Sanger and Black. -Arsenic by Gutzeit Method. 



PLAt 1. 



ii^ 



5 10 15 20 



25 30 35 40 50 60 70 



Fig. 1. 



Standard Arsenic Bands in Micromilligrams of AS2O3 



Initial. 



mt 



5 10 15 20 



25 30 



Fig. 2. 



Standard Arsenic Bands in Micromilligrams of As^Og 

 Hydrochloric Acid Development. 



35 40 50 60 70 



pROc Amer. Acad. Arts and Sciences. Vol. XLIII. 



