NATURAL SCIENCE TO GENERAL SCIENCE. 31 



are preserved in ancient histories. Conversely, many of 

 the important data of astronomy for instance, the in- 

 variability of the length of the day, and the periods of 

 several comets rest upon ancient historical notices. Of 

 late years, physiologists, especially Briicke, have actually 

 undertaken to draw up a complete system of all the 

 vocables that can be produced by the organs of speech, 

 and to base upon it propositions for an universal alphabet, 

 adapted to all human languages. Thus physiology has 

 entered the service of comparative philology, and has 

 already succeeded in accounting for many apparently 

 anomalous substitutions, on the ground that they are 

 governed, not as hitherto supposed, by the laws of eu- 

 phony, but by similarity between the movements of the 

 mouth that produce them. Again, comparative philo- 

 logy gives us information about the relationships, the 

 separations and the migrations of tribes in prehistoric 

 times, and of the degree of civilisation which they had 

 reached at the time when they parted. For the names of 

 objects to which they had already learnt to give distinc- 

 tive appellations reappear as words common to their later 

 languages. So that the study of languages actually gives 

 us historical data for periods respecting which no other 

 historical evidence exists. 1 Yet again I may notice the 

 help which not only the sculptor, but the archaeologist, 

 concerned with the investigation of ancient statues, 

 derives from anatomy. And if I may be permitted to 

 refer to my own most recent studies, I would mentionl 

 that it is possible, by reference to physical acoustics) 

 and to the physiological theory of the sensation of hear-/ 

 ing, to account for the elementary principles on which 

 our musical system is constructed, a problem essentially 

 within the sphere of aesthetics. In fact, it is a general 

 principle that the physiology of the organs of sense is 

 1 See, for example, Mommsen's Rome, Book I. ch. ii. Tn. 



