15|I COMPOUND CARBONATE OF LIME. 



^deposited a sli^^htly yellowish white substance, which, whep 

 washed and dried, weighed 0-l6. Before the blowpipe it 

 immediately became black, and communicated a violet co- 

 lour to borax. In nitric acid it redissolved with efFerveSv- 

 cence ; the nitrate grew black on drying ; and the residuum, 

 tjeated with muriatic acid, gave out oxigenized muriatic 

 a"id, and produced a brown colour, which heat removed. 

 Lastly, prussiate of potash threw down from the muriatic 



solution a white precipitate, without any perceptible mix- 

 deposited. man- ^ ^j rpj^ ^^^,.g ^^^ y^g ^ ^^^ jjj^^ ^^ ^ 

 ganese. , . . ' 



,nate deposited by ebullition was carbonate of manganese. 



Iron left oa the The supernatant liquor contained nothing more. The 

 carbonate remaining on the filter was red. This was dis- 

 solved in muriatic acid, and precipitated by prussiate of pot- 

 ash, which produced a blue prussiate of iron, weig-^liing, when 

 well washed and dried, I'Q. 



The carbonate Five grammes of the carbonate were calcined in a crucir 



bonie acid. 



This substance therefore coataiued, in ] 00 parts, 



Componeafc Lime 43'^ 



t^"s. Magnesia 10 



Black oxide of iron 8 



^ hite oxide of manganese • • 2 



Water and carbonic acid • • • • 36-5 



100. 



A compeund Thus the four carbonates of lime, magnesia, iron, and 

 of fourcaibo- .manganese, which sometimes occur separately in nature, are 

 found united together in the substance, of which an analy- 

 sis has just been given. I do not think there can be any 

 doubt of the presence of the manganese. In one experiment 

 I found four per cent of this metal in the state of white ox- 

 ide: but I have preferred giving the proportion above, whiclj 

 ^consequently is a minimum. 

 These carbo- if the results he! e related be exact, we may conclude, 

 natJis variously j.j.|^^^j^g Carbonates of lime, magnesia, iron, and manganese, 

 may be found ui nature m various proportions ; so that it is 

 no wonder we meet with iron spars without manganese, and 

 others mixed with manganese alone, without lime or magr 



nesia. 



