386 SALTS 



1 atom acetic acid . 6-25 



1 atom oxide of copper 7-50 



3 atoms water . . 3-375 



17-125 



It is, therefore, a subsesquacetate of copper. 

 Triacetate, jQ The insoluble salt is obtained by allowing 

 verdigris to swell up in water, filtering through 

 coarse linen, which retains the impurities, and 

 lets the salt pass through. The crystalline scales 

 are now separated by pouring the whole of the fil- 

 tered solution on fine cambric ; they should be 

 pressed closely together and washed a few times 

 with water ; after this they must be transferred 

 to a paper filter and thoroughly washed with 

 alcohol. When thus obtained, the salt consti- 

 tutes a mass of small light blue shining crystal- 

 line scales, having a deeper and purer blue colour 

 than the subsesquacetate of copper. When dried 

 in 212, it loses a very little hygroscopic water, 

 and does not alter its apppearance. From 100 

 parts of this salt Berzelius obtained 64*25, and in 

 another experiment 64'7 parts of oxide of copper: 

 the acetic acid determined, as in the preceding 

 salt, amounted to 26'995 per cent. Hence, the 

 constituents of the salt are 



Acetic acid 26-995 or 6-25 



Oxide of copper 64-475 - 14-928 

 Water . 8-530 - 1-975 



100000 



