ELISHA MITCHELL SCIENTIFIC SOCIETY. 2$ 



then some six hours upon a sand bath. The residue was washed, 

 dried and analyzed with the following results : 



I. ,6200 grams of substance gave .3585 grams AgCl. p, c. C1. = I4.20. 

 The water was determined and CI. calculated on a dry basis=:i4.68. 



II. .5003 grams of substance gave .2950 grams AgCl. p. c. CI. = 14. 57. 



No water in the specimen. 

 III. .5650 grams of substance gave .3265 grams AgCl. p. c. CI. = 14.29, 



Calculated water free= 14.54. 



IV. 1.3345 grams of s\xbstance gave i. 5340 grams PbSO 4 p. c. Pb. 78.52. 



Free of waters 81. 14, 



V. HgO in air-dried substance = 3.33 p. c. 



I. II. III. IV. V, 

 Pbg calculated p. c. 82.56 found p. c. 81.14 



O ^' " 3-31 " 



CI2 " *' 14.13 " " 14.68 14-57 14-54 



HgO '' " 3-46 '• " 3.33 



Again between ten and eleven grams of the chloride was heated 

 wth 175 c.c. ammonia solution for twelve hours on a water-bath, then 

 washed and dried as before. 



I. .145 grams of substance gave .0525 grams AgCl. p. c. CI. = 8.61, 



Water-free = 8. 70. 

 IL .4935 grams of substance gave .1490 grams AgCl. p. c. CI. = 7.48. 



Water-free=7.56. 



III. .5035 grams of substance gave .1594 grams AgCl. p. c. CI. = 7.81. 



VVater-free=7.89. • 

 IV. 1.5353 grams of substance gave 1.9420 grams PbSO^ p. c. Pb=86.3l. 



Water-free=87.26. 



I. II. III. IV. 



Pb4 calculated p. c. 87.53 found p. c. 87.26. 



CI2 " " 7.48 " 8.70 7.56 7.89 



O3 '* " 4.99 



These two experiments then would point to the formation of two 

 entirely different bodies, the first having the formula PbCl.,. PbO. 

 HgO., the second the formula PbCL. SPbO. HoO. 



^To test the correctness of these results two equal amounts of the 

 chloride (about five grams) were taken, ammonia solution added 

 and the two then heated, one upon sand-bath and the other upon 

 water-bath. As the one on the sand-bath was kept at a brisk boil, 

 evaporation was faster and more of the ammonia had to be added 

 to replace that which was thus lost. Hence to the chloride upon 



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