*4 Mr. kir wan’s Experiments and Obfervations , See. 
green ; fo that certainly the nickel is not precipitated ; the white 
precipitate in this cafe feems to be (lightly dephlogiflieated 
arfenic. 
This regulus alfo caufes a white precipitate in the nitrous 
folution of cobalt, but the liquor (hill continues red. 
With regard to the marine acid, copper precipitates the 
regulus, but volatile alkalies do not ftrike a blue with this folu- 
tion, which (hews the copper unites with the arfenic. Iron 
alfo precipitates the arfenic. Tin is foluble in marine folution 
of arfenic* but I could obferve no precipitate, nor does regulus 
of arfenic precipitate tin. 
Neither wifmuth nor the regulus of arfenic precipitate each 
other from the marine acid in 16 hours. Regulus of antimony 
is alfo adled upon by the marine folution of arfenic, though it 
caufes no precipitate, nor does the regulus of arfenic precipitate 
it. 
