Bleaching Pdti^^nMftf^d(Ser and Lead. 4f 



i^ lined ^it!i a beiautifiil rose-colourecl deposit, whicli remains 

 attached to the glass when thp other matters are washed out; 

 but it fades away in^^Tqvt'li^urs, particularly when exposed 

 to light, and cannot ev^i*!''!!^ long preserved in the solution 

 in which it forms. Dissolved in dilute nitric acid, copper is 

 found in the solution and no manganese. There can be no 

 doubt that, like the precipitate, it is the sesquioxide of cop- 

 per in combination with lime. , , . • .,„ ^,u i,^ „,.;+ 



I he red oxide oi iron has also trie power of decoraposiiigj 

 the hypochlorites. This fact, as well as the formation of ^^ 

 superoxide of copper, was observed many years ago by Mr. 

 Mercer of Oakenshaw, and stated by him to the British 

 Associatidti in 1842, in a paper containing some interesting 

 speculations on these and other weak affinities which.,fti,yje!fj^r^e 

 to many of the phaenomena of catalysis. ;;" .^^j' .iVnpcml ^dt 

 'When a solution or bleaching powder is mixed with nitrate 

 of*6pper, alight bluish -green powder precipitates, the bulki- 

 ness of which renders it somewhat difficult to wash. This 

 powder is very slightly soluble in water, and scarcely changes 

 colour in boiling. Heated in a glass tube over a spirit-lamp, 

 chloride of copper sublimes into a cooler part of the tube, and 

 water escapes. The residue consists of black oxide of copper 

 mixed with a quantity of chloride, which may be separated 

 from the oxide by washing. Professor Graham, who sug- 

 gested to me this experiment, remarked the analogous effi^ct 

 of boiling water in separating water from a hydrate. It 

 proved to be a hydrated oxichloride of copper, the substance 

 known by the name of Brunswick green, and formed in a 

 variety of other circumstances. Analysis gave me nearer 

 SCu O, Cu CI than ^Cu O, Cu CI ; but the presence of c^jr^^ ^ 

 bonate in the specimen left me in doubt upon this point, aii4 

 1 could not resume the inquiry. In this reaction the whole 

 of the hypochlorous acid is set free. ^.^ ^.^^^ ^, ^^ ^^^ .^^^ 



\ 'aI^CuO NO5) + 3(CaO CIO, CaCi) >lnin orfj .babhe sd 

 :.'^^,f,(CaO NO5) + 3CuQ„fQuGi + 2Gaei +^ 3CIO. Joq 



. . . L - ' I 1 > !,■ < 1 111 



Peroxide of lead is often produced by passing a stream of 

 chlorine through a solution of sugar of lead. The chloride 

 which accompanies it in this way may be also converted into 

 peroxide by employing a solution of bleaching powder instead- ; 

 of chlorine. The peroxide produced by these means hasia... 

 . light brown colour, although washed with dilute nitric acid 

 and boiling water. I have succeeded, by the following pro- 

 cess, in forming a compound, nearly colourless, of j)eroxide 

 of lead and lime. Dissolve in water 1 lb. of nitrate of lead, 



