210 



than compact masses, from which it is evident that the action is here 

 li:isp<l on contact i .- Introduction). It is enough to hrinij hydrogen 

 peroxide into contact \\ith charcoal, e/old, the peroxide of manganese 

 or lead, the alkalis, metallic silver, ami platinum, to bring about the 

 above decomposition.*' 1 l>e>ide> which, livdro^eii |>ero\ide forms water 

 and part- with it> oxv^'en \\ith uivat ea-e to a number of substances 

 which arc capable of being oxidised or of combining \\'ith oxygen, and 

 in this respect i- very like ozone and ot her /,mr, /_/'/// ,,.,'i<lis' /-x.'-' 1 To 

 the numlier of contact phenomena, which are so natural to hydrogen 

 peroxide, as a substance which is unstable and ea.-ilv decomposable with 

 the evolution of heat, must be referred the following- -that in the pre- 

 xeiice ot many substances containing oxvu'en it evolves, not only its own 

 oxvgen. but also that of the substances which are brought into contact 

 with it that i-. /'/ <'<(* In <> r<-<l//<-i/ir/ indnm-r. It behaves thus wit h 

 ozone, the oxide^ of silver, mercury, gold and platinum, and lead 

 peroxide. The oxvgen in these -ubstances is not stable, and therefore 

 the feeble inllueiice of contact is enough to destroy its position. 



i'i - -t a IT] i. ci rt a in (it tin 1 r<i/ttli/t /<' i>r contact jiliriK 'iiu-na 



timi. wliiNt. h.. Wfv.-r.it (l...sii..t iiltrr tin- S.TH-S of c-Iimip-s 

 liens ..nly. I'n.f.-sscr Scli.".n.- of tin- 1 '.! mtT-ky . \i-a.lnny. 

 i idy cxjilainc.l a nninli.T of i 1 . -act ions of h\ driven peroxide \vliich prrviou-ly \\ '!< 



,.1 und'-r-i 1. Tim-, for instance, lie showed iliat witli liydrop-n jicroxidc. alkali^ "'ivc 



IH I'M id. - n: the alkaliin' metals, \\hirli cMinliinc \\-ith the remaining hydrc.Li'i'ii pci'Mxiilf. 



un-talilc f nil] Mimd- \vhirharc easily decoiii]ioscd. and therefore allcali- evince 



,i di-ciiin]in iT.talvtii i Iliience mi - ihilimis of hydrogen |>eroxide. Only acid >'ln- 



|.ei'Mxide. and tht-n ..nly dilute ones, can !.. pre-erved well. 

 : "" // ''//"'-. a- a -nil-:.-, nee conlaiiiin^ nnirh Mxvu f en ( namely. Id ]iart> to 



ar-eiKc. CM ' in.- intu cal. ide, the oxides of x.inc and cMjiper into jx-roxides ; 



I p.irt- wit en 1 m\ suljiliide-. I-MII\ ei'tin.L; th.'in iiit.. sulphates, iVc. So. lur 



, vain],!. . / . iTl I !; cli 1, ad r-lllpllide. I'l.S. into \\hite lead .lllphate. I'I, SO,. CM]. per 



. -I i er ^nlphate. and -o MH. The iv-iMrali.ii i of ..Id ..il pa i nt in--- 1 1\ liydrM-vn 

 : . I. i- lia-i .1 MII this a li-iii. Oil-, IMHI'S are n-nally admixed with wliite lead, and in 



it | true. M| 1 inie. This i- ]>art ly 



: .. to tin ilphn elli-d li\.h.i/.n cMiitained in (he air. \\hi.-h acts MM white lead. 



i.-ad ulj.hi.l.'. whieh i- Mark. The intermixture .,| the I, lark colMiir darkens the 



r. t. In i-I. i tureuitha ..luli..ii <.f h\.lr,,-.-n |.i-r..\il.-. tin- lilai-k li-atl stilpliiilr 



nf il.. i i il-i i !.... ....,: , . M them. HxdiM-en pn-Mxidr oxidisi-s 

 with it " '1 ' nl.:, MM. . Tim it , mpM.-,,-, h\ dri.. die acid, sett in^ the iodine 



fl'. e and CM|,\r-f1 tin I.T ; il I. I'MinpM-es -Illplmretted 



in in <: art lh< er. t! ihe ; iilplmr Ire... Starch paste with 



, did. t. I i. u. ,r. direr! , ; , ( ,,. , ,f huln.p.,, in the entire 



:d,-ence .,f tree ... id : Lilt I he a dd i t i..| , , ,| ;, s Ilia 1 1 . | Ua 11 t it V of in .)! Illphate I- feel i \ itl'i.ill 



,, i- ,,f l..,id aci lal J,, 1 hi' m:\tnr. i . : .. .!i . 1 1 I . i r , , i , r , -i . i ,!,,,-],, .,, t ),,. p ;l .,t,.. This i:, a very 

 ,..'.' .::] , ; h\drM . . , d-.. the test with i-hroniii- iiriil 



i.lirl fill, i ' N"1 - 



