170 Intelligence and Miscellaneous Articles, 



arranged in such an order that each can extend a thin lamina on a 



following one ; it will be seen by the numbers that the order is the 

 same as that for the capillarity, the authority for which is given : — 



Ether 1*89^ 



Acetic ether 2*29 | 



Alcohol 2-49 ^Frankenheim. 



Benzole 2*78 I 



Essence of turpentine .. 2* 78 J 



Soap- water 2- 8 Plateau. 



Acetic acid 2*884 Bede. 



Oil of poppies 3*05 ) 



Bisulphide of carbon .... 3*3] J 



Solution of potash 



Glycerine 4 Plateau. 



Nitric acid 6*026 1 



Sulphuric acid 6' 623 L Frankenheim. 



Hydrochloric acid 7*026 J 



Ammonia 



Sulphate of copper 



• Water 7«58 Frankenheim. 



Chloride of ammonium . . 



Solution of chloride of iron. 



— Poggendorff's Annalen, No. 7, 1869 ; Bibliotheque Universale de 

 Geneve, September 15, 1869. 



Guthrie, 



MEASUREMENT OF THE ELECTRICAL CONDUCTIVITY OF LIQUIDS 

 HITHERTO SUPPOSED TO BE INSULATORS. 



To the Editors of the Philosophical Magazine and Journal. 



Tamworth House, Mitcham Common, S., 

 Gentlemen, September 22, 1869. 



You have given in the August Number of this Magazine an ex- 

 tract from the Comptes Rendus for June, on the '*' Measurement of 

 the Electrical Conductivity of Liquids hitherto supposed to be In- 

 sulators." In a paper read in the Chemical Section of the British 

 Association at Dundee, 1867, 1 gave the resistances, in B.A. units, of 

 a definite length and thickness of oils, and pointed out in some in- 

 stances the electrolysis resulting from the tests. This paper appeared 

 in the Report of the British Association for 1867, the Chemical 

 News, October 1867, and in the Proceedings of the British Pharma- 

 ceutical Conference, as well as in the Pharmaceutical Journal for 

 October 1867. 



Some of the oils operated upon gave much higher resistances than 

 any of the liquids tested by M. Sa'id-Effendi. In the case of oil of 

 turpentine, I found by continued contact with the battery that its 

 resistance became considerably reduced in consequence of electro- 

 lysis, and pointed out the importance of this fact to the detection of 

 oil of turpentine when employed as an adulterant to volatile oils. 

 Yours obediently, 



Thomas T. P. Bruce Warren, 



