William Jevons. "The Power of Numerical Discrimination", an article in Nature, 9 February 1871, occupying pp 281-283 (but a tightly-packed, tightly-printed 4,000 words) in the issue of pp 281-300. Offered in the original weekly issue, removed from a larger bound vilume, but with the original front wrapper and 4-pp of ads. Scarce in this format. VG condition. $250
- "IN an article with this title in a recent number of NATURE, Mr. W. S.
Jevons offered the results of some ingenious experiments he had been
making to determine how many objects the human mind could count by an
instantaneous and apparently single act of attention. He comes to the
conclusion that the power of his mind was limited to something less than
five."--review in Nature 3, 367-367 (09 March 1871)
- "In a remarkable brief note in Nature, 1871, W. Stanley Jevons described the results of an experiment he had conducted on himself to determine the limits of the number of objects an observer could comprehend immediately without counting them. This was an important philosophical question: How many objects can the mind embrace at once?"
"He carried out 1027 trials in which he tossed an "uncertain number" of
uniform black beans into a box and immediately attempted to estimate the number
"without the least hesitation". His questions, procedure and analysis anticipated
by 75 years one of the most influential papers in modern cognitive psychology
by George Miller (1956), "The magical number 7 plus or minus 2: Some limits on
For Jevons, the magical number was 4.5, representing an empirical law of
complete accuracy."-- By Vincent Arel-Bundock, http://vincentarelbundock.github.io/Rdatasets/doc/HistData/Jevons.html