392  CONTRIBUTIONS    TO   ECONOMIC    GEOLOGY,  1905. 
sent  back  to  the  absorption  tower,  while  the  gas  is  pumped  through  cleansing  tanks  to  t 
gasometer.     It  is  then  compressed  in  a  three-step  compressor  to  the  liquid  state  and    i 
shipped  in  steel  cylinders   holding  25  to  60  pounds.     In  this   process  the  weight  of  g$  ; 
obtained  is  about  50  pe/-  cent  of  the  weight  of  the  magnesite  used.     The  gas  is  shipped  a 
over  the  Pacific  coast  and  the  Southwestern  States.     It  is  used  in  refrigeration  and  in  mat 
ing  soda  water  and  other  aerated  beverages. 
This  same  company  is  preparing  to  make  light  magnesia  alba,  by  the  Pattinson  process 
to  be  used  as  an  absorbent  for  nitroglycerin  in  the  manufacture  of  dynamite.  It  is  sait 
to  make  a  very  superior  absorbenl  for  the  best  grades  of  dynamite. 
