144 



water or on the acid. The instability of tlie acid apparently plays a part 

 especially in the presence of something Nvhich can combine with the oxygen 

 or absorb it (in the case of platinnni) and thns prevent ecinilibrium. 



Very little \^(lrk seems to have been done to determine the canse or 

 causes of the increased activity of nascent elements. Most of the workers 

 have assumed the atomic state as a sufficient explanation. I'attison Muir 

 (Prin. of Chem., p. 10.")) [loints out the need of considering all the 

 I'eactiug substances rather than that ni' the element only, and sites the 

 work of Tommasi (Pogg. P.eililjitter 2.2(1.")) who found that .sodium amal- 

 gam would not reduce a snlutiipn of potassium dilorate but that hydrogen 

 from zinc and dilute sulphuric acid would do so. Muir afterwards found 

 that magnesium, sodium and even a coi)per-zinc ct)uple would reduce (pre- 

 sumably slowly) an aqueous solution of i)ntasi-ium chlorate; but he seems 

 to have overlooked the fact that with zinc and acid the sul)stance reduced 

 is not the chlorate but chloric acid, a much less stable material and conse- 

 quently more easily reduced. Thorpe has found (('. S. Journ. Trans. 1882, 

 2S1>) (hat the rate of reduction of ferric suliihnle varies with the chances 

 which hydrogen has of coming in contact with, the material, and that the 

 rate of reduction in unit time decreases with increased rate of hydrogen 

 ev()lution. He also observed that the jircsence of certain salts, as zinc 

 sulidiate, decreased tlie rate of reduction, and that the nature of tlie metal 

 used intluenced tlie rate. Perhaps the most enlightening results wt-re 

 obtained l»y Traube (P.er. 1.".. cr.it. 2421, 2-t:'.4 ; KJ, 1201) in his work on the 

 constitution of hydrogen pero.xide. lie found that when palladium is 

 charged with hydrogen and made the positive pole of a battery no peroxide 

 is formed but the nascent o.xyiicu is reduced to water. P.ut when such 

 palladium is made the negative pole and molecular oxygen is buljbled 

 around the pole peroxide is i>roduced. If non-hydrog<'nized palladium is 

 used the greatest amount of the pero.xide is icinied (only .ii the negative 

 pole) when all the hydrogen jiroduced is .ihsoibed by the i)alladium, and the 

 amount decreases as the amoiuit of hydi'ogeu more than this increases. 

 With carbon poles no ])eroxide was iinduced at cither ]iole. There seems 

 to be no evidence, however, that hydrogen evolved from carbon iioles did 

 not reduce the oxygen, and it is probable tliat it was reduced to water 

 either directly or throngli the peroxide .is an intermediate jirodiict. The 

 latter is the more iiroiinble since nascent hydrogen r;ipidly reduces the 

 peroxide. 



