144 



water or on the acid. Tlic i!i<tal)i]ity of the add ap]iaicntly jilays a part 

 especially in the presence of soniethini; wiiicji i an cDmliiuc witli tlie oxygen 

 or absorb it (in the case ot' i)iatinuni i and tluis iircvcnt ('(Hiliilirinni. 



Very little wnvk seems tn have been dune t<> determine the canse nr 

 causes of the increased activity af nascent ei"ments. Most of the workers 

 have assumed the atondc state as a sntlicient explanation. I'attisun Mnir 

 (Prin. of Cheni., p. Id.") iioints (int the need of cousirterinj: all the 

 reacting substances rathei' than that of ilie elennMit unly. and sites the 

 work of Toiumasi (PogLC. P.eibljitter 2."_'<i.")) wliu lonnd that sodinm amal- 

 gam would not reduce a solution of potassinm clildi'ate but tiiat hydrogen 

 from zinc and dilute snlphnric acid would do so. .Muir atterwards I'lunid 

 that magnesium, sodium and even a <(ip]ier-/.inc cduple would reduce (]>re- 

 sumably slowly) an acpuvms solution of potas^inn) chlorate; but he seems 

 to liave overlooked the fact that with zinc and acid the substance retbiced 

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

 quently more easily reduced. Thorpe has found (('. S. Journ. Trans. ]SS2, 

 28*.)) that the rate of reduction of ferric sulphate vai'les with the chances 

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

 rate of reduction in unit time decreases with increase<l rate of hydrogen 

 evolution. He also observed that the presen.ce of certain salts. ;is zinc 

 sulphate, decreased the rate of reduction, and tliat the nature of the metal 

 used influenced the rate. Perhaps the most enlightening results wt-re 

 obtained by Traube (P.er. 1.'. (i.".!), 2421, 24:54; 10, 1201) in his work on the 

 constitution of h.vdrogen jieroxide. He found that when iialladinm is 

 charged with hydrogen and made the ])ositive ])ole of a battery no i>eroxide 

 is formed but the nascent oxNiren is reduced to water. P.nt when such 

 palladium is made the negative pole and molecular oxygen is bubbled 

 around the pole peroxide is jiroduced. If non-hydrogeni/.ed palladium is 

 used the greatest! amount of the jiei'oxide is icrmed (only at the negative 

 pole) when all the hydrogen pi-odnced is alisoibed by the palladium, and the 

 amount detn'eases as the amouid of bvdroiriMi more than this increases. 

 With carl)On ix)les no jieroxide was jircduced at citiiei' pole, 'i'liere seems 

 |o be no e\ideni(', however, that hxdi'ogeu evolved f i om carbon poles did 

 not reijuce the oxygen, and it is pioli;ilile that i( was reduced to water 

 either dii'ectly oi' through the peroxide as au iulei-iuedi;it<' product. The 

 latter is the iiioi-e pi-obable siiii-e nascent lixdi-oL'en r;ipidl\ reduces (he 

 ju'roxide. 



