3^6 Dr. Thomas Thomsoji on the [Nov. 



pitate became brown by exposure to the air, and by ignition 

 acquired a reddish tint. In this state it was red oxide of 

 manganese. It weighed 5*78 grs. = 5-38 gr. of protoxide 

 of manganese. 



The ammoniacal liquid which passed through the filter 

 being evaporated to dryness, and the residue re-dissolved 

 in water, left a small quantity of matter, which became red 

 by ignition, and was also red oxide of manganese. It 

 weighed 0*07 gr. = 0*065 gr. of protoxide. So that the 

 whole protoxide of manganese contained in 16*26 grs. of 

 the salt amounts to 5*445 gr. 



The liquid thus freed from base was treated with nitrate 

 of silver. The chloride of silver obtained, weighed after 

 ignition, 0*5 gr. = 0*12 gr. of chlorine. 



The excess of silver being removed by the addition of a 

 little common salt, the liquid was precipitated by muriate 

 of barytes. The sulphate of barytes obtained being collected, 

 washed and ignited, weighed 24*06 grs. = 8*5 gr. sulphuric 

 acid. 



What is wanting to complete the 16*26 grs. must be water. 

 For no other constituent could be obtained. 

 Thus, it appears that the salt is composed of, 



Sulphuric acid 8*5 



Chlorine 0*12 



Protoxide of manganese . . 5*445 

 Water 2*195 



16*26 

 The chlorine was doubtless combined with manganese, 

 probably in the state of tris-chloride. We must, therefore, 

 subtract 0*36 from the protoxide of manganese. The re- 

 mainder, 5*085, is the quantity of manganese in combina- 

 tion with the sulphuric acid. Now, 5*1 is to 8*5 as 4*5 to 

 7*5. So that the salt is composed very nearly of 



IJ atom sulphuric acid . . 7*5 



1 atom protoxide of manganese 4*5 



2 atoms water 2*25 



14*25 

 The water was rather less than two atoms. Probably a 

 little had been driven off in the attempt to dry the salt by 

 heat. 



