382 Dr. L. Bleekrode on the Electric Conductivity 



the material was limited. The nitric and phosphoric anhy- 

 drides could not be employed ; and only two gases, sulphurous 

 and carbonic acids, required to be condensed. The former 

 was liquefied by means of a freezing-mixture, the latter by 

 Faraday's method with bicarbonate of ammonia and dilute 

 sulphuric acid. Table II. comprises the results. 



Table II. 





Galvanic battery. 



Induction-coil. 





Anhydrides. 



20 Bunsen 



80 Bunsen 



Spark-1. Spark-1. 



Kemai'ks. 





elements. 



elements. 



15 mm. 



70 mm. 





Sulphurous, S0 2 



o 



Trace of 



o 



Trace of 



D=0 



D = 10 



No spark-discharge, effer- 





den. 



defl. 







vescence at the electrodes. 



Sulphuric, S0 3 



D = 



D = 8 



g= 6 





D=90 



Brisk effervescence at the 

 electrodes. 



Carbonic, C0 2 



D = 



D= 



Trace of 



Spark- 

 disch. 



Tube shattered by the dis- 







G= 



defl. 



charge. 



Boracic, Bo 2 3 



D= 









No conduction of the cur- 

 rent from 950 Bunsen 

 elements (L. & T.). 



Arsenious, As 2 3 



D = 



D=90 





D=10 





Chromic, Cr0 3 



Conductor. 



D = 





D=40 



A black residuum separated 



Osmic, Os0 4 



D = 







Decom- 

 position. 



with the discharge. 



Vanadic, V0 3 



D = 30 









Decomposition and gas 

 evolved by the current. 



Molybdic, MoO s 



Conductor. 











Acetic, (C 2 H 3 0) 2 



D=25 



D=40 



D=4 



Gas libe- 

 rated at 

 electr. 



D= 6 



Brisk evolution of gas and 

 polarization of the elec- 

 trodes by the galvanic 

 current. 



Benzoic, (C 7 H g O) 2 



D- 3 





Spark.- 

 disch. 





With 1 millim. distance 

 between the electrodes, 

 sparks and deposition of 

 carbon. 



Phthalic, C 6 H 4 (CO) 2 



D=20 





D = 6 



No spark. 





With the induction-coil 

 rapid decomposition and 

 gas liberated at both elec- 

 trodes. 



Malic, (C 2 HO) 2 



D = 8 





Decomp., 

 no spark. 





Distance of electrodes = 3 

 millims. 



Butyric, (C 4 H 7 0) 2 



D = 3 





Spark- 

 disch. 





Sparks blue. Distance of 











electrodes = 1^ millim. 



This Table embraces three groups of anhydrides — namely, 

 the anhydrides in which the oxygen is combined with a metal- 

 loid, the anhydrides of the organic acids, and the anhydrides 

 containing metals. The first group includes very bad con- 

 ductors: with the sulphurous and sulphuric anhydrides the 

 conduction is hardly perceptible — deflection, with 80 Bunsen 



