Experiments on various Liquids. 257 



Other Compounds and Solutions. 



27. Amyl sulphocyanide, C 6 H n NS, is positive. As a con- 

 ductor, without the jar, it gave distinct restorations, too faint and 

 quick to be characterized. With strong charges of the jar, 

 the effect was strong, and always distinctly positive though 

 very abrupt, strengthened by tension, and not affected by 

 compression. 



Alhjl sulphocyanide, or oil of mustard-seed, C 3 H 5 CNS, is 

 positive. With strong charges of the jar it gave a clear 

 effect, which was too abrupt for the hand-compensator, but 

 apparently positive. With the Ruhmkorff-discharges the 

 effect was stronger and still very abrupt ; but it was certainly 

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

 pression. With very strong discharges the liquid was con- 

 siderably disturbed. 



Thialdine, C 6 H 13 N S 2 , fuses into a transparent plate at 43° 

 C. In the fusion-cell, with moderate charges of the jar, it 

 gave a clear effect, pretty strong but very abrupt, certainly 

 negative, being regularly strengthened by compression, and 

 not affected by tension. 



Oil of sage is purely positive. The initial extinction was 

 imperfect, the liquid being a weak photogyre. With small 

 charges of the jar, there was a good and purely positive re- 

 storation from extinction. 



28. Several aqueous solutions were tried in the plate cell, 

 but with no results worth mentioning, except in the two cases 

 of CI and S0 2 > 



Chlorine in water is feebly but purely negative. The water 

 was distilled specially for the experiment, saturated with the 

 gas, and then examined immediately. With strong dis- 

 charges of the coil, there were distinct restorations from ex- 

 tinction, very faint but perfectly regular, clearly strengthened 

 by compression, and clearly weakened by tension. The effects 

 were to me barely visible ; but they were as distinct as any 

 very faint effects could be; they were also recovered re- 

 gularly on repetition of the experiment, and with two succes- 

 sive charges of the liquid. 



Bromine in water had been examined some time before, and 

 had been entered in my note-book as very apparently, but very 

 feebly, negative. 



S0 2 in water is also purely negative. The experiment was 

 made immediately after a similar one with water alone ; and 

 the contrast between the two was perfect, water being regu- 

 larly and purely positive, and $0 2 in w T ater as regularly and 

 purely negative, but rather feebler. The solution of sulphurous 



