72 Mr. Binks on the Laws of Action of Voltaic Electricity \ 



action was discovered to have taken place it was either pro- 

 perly allowed tor, the defective plate dismissed, or the experi- 

 ment wholly repeated, and that where comparative estimates 

 were made of the evolved gas or gasses, the proper corrections- 

 were made for temperature and pressure. 



First Investigation. Part I. 



To determine the relative proportions of the zinc and cop- 

 per needed to induce the maximum effect in the action of any 

 simple voltaic circle. 



1st. To determine the influence and its extent of increasing 

 the surface of the copper plate beyond that of the zinc. 



Experiments. — A plate of amalgamated zinc, measuring * 

 square inches on each face, was associated successively with 

 plates of copper, first of an equal size to the zinc and after- 

 wards of a greater size, and gradually increasing in the ratio 

 of the subjoined table. The times of immersion were each 30 

 minutes ; the acid, a mixture of 4j sulphuric (by measure) 

 and 100 parts water, and at the end of each time the acid was 

 renewed and the plate rinsed in clean water and weighed, when 



(Table No. 2.) 



1st, with the copper equal to the zinc, it lost 4*0 grains 



2nd, twice the zinc, it lost... 5*2 — 



3rd, 4 times the zinc, it lost 6*7 — 



4th, 8 times the zinc, it lost 9*0 — 



5th, 12 times the zinc, it lost 15*1 — 



6th, 16 times the zinc, it lost 19*5 — 



7th, 20 times the zinc, it lost 16*6 — 



8th, 24 times the zinc, it lost 17*2 — 



But throughout these experiments the same zinc plate was sub- 

 jected to the action of the acid, and that extending through eight 

 periods of thirty minutes each, or through four hours. And it 

 has been shown above in table No. 1 that a plate of zinc so 

 placed loses more in the second time of immersion than during 

 theirs*. Accordingly, to protect this examination from such 

 a source of error, another plate with the copper equal to it was 

 employed simultaneously and under like conditions, and was 

 weighed at the end of the same times, when it was found to 

 have lost in (Table No> 3#) 



1st time, loss = 4*3 grains = *0" 



2nd time, loss = 4*3 grains = *0 



3rd time, loss = 4-4 grains = -1 In $ive increase 



4th tame, oss = 4-6 grains = -3 I fig^ ^ immer _ 



5th time, loss = 4*9 grains = *6 [ . 



6th time, loss = 5*3 grains =1*0 



7th time, loss = 5*9 grains = 1*6 



8th time, loss = 6*7 grains = 2*4, 



