Magnetic Permeability of Liquid Oxygen and Liquid Air. 283 



grounds for inferring the existence of a telegonic influence. But it 

 is clear that if there be anything of the nature either of a periodic or 

 of a secular change in stature going on, then since men are taller than 

 women, any group of younger women will appear closer to their 

 fathers than to their mothers, when compared with a group of elder 

 sisters. Thus, no legitimate argument as to a telegonic influence can 

 be based on such a result. I have purposely considered this method 

 of approaching the problem, because it is the method whioK first 

 occurred to me, as it probably may do to others. It can very 

 easily, however, lead to our mistaking for a real telegonic influence 

 an effect of periodic or secular evolution, or, indeed, of different con- 

 ditions of nurture. 



(7) In conclusion, we may, I think, sum up the statistics dis- 

 cussed in this paper as follows : 



(i) So far as stature is concerned there is no evidence whatever of 

 a steady telegonic influence of the male upon the female 

 among mankind. 



(ii) It is improbable that the coefficients of correlation which 

 measure the strength of heredity between parents and off- 

 spring are constant for all classes even of the same race. 



For stature in the case of parents and offspring of both sexes, the 

 value 0'42, or say 3/7, may be taken as a fair working value, until 

 more comprehensive measurements are made. This makes heredi- 

 tary influence in the direct line stronger than has hitherto been 

 supposed. 



(iii) The divergence between the results of this memoir and that 

 of the former memoir on " Regression, Heredity, and Pan- 

 mixia " would be fairly well accounted for, if there be a 

 hitherto unobserved correlation between the hereditary 

 influence and the fertility of woman. 



t; On the Magnetic Permeability of Liquid Oxygen and Liquid 

 Air." By J. A. FLEMING, M.A., D.Sc., F.R.S., Professor of 

 Electrical Engineering in University College, London, and 

 JAMES DEWAR, LL.D., F.R.S., Fullerian Professor of 

 Chemistry in the Royal Institution, &c. Received Novem- 

 ber 20, Read November 26, 1896. 



The remarkable magnetic properties of liquid oxygen were pointed 

 out by one of us in a communication to the Royal Society in 1891,* 



* ' Eoy. Soc. Proc.,' December 10th, 1891, vol. 51, p. 24. See a letter to the 

 President by Professor James Dewar, F.E.S. 



