t4 Dr, Fvrchhammer on pun Salts of Manga nete, [Jan. 



•gain depofiited on the cover of the crucible, and partly lost. 

 The smallest quantity of sulphuric acid which, in that way, I 

 found combined with 100 parts of protoxide, was 113 parts, 

 which indicates 29*19 parts of oxygen as combined with 100 

 parts of manganese in the protoxide. Berzelius finds only 28* 10, 

 which certainly is too httle. 



From the purest sulphate of manganese, I prepared carbonate 

 of manganese, avoiding oxidation as much as possible ; five 

 grammes exposed during a long time to a red heat in an open 

 vessel yielded 2*803 parts of deutoxide = 2*58776 protoxide. 



Two decigrammes of the carbonate yielded by muriatic acid 

 in a tube with mercury 2*175 French cubical inches of carbonic 

 acid. The weight of the carbonic acid at a medium temperature 

 and pressure is 0*0661 grm. and the salt contains 33*05 per 

 cent, of carbonic acid : 33*05 parts of carbonic acid contain 

 24*036 parts of oxygen ; and, therefore, the 2*58775 parts of 

 protoxide of manganese contain 0*6009 part of oxygen. 



One hundred parts of protoxide contain, according to this 

 experiment. 



Oxygen 23*22 



Manganese 76*78 



100*00 



Or, 100 parts of manganese combine with 30*24 parts of oxygen. 

 The composition of the artificial carbonate of manganese is, 

 therefore, 



1 atom of protoxide .... 61-75,5 {^l^^fs Z;!^^ 

 1 atom of carbonic acid. 33-05 {g^iSe ^xjgen 



1 atom of water. .. .... I3-52o|, '"^"^ hydrogen 



\ 12*018 oxygen 



".;; 98*325 



There was a loss of 1*675, which I imagine consisted of water 

 Aot chllinically combined with the salt. 



Dr.- John, of Berlin, from 150 grammes of crystallized sulphate 

 of manganese obtained 148*5 grms. of sulphate of barytes, and 

 83*25 carbonate of manganese, which, when calculated after my 

 analyses of the Carbonate, indicates 100 parts of protoxide and 

 118*43 parts of sulphuric acid, and 100 parts of manganese 

 combined with 31*03 oxygen, to form the protoxide. It seems, 

 therefore, as if some number between 30*18 and 31*29 is the 

 true number for the oxygen combined with 100 manganese in 

 the protoxide. 



,. On t/ie Deutoxide. 



"Tnii^ colour of tfife deutcxidff is brown, resembling' that of 



