AND PLANTS 93 



replaced all the results in his table by a single compromise 

 between them, and had been content to stop there, we 

 should not know the existence of argon to-day. On the 

 other hand, if the chemists of the nineteenth century had 

 paid more attention to the discrepancies in their own 

 experience of nitrogen, if they had not been content to 

 replace their experience and that of Cavendish by a com- 

 promise which neglected his residual bubble, argon must 

 have been discovered long ago. 



Just in the same way, the slight changes in the position 

 of the Earth's axis, by which the latitude of a telescope 

 is changed, not by a change in the position of the tele- 

 scope but by a shifting of the Equator, these changes 

 have only been discovered by examining all the records 

 of experience, and refusing to replace discordant observa- 

 tions by an imaginary uniformity. 



As it is in the two cases we have spoken of, so it is in 

 others. The ideal description of every experience, the 

 description which alone makes further progress possible, 

 is a description of all the results obtained, and not a 

 statement which largely ignores the inconsistencies ob- 

 served. The reason why astronomers, and physicists, 

 and chemists can so often afford to neglect the incon- 

 sistencies of their experience without making themselves 

 ridiculous is that by great labour they have already 

 succeeded in confining the limits within which these 

 inconsistencies occur, so that the proportion of the whole 

 experience affected by them is very small. But biologists 

 have not yet advanced so far as this : the margin of 

 uncertainty in their experience is still so large that they 

 are obliged to take account of it in every statement they 

 make. I tell you that the distance from the Radcliffe 

 Observatory to the Equator is 6,300,000 yards, and you 

 do not care whether the next measurement makes it a 



