176 Professor 'TyndalVB fiirt her Researches 



Finally, as regards solid diamagnetics, a series of experiments 

 was made with wax ; this also being one of the substances whose 

 negative deportment is urged by M. v. Feilitzsch against M. 

 Weber. 



XV. 



Cylinders of Wax. 

 Length 4 inches. Diameter 0*7. 



The action is very small, but it is nevertheless perfectly certain. 

 The argument founded on the negative deportment of this sub- 

 stance must therefore give way. When we consider the feeble- 

 ness of the action with so delicate a means of examination, the 

 failure of M. v. Feilitzsch to obtain the effect, with an instru- 

 ment constructed by himself, will not excite surprise. 



Thus in the case of seven insulating bodies the existence of 

 diamagnetic polarity has been proved ; the list might be aug- 

 mented without difficulty ; but sufficient, I trust, has been done 

 to remove the scruples of those who saw in M. Weber's results 

 an action produced by induced currents. 



A portion of the subject hitherto untouched, but one of great 

 interest, has reference to the polar condition of liquid bodies 

 while under magnetic influence. The first liquid examined was 

 distilled water ; it was enclosed in thin glass tubes, corked at 

 the ends, and by means of a loop passing round the cork the 

 tubes were attached to the string passing round the wheels 

 WW'. Previous to use, the corks were carefully cleansed, so 

 that any impurity contracted in cutting, or by contact with fer- 

 ruginous matters, was completely removed. The following are 

 the results obtained with this liquid : — 



XVI. 



Cylinders of Distilled Water. 

 Length 4 inches. Diameter 0*65. 



The experiment was many times repeated, but always with the 

 same result ; indeed the polarity of the liquid mass is as safely 

 established as that of iron. Pure water is diamagnetic, and the 

 deflections produced by it are the same as those of all the other 

 diamagnetic bodies submitted to examination. 



