and Maximum of Magnetism of Nickel and Cobalt, 333 



Table V. 



Cast Cobalt, magnetic, at — 5°C. 

 Experiments made November 28, 1873. 



ft. 



33. 



fX. 



T. 



P. 



3. 



K. 



48-47 



3702 



76-37 



3287 



415 



290-8 



600 



7674 



7254 



91-54 



5760 



1494 



571-1 



7-44 



112-8 



14370 



127-5 



9388 



4982 



1134-5 



1006 



1676 



24130 



1440 



14490 



9640 



1907 



11-38 



264-2 



35860 



135-7 



20420 



15440 



2833 



10-72 



539-9 



53940 



9991 



33010 



20930 



4249 



7-87 



1473 



80760 



54-84 



55920 



24840 



6310 



4-28 



Table VI. 



Cast Cobalt, magnetic, at 230° C. 



Experiments made February 3, 1874. 



:$. 



». 



\i. 



T. 



P. 



3. 



if. 



13-34 



1357 



101-8 



1165 



192 



107 



802 



25-67 



2916 



113-6 



2662 



254 



230 



8-96 



38-55 



4940 



128-2 



4397 



543 



390 



1012 



55-56 



9400 



1691 



7440 



1960 



743-5 



13-38 



7516 



15800 



210-2 



10050 



5750 



1143 



16-65 



101-4 



23920 



235-9 



14260 



9660 



1895 



18-70 



132-7 



31260 



235-5 



17710 



13550 



2475 



18-66 



172-9 



38060 



220-2 



21820 



16240 



3015 



17-44 



281-8 



52520 



186-4 



31160 



21360 



4174 



14-76 



393-6 



63430 



161-2 



39070 



24360 



5039 



1275 



702-9 



82070 



1170 



54920 



27150 



6515 



927 



989-3 



95600 



96-63 



66750 



28850 



7584 



7-67 



1282 



106200 



82-87 



75820 



30380 



8422 



6-57 



Erom Table IV. we see that at ordinary temperatures cobalt 

 does not offer any exception to the general law for the other 

 magnetic metals — that as the magnetization increases, the mag- 

 netic permeability first increases and then decreases. We also 

 see that the results satisfy to a considerable degree of accuracy 

 the equation which I have used for the other magnetic metals. 

 The departure from the equation is of exactly the nature that can 

 be accounted for in either of two ways — either by the heating 

 of the ring by the current for the higher magnetiziug-forces, 

 or by some want of homogeneity in the ring. According to 

 the first explanation, the maximum of magnetization at 0° C. 

 will be somewhat lower than the curve indicates; but by the 

 second it must be higher. I, however, incline to the first, that 

 it is due to heating, for two reasons : first, it is sufficient ; and 

 secondly, the smaller cobalt ring gives about the same maximum 



