Phil. Mag. S. 6. Vol. 2. PL VII. 



Figure 2. Baric chloride ; 30 diam. ; Fig ure 3. Baric chloride ; 30 diam. ; 

 exposure 0'04 sec. exposure 0*08 sec. 



Figure 4. Sodic nitrate ; 30 diam. ; 

 exposure 0*10 sec. 



Figure 5. Sodic nitrate ; 30 diam. ; 

 exposure 0*12 sec. 



Figure G. Baric chloride; 110 diam. 

 exposure 010 sec. 



Figure 7. Oupric sulphate ; 110 diam. ; 

 exposure 0*12 sec. 



