Psych ological fn rexf Igatiom 



217 



of the specific gravities. The experiment may possibly iudicjite that the subject 

 apjJH'ciated the notes not by their nunil)er of vibrations, but by their en<*rgy. 

 As some persons can hear a musical note with the air whistle set at 

 much less than "H, it may be concluded that 173,000 vibrations per second 

 are possible with a hydrogen whistle. 



"Mr Iliiwksley is making for mo ati appanitus witli small f,'as Kai,' for hy<irii;;cii pure or 

 diluted, and an india-ruhbor Ixill to squo(>z(^ to (>nal>l<- liydrogcn to \x- used with the whistle 

 wh(<n (leHirud. Tim whistle is tixtnl to the vnd of a hiiiuII india-rubber tube in order to l>e laid 

 luiar llio insect whose notice it may Ik> desired to attract" 



Galton thought it possible that some insects may hear notes quite in- 

 audible to man and he proposed to put this to the test of experiment. I do 

 not know of any report on the results of experiments with this hydrogen 

 whistle on insects. The difficulty for fieldwork, as apart froni labomtory 

 experiment, would l>e the transport of the hydrogen. 



From Hearing Galton turned his attention to the "muscular sen.se," or 

 rather to that combination of senses which tests by lifting weights what 

 dirterence, if any, there is between them'. Galton, adopting Weber's law, 

 took liis weights in geometrical progression, i.e. as 



WR\ WR\ WR\ WR\ etc. 



He chose 11'= 1000 grains and R= 1020 grains and hnd ton varieties taking 

 R to the powers: 



0, 1, 2, .3, 3i, 4^, 5, 6, 7, U, 12. 



He made his weights by charging cartridge cases with shot and closing 

 in the usual way with a wad. If the weights be ninnbered with the power 

 of R, Galton obtained a series of triplets of the following kind : 



Galton chose his lowest weight ( WR") so that it gave a decided sense of 

 weight, and his highest so that it could be handled without sense of fatigue. 

 The te.st consisted in placing the weights in each series in correct order of 



' "An Apparatus for Testing the Delicacy of the Muscular and other Senses in different 

 Persons." Journal of the Anthropological Institute, Vol. xii, pp. 469-75. 

 ' Corrected values ; these are errors in the original paper. 

 • Interpolated to complete series, but not available with Galton's original ten weights. 



PGU 



88 



