336 General Notes. [March, | 
PHYSIOLOGY. 
THE SIxTH SENSE.—At a recent meeting of the Anthropologi- 
cal Institute, London, Mr. Francis Galton, F. R. S., exhibited and 
explained some apparatus contrived by himself, with a view of 
testing the muscular and other senses. This apparatus consisted 
of a box, something like a backgammon board, containing trays 
of weights arranged for measuring the relative delicacy of the 
muscular sense (the sixth added by modern psychological science 
to the five recognized by the ancients) as existing in different per 
sons. 
The principle Mr. Galton claimed as a new one. It established, 
he said, a graded scale of sensitivity, and was applicable, by means 
of analogous methods, to testing the delicacy of other senses, such 
as taste and smell. He employed small weights arranged in se 
quence, which were numbered in succession 1, 2, 3, ete., 4 ' 
fered by equally perceptible variations, as calculated by Weber's _ 
law. Hence if a person, A, could just distinguish, say, 1 and $ 
he could also distinguish between any two weights two grades | 
apart, as 2 and 4, 3 and 5, etc. Again, if another person, B, were ; 
twice as obtuse as A, he would be able to distinguish one grade 
only where A could distinguish two. In other words, he eri 
be only just able to distinguish between weights 1 and 5,2 andó, 
and so on. ot 
Generally, the number of grades between the weights that any 
person could distinguish had to be found by trials, and that nut 
ber became the measure of the coarseness of his sensitivity. The i 
weights used were blank cartridges, filled with shot and W re 
care being taken that the shot should be equally distri 1 
hey were arranged in trays, each tray holding_a sega 
