5. Concentrated nitric acid.

6. Dilute nitric acid, 1 acid to 20 water.

7. Acetic acid.

8. Caustic soda solution, 5 grams in 100 c.c. water.

9. Ammonia (strong).

10. Dilute ammonia, 1 strong ammonia to 10 water.

11. Carbonate of soda solution, 6 grams in 100 c.c. water.

12. Bleaching powder solution, 2° Tw.

13. Bisulphite of soda, 72° Tw.

14. Stannous chloride, 10 grams crystals in 100 c.c. water, with a little hydrochloric acid.