1058 



(he observed deviations are reached, are large enough to allow iis 

 to assume the equation for tlwse values of t, is known. From this 

 point of view my derivation is, therefore, not open to objection. ^) 

 II. A second objection of 0. and B. refei-s to my assertion loc. cit. 

 that most probably equation 



Q = w{t;)^ w{iy)[t,-d)di} <:^^ (2) 







will be valid. I derive this from the consideration that }r{t) will 

 satisfy the condition : 



•I 



j xv (.'f) d') = 



(3) 



Now 0. and B. are going to prove that this is erroneous. For this 

 purpose they expand w^t) into a series of Fourier. Now it would 

 be thought that the next step they had to take was to examine what 

 inflnence the condition (3) would have on the mean valne of the 

 coeflicients of this series. They do not speak, however, about equation 

 (3), and do not subject the coetTicients to any condition, and they 

 then come to the conclusion that Q might just as well be positive 

 as negative. Now it is not subject to any doubt that if ni{t) is not 

 subjected to any condition, the sign of Q might be just as well 

 -j- as — . It does not require an expansion into series according to 

 Fourier io prove this. But the influence which condition (3) has on 

 this sign, is left entirely unexplained by O. and B. 



^) How greatly Messrs. 0. and B. misunderstand my meaning appears in a remar- 

 kable way from this that on one side when they think they give my views, they 

 repeatedly enunciate theories which are in contradiction with my meaning, but 

 that on the oilier liand when they think tliey are in conlradition with my theory 

 drawing the graphical representation in question on page 429 of their paper, they 

 in fact but represent in drawing a course of ?ü(0" "' entirely in agreement with 

 what I have communicated about this quantity partly in collaboration with Miss 

 Snethlage. 



0. and B. admit that we were right in our contention that this curve begins 

 with the value 0. That also for large value of 1 1 assign the value lo w {t) "'*'^ appears 

 from the equation (1) discussed just now. That further for n (o) > the value of 

 w{t) " *•"' becomes negative for small value of t has already been expressed in the 

 paper by Miss Snethlagk and me on the Brownian movement in the words: At 

 the moment itself that the velocity i» exists the force is independent of \X), so on 

 an average zero; Kq^=^0. After some time however a force will act which exhausts 



