252 Dr. J. Kerr's Electro-ojrtic 



Butyl nitrate is stronger, giving a sure trace of effect as a 

 nonconductor. Tried as a conductor, with moderate charges 

 of the jar, it gave a strong restoration which was certainly 

 positive, strengthened by tension, but not affected by com- 

 pression. With very strong charges the effect was brilliant, 

 but still too abrupt, being absolutely unaffected by compression 

 parallel to lines of force ; but the contrast between the effects 

 of tension and compression was always perfectly clear. 



Amyl nitrate, a feeble photogyre, is very like the last, cer- 

 tainly, but not quite purely, positive. With strongest charges 

 of the jar, the effect was still unmanageably abrupt for the 

 second test ; and the liquid was sensibly disturbed. 



Nitrites, C„H 2n+1 N0 2 . 



21. Ethyl nitrite was in solution (10 p. c), and, when tried 

 with strong charges of the jar, gave a very faint effect which 

 was apparently positive. 



Amyl nitrite acted well with moderate charges of the jar. 

 Although the liquid was disturbed sensibly by discharge, the 

 regular effect was seen to be certainly positive, strengthened 

 by tension, and either weakened or not affected by compression. 



Other compounds of C, H, 0. 



22. Aldehyd, C 2 H 4 0, is negative, and hardly so strong as 

 ethyl alcohol. With Ruhmkorff-discharges, and with precau- 

 tions against permanent heat-effects, it gave a good restoration, 

 regular though very faint, which was clearly strengthened by 

 compression but not by tension. 



Acetone, C 3 H c O, is stronger than the last, clearly positive, 

 but a very feeble insulator. With good charges of the jar it 

 gave a clear effect, not characterizable. With separate dis- 

 charges of the coil, it gave a fine but still faint restoration 

 from extinction, which was strengthened by tension, but not 

 affected by compression. 



Valercd, C 5 H 10 O, is stronger than the last, and clearly posi- 

 tive. With moderate charges of the jar it gave a good but 

 abrupt effect, strengthened by tension, but not affected by 

 compression. With the coil, the effect was very strong still 

 not affected by compression ; but the contrast between tension 

 and compression was regular and perfectly clear, proving the 

 liquid to be purely positive, but a very weak insulator. 



CEnanthol, C 7 il 14 0, is still stronger, and purely positive. 

 As a conductor, without the jar, it gave a clear though faint 

 restoration. With moderate charges of the jar, the effect was 

 good though still faint, strengthened by tension, and extin- 

 guished by compression. With strong discharges, the effect 



