OF ARTS AND SCIENCES. 



19 



Experiment No. 5. 



In order to see if the salt IICu AsO^ could be prepared by taking the 

 exact amount (if arsenic trioxide and copper sulphate necessary to 

 form it, the following ^Jroportious were taken : — 



Copper sulphate, 

 Arsenic trioxide, 

 Sodium carbonate, 



The solution of arsenic in the sodium carbonate was boiled, and 

 added, while boiling, to the solution of copper sulphate. And the 

 ebullition was continued till all the carbonic aoid was driven off. The 

 precipitate was washed by decantation once or twice, and then divided 

 into three portions ; the first was merely drained, the second was 

 washed a little, and the third was washed until arsenic ceased to be 

 found in the wash-water. These portions were numbered respectively, 

 VIIL, IX., X. They all contained basic copper sulphate, and No. VIII. 

 probably contained a little sodium sulphate. 



Analysis No. VIII. 



99.34 



Analysis No. IX. 



100.02 



Analysis No. X. 



99.51 



