178 Dr. Andrews on the Conducting Po-n^er of certain Flames 



employed, and even the current produced by this simple vol- 

 taic arrano-ement was found to be capable of passing through 

 the flame of alcohol, and of decomposing the solution of the 

 iodide of potassium. 



It is evident from these results that, although the experiment 

 of Faraday which has been described is perfectly accurate, yet 

 it involves some conditions which are not essential, and others 

 which are unfavourable to its success. The conclusions that are 

 derived from it will on this account require to be modified. 



To ascertain whether other flames are capable of transmit- 

 ting in a similar manner the electrical current, the same ar- 

 rangement was adopted, and the larger battery charged with 

 water again employed. The flames of coal gas, ether, hy- 

 drogen, and charcoal were tried, and the passage of the cur- 

 rent through each of them was proved by the occurrence of 

 decomposition. From the quantity of iodine deposited, the 

 current appeared to pass with more facility through the flame 

 of charcoal, and with less facility through the flame of coal 

 <yas than it passed through the flame of alcohol. As the flames 

 were in very different states, this circumstance may not afford 

 an exact method of determining the relative conducting powers 

 of these flames; but even whh a single pair of plates, so large 

 a quantity of iodine was separated when tlie current passed 

 throuo-h the flame of charcoal as to leave no doubt that its 

 conducting power is greatly superior to that of the other 

 flames which were examined. 



The conducting power of the flame of charcoal was further 

 illustrated by obtaining the other effects of electricity from a 

 current passing through it. The poles of the battery of 20 

 pairs of plates, weakly charged with a mixture of dilute nitric 

 and sulphuric acids, were introduced into the flame of a char- 

 coal fire contained in a small furnace and urged by bellows. 

 The diameter of the flame was about five inches, and the poles 

 were two inches apart from each other, and one inch and a 

 half from the sides of the furnace. The current that passed 

 between the poles thus situated deflected strongly the needle 

 of a galvanometer, rapidly decomposed water, and communi- 

 cated a slio-ht shock to the tongue. All these effects ceased 

 when the flame was not in contact with the poles. 



As the flame of charcoal evidently holds a high rank in the 

 list of imperfect conductors, it became an object of interest to 

 determine whether it might be substituted for the liquid in the 

 cell of a voltaic arrangement; whether, in fact, it possesses 

 the properties of an electrolyte. This did not appear to be 

 the case ; for on placing slips of platina and copper vertically 

 opposite to each other in a charcoal flame, and connecting 



