S68 



Account of a compound Salt. ^' [Mait^ 



muriate of silver was then collected and fused ; it weighed 6S 

 grains, which indicate 10*42 of muriatic acid. 



IV. A solution of soda was added to 100 grains of this salt 

 dissolved in water as long as it continued to occasion any preci- 

 pitate ; the precipitate was then well washed, and exptised to a 

 red heat ; it weiglied 16 grains^ and was found to be pure oxide 

 of manganese. 



V. One hundred grains of this salt -were exposed to heat in an 

 iron crucible ; at a low red heat it began to melt and boil ; 

 when-the temperature had increased to a bright red, the boiling 

 ceased, and the whole remained in the state of a thin, transpa- 

 rent fluid ; when weighed in this state it was found to have lost 

 16 grains, which may .be considered the quantity of water that 

 it contains. 



VI. One hundred grains of this salt were dissolved in water;- 

 the solution separated from the insoluble substances, and evapo- 

 rated to saturation ; a quantity of alcohol, equal to four times its 

 bulk, was then added to it, and the mixture agitated ; sulphate 

 of soda quickly precipitated, and the muriate of manganese 

 remained dissolved by the alcohol. The precipitate was then ~ 

 separated from the solution, treated several times with small 

 quantities of alcohol, for the purpose of dissolving any muriate 

 that might adhere to it, and exposed to a red heat, when it 

 weighed 55 grains. The alcohol was then evaporated, and the 

 residual salt fused ; it weighed 26'5 grains. The salts thus 

 procured were dissolved in water, and tested by the muriate of 

 barytes and sulphate of silver ; the separation was not perfectly 

 complete ; the sulphate of barytes obtained denoted very nearly 

 the same quantity of sulphate of soda that the muriate of silver 

 did of muriate of manganese ; but in neither case did the 

 precipitates indicate a grain of the respective salts. The results 

 obtained by this experiment agree very nearly with those of the 

 preceding : this salt may therefore be considered as composed of 



30-63 Sulphuric acid- 



10*67 Muriatic acid. 



24-07 Sodp. 



16*5 Oxide of manganese. 



1-25 Ox de of lead. 



16- Water. 



•83 Loss. 



100-00 



I have found the quantity of uncombined manganese remarked 

 in the first experiment to vary in proportion to the purity of the 

 salt ; the weight given there may be considered as rather more 

 than average of several j it is therefore probable tliatits presence 



1 , 



