498 Mr. G. Walker on the moving the Knight over 







Amalg. 



Amalg. 



Amalg. 



Amalg. 



Amalg. 



Amalg. 



No 



Fluids of the degi-e.es of con- 



of 



of 



of 



of 



of 



of Zinc, 





centration mentioned. 



Zinc. 



Zinc. 



Zinc. 



Zinc. 



Zinc. 



distilled 



37 





Platina. 



Silver. 



Copper. 



Tin. 



Iron. 



Zinc. 



Ammonia (a) 



a>'W'} 



a^w 



a <.w 



a:^w 



a> w 



a > w 





Water {w) 















38 



Sulphuric acid (s) 

 Iodide of potassium {i) 



s<.t 



S> I 



s>'i 



s< z 



s<z 





39 



Hydrochloric acid (s) 



s < z 



s>' i 



s>i 



S> i 



s<: z 



s-<z 





Iodide of potassium {i) 









s<: z 



s>z 



S> 2 



37. With platina, copper, and ^rinc feeble, stronger with szfcer, still stronger 

 with till, and exceedingly strong with iron. 



38. Even with non-heated platina the s < z powerful. The s> z also strong 

 with silver and copper, less so the s <: z with tin. With iron the action ex- 

 ceedingly energetic, first a deflection of 40° in the direction s <: z, immediately 

 succeeded by one of 90° and oscillations between 90° and 80° in the direction 

 s > i' — With rmc just the same, the first deflection in the direction s<:z == 90°, 

 the second in the direction s > z = 90° followed by oscillations between 

 -f 90 and + 75°. 



39. Even with non-heated platina s < z powerful, with it at least no rever- 

 sion. With silver and copper action verj' strong. — With tin the s^'i weak, 

 slowly, and especially after repeated immersion passing into s < i. — With 

 iron only the first deflection of 60° to 70° in the direction s <; z, the second 

 immediately in the direction s >> z =r 90°, then oscillations from + 90° to 

 -|- 80°. — With zinc precisely the same. 



A careful glance at the facts contained in these Tables will 

 justify the correctness of the positions above advanced. I will 

 here draw attention to some distinct cases which will establish 

 them more perfectly. 



[To be continued.] 



LXXV. On the moving the Knight over every Square of the 

 Chess-hoard alternately. By George Walker, Author of 

 various Works on Chess ; a7id Honorary Secretary of the St. 

 George's Chess Club. 



To the Editors of the Philosophical Magazijie and Journal. 

 Gentlemen, 



VOUR Number for the present month has just come into my 

 -^ hands, and I find it contains an interesting paper upon the 

 knight's move, by Dr. Roget, to which my attention is particu- 

 larly drawn, from the circumstance of that essay having, it ap- 

 pears, been suggested by one of my chess articles in Fraser's Ma- 

 gazine (see Fraser of March 1840.). In that memoir, the sub- 

 ject of the knight's circuitous leap was merely touched upon en 



