PLATE 1. 



Fig. 1. Spectrum of carbon point in hydrochloric acid. (Lines of impurities, 

 which are iron, calcium, and aluminium.) 



Fig. 2. Spectrum of carbon point in solution of sodium chloride. 



Fig. 3. Spectrum of carbon point in solution of potassium chloride. 



Fig. 4. Spectrum of platinum point in solution of barium chloride. 



Fig. 5. Spectrum of platinum point in solution of strontium chloride. 



Fig. 6. a. Spectrum of spark in air between lead terminals. 



b. Spectrum of arc in air. Metallic lead on carbon terminals. 



c. Spectrum of lead point in hydrochloric acid. 



