186 



ESSAY XIV. 



it is kept constantly stirred with a wooden spoon. 1 When 

 the whole has been added, the mixture should be left to 

 stand still for a few hours, during which the green colour 

 will be deposited at the bottom. The clear ley is then to 

 be poured off, and a few cans of hot water added under 

 continual agitation. When the colour has fallen again to 

 the bottom, the clear water is to be poured off. This lixi- 

 viation with hot water should be repeated a second time. 



When the matter has been thus well washed, 2 the whole 

 together is to be shaken out on a stretched linen cloth ; 

 and when the water has all dropped away, the colour is to 

 be placed in small lumps on grey paper, and dried by a 

 gentle heat. From the quantities above prescribed, 1 Ib. 

 together with 6J oz. of a fine green colour are obtained. 



1 As an effervescence takes place in this operation, the vessel in 

 which the mixture is made should not be too small. It should contain 

 about sixteen cans. 



2 The water with which the colour is lixiviated contains a little 

 arsenic, and must therefore l>e thrown out in a place to which cattle 

 have no access. 



