OF THE LATE MB. WILLIAM STUfiGEON. 61 



coated glass produced no sensible shock when passed through 

 the body, a burning sensation only being experienced. He 

 remarks, that " by employing either a moistened thread, or 

 narrow tube of water, gunpowder may be ignited at several 

 interruptions of the same circuit. I have frequently passed 

 the fluid through my own body and fired six guns by one 

 discharge of a jar, and so instantaneous is the ignition at the 

 several guns, that their united reports appear like the report 

 of one gun only." 



In 1830, Mr. Sturgeon published a pamphlet, entitled, 

 " Experimental Researches in Electro- Magnetism, Galvan- 

 ism," &c, embracing an extensive series of experiments, 

 chiefly in relation to the structure and action of galvanic 

 batteries and the dry electric column.* It contains the 

 record of a variety of observations, proving that the strongest 

 chemical action on the positive plates was not always accom- 

 panied by the transmission of the most powerful currents of 

 electricity. Mr. Sturgeon considered these experiments to 

 militate against the chemical theory of galvanism; but a 

 more searching investigation would have convinced him that, 

 in the adduced instances, the chemical action was in a great 

 measure occasioned by minute local circuits on the plates. 

 It was reserved for Dr. Faraday, a year afterwards, to esta- 

 blish the chemical theory in an unassailable position, by his 

 great discovery of the definite chemical action of electrical 

 currents. There are, however, some facts in this pamphlet 

 which have led to practical results of very great importance. 

 I allude, first, to the remarkable change produced in the elec- 

 trical powers of a metal by roughening its surface, such 

 roughening being shown by Sturgeon to render zinc less 

 electro-positive, so much so, that voltaic batteries constructed 

 of no other metals than rolled zinc and cast zinc are " suffi- 



• This work is unfortunately only a fragment. The printer died shortly 

 after a portion was finished, leaving his affairs in a disordered stale. The MS. 

 of the remainder was consequently lost. 



