PLATE VII 



INDICATORS FOR ALKALIES AND ACIDS. 



Litmus. 



Congo red. 



3 



Phenolphthalein. 





flethy 1- orange ; Dimethj I-amido- 

 azobenzol ; Tropseolin D. 



5 



Alizarin for acids. 



I ffelmann's test for lactic acid. 



Gunzburg's phloroglucin- vanillin 

 test or Boas' resorcin test for free hy- 

 drochloric acid. 



Methyl-violet. 



Haematoxylin. 



A ffocn & Co Lie/i. Baltimore., .Wd. 



The colors on the left indicate alkaline, those on the right acid reaction. 

 For explanation see page in Index. 



