APPENDIX 333 



EXP. 47. Throw some aluminum foil into a test tube containing 

 some strong potassium hydroxide solution and warm gently. 



EXP. 48. Hang two strips of cotton, one of which has been soak- 

 ing in a solution of aluminum acetate, over a glass rod, and suspend 

 them in a solution of logwood for five minutes. Remove them to a 

 beaker and wash with plenty of water. Observe whether the dye 

 adheres more firmly to one sample than to the other. 



MERCURY 



NOTE. As mercury and its compounds corrode lead pipes, the slops must be 

 thrown into jars specially provided, and not into the sink. 



EXP. 49. Place about 5 cc. of mercurous nitrate solution in a 

 test-tube, and dilute with an equal amount of water, then add 

 potassium hydroxide. 



EXP. 50. Dilute 5 cc. of mercuric nitrate solution with an equal 

 quantity of water and add potassium hydroxide. 



EXP. 51. Add hydrochloric acid to mercurous nitrate solution. 

 EXP. 52. Add hydrochloric acid to mercuric nitrate solution. 



EXP. 53. Add stannous chloride solution, drop by drop, to a 

 test-tube half filled with mercuric chloride solution. 



EXP. 54. Allow a drop of mercurous nitrate to remain for a few 

 moments on a clean copper surface, rinse the copper in a little water, 

 wipe dry with filter-paper, then heat in flame. 



TIN AND LEAD 



EXP. 55. Allow hydrogen sulphide gas to act on stannous 

 chloride. 



EXP. 56. Allow hydrogen sulphide gas to act on stannic 

 chloride. 



EXP. 57. Drop some tinfoil into a test-tube with hydrochloric 

 acid and observe effect in cold and heat. 



EXP. 58. Place tin-foil in a crucible, set the latter inside the 

 fume-closet and add strong nitric acid. 



