared 
electrons as presented by him gives one a definite picture which 
is undoubtedly very close to the actual nature of the union 
between atoms. 
Langmuir’s “octet theory of valence” is so simple and exact 
that it will be found of great value to chemists, from the over- 
curious student who asks his professor what makes the atoms 
stick together to the investigator who wishes to predict the 
"Received for publication, February 28, 1921. 
* Langmuir, I., Journ. Am. Chem. Soc. 41 (1919) 868, 1543; 42 (1920) 274. 
* Lewis, G. N., Journ. Am. Chem. Soc. 38 (1916) 762. 
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