134 



JOHN S. BARLOW 



world, but their trend with latitude can be compared, and hence the plots 

 shown in Fig. 5 were constructed from the last column of Table IV. 



Although there is little to choose between the geographic and the geo- 

 magnetic plots with respect to the better fit by the sigmoid curves that have 

 been included, superimposition on the plots of Figs. 2, 3, and 4 is possible 

 only if the geomagnetic parameter is chosen. 



From their data, Grashchenkov and his collaborators (1960) separately 

 examined the effect of maritime climate on the frequency of multiple sclerosis 

 by comparison of the statistics obtained for several maritime cities in the 



TABLE V 



Relative Hospital Admission Rates for Multiple Sclerosis 



IN Selected Maritime Cities in the Soviet Union * 



" Data from Grashchenkov et al. (1960). 



'' 1.0 corresponds to the mean of the percentages for the two cities of greater than 50° geomagnetic 

 latitude (i.e., 3.0%). i 



1.2 - 



1.0- 



0.8 



0.0--- 

 20 



y 



30 40 50 60 70 



GEOGRAPHIC LATITUDE 'N 



20 30 40 50 60 70 



GEOMAGNETIC LATITUDE 'N 



Fig. 6. Relative number of hospital admissions for multiple sclerosis in selected 

 maritime cities of the Soviet Union (see Table V). 



