JAMES SHANKS 213 



made to flow into the filtering vessel, so as to 

 keep the solid matter constantly covered with 

 liquid, and continue such addition of water 

 until the solution running off is free or nearly 

 free from caustic soda. 



This patent appears never to have gone 

 beyond the experimental stage; we cannot 

 learn that the process was ever adopted 

 in the works. 



The one process with which Shanks' name 

 is permanently associated is not connected 

 with any patent. When he came to Lanca- 

 shire, and for some years afterwards, he 

 found in use the old apparatus employed for 

 lixiviating the black-ash, but when he under- 

 took the management of Crosfield's works 

 he introduced the system of vats which, to 

 the present day, everywhere goes by the 

 name of "Shanks' vats." 



The lixiviation of black-ash would at first 

 appear to be an exceedingly simple matter; 

 it is, however, one of the stages in the 

 production of alkali requiring great care and 

 attention. The main points to keep in view 

 are: 



i. To secure a good production by wash- 

 ing out completely the soda contained in the 

 black-ash. 



