PROFESSOR TYNDALL ON THE DIAMAGNETIC FORCE, ETC. 
7 
net, the cube, if in an oblique position, turned and set its fibre equatorial. By suit- 
ably breaking and closing the circuit, the cube could be turned 180 ° round and held 
in this new position. The axial position of the ligneous fibre was one of unstable 
equilibrium, from which, if it diverged in the slightest degree right or left, the cube 
turned and finally set its fibre equatorial. The following is a statement of the results 
obtained with thirty-five different kinds of wood : — 
Table I. 
Name of wood. 
Deportment of 
mass. 
Deportment of 
structure, 
Remarks. 
1 . Rppf-wood 
Diamagnetic. 
Fibre equatorial. 
2. Black Ebony 
3. Box-wood 
4. Second specimen 
5. Brazil-wood 
6. Braziletto 
Action decided. 
7 . Bullet-wood 
Action decided. 
8. Cam-wood 
9 . Cocoa-wood 
10. Coromandel-wood 
11. Green Ebony 
Action strong. 
Action strong. 
Action strong. 
1 2. Green-heart 
13. Iron- wood 
14. King- wood 
Action strong. 
15. Locust-wood 
16 . Maple 
Action decided. 
17 . Lance- wood 
Action decided. 
1 8. Olive-tree 
19 . Peruvian-wood 
Action strong. 
20. Prince’s-wood 
21. Camphor- wood 
22. Sandal-wood 
' 
23. Satin-wood 
' 
24. Tulip-wood 
25. Zebra-wood 
26 . Botany Bay Oak 
27 . Mazatlan-wood 
Action strong. 
Action decided. 
28. Tamarind-wood 
29* Sycamore 
Action decided. 
30. Beech 
Action decided. 
31. Ruby-wood 
32. Jacca 
33. Oak 
Action strong. 
Action feeble. 
34. Yew 
35. Black Oak 
Paramagnetic. 
Action decided. 
The term “ decided ” is here used to express an action more energetic than ordi- 
nary, but in no case does the result lack the decision necessary to place it beyond 
doubt. It must also be remarked that the term strong ” is used in relation to the 
general deportment of wood ; for, compared with the action of many other diamag- 
netic bodies, the strongest action of wood is but feeble. Simple as the problem may 
appear, it required considerable time and care to obtain the results here recorded. 
During a first examination of the cubes eight anomalies presented themselves — in 
