26 JOURNAL OF THE 



the sand-bath 145 c.c. were added, whereas 65 c.c. sufficed for that 

 heated on the water-bath. The object was to keep the ammonia, 

 solution strong enough to give always a decided ammonia smell. 

 Once or 1 wice, however, that upon the sand-bath became very weak. 

 The residue from the sand-bath mixture was washed. The sub- 

 stance was creamy yellow and was unchanged, by heating up to 200=^ C - 



I. .5060 grams of substance gave .2745 grams AgCl. p. c. Q.=^i3.4i 



Water-free= 13.89. 

 II. 1.2700 grams of substance gave 1.4730 grams PbSO^ p. c. Pb=78.45 



Water-free = 81.26. 



The formula then is PbClg. PbO. 



The residue from the water-bath was much yellower and becante 

 a deep yellow on heating. The analysis gave the foll6wiiig results : 



I. .520 grams of subs-tance gave .1370 grams AgCl. p. c. CI, =6. 51 



Water-free=7.28. 



Thi« corresponds with the per centage of chlorine calculated for 

 the tribasic chloride Pbclg. 3Pbo. 



As Mr. Wood had to leave the research at this point, further iik- 

 quiry into this formation of the oxysalts of lead was left to Mr, 

 Borden, who contributed the next paper. 



Chemical Laboratory, U. N. C, Feb. 9, 1.884. 



EXAMINATION OF IRON ORES FROM CHAPEL 



HILL MINE. ^ 



J. C. ROBERTA. 



I'he samples were not selected so as to ^ive the eommefcial valu0 

 Of the mine but were chosen to illustrate the different grades of the 

 ore and its decomposition so far as possible. The samples taken 

 were as follows: 1° A fairly compact Brown Hematite; 2° A crum- 



