186 



There is generated by the action of water on these basic 

 ammoniacal compounds, an oxychloride of zinc of a very re- 

 markable character : it is — 



zn c/ + 6 zra o + 12 ho. 



dried, it is reduced at 212° to 9 ho + and by 300° to 6 ho. 

 By 500° all water is driven off, and there remains zncl -\-6 

 zn o which exposed to the air absorbed 3 ho. Hence the 

 general expression is 



zncl-\-Qzno + 3ho +3 ho +3ho +3 ho 

 and comparing some similar chlorides, there is, 



1 ca.cl 4- 6 ho crystallized chloride of calcium. 



2 zn cl + 6 zn o — basic chloride of zinc dry. 



3 h cl -J- 6 ho — strong muriatic acid. 



4 zn cl + 6 zn o -{- 12 ho — ■ hydrated oxychloride of zinc. 

 5h cl + 6 ho + 12 ho — muriatic acid with a constant 



boiling point. 



• Another oxychloride, having the composition 



zn cl + 9 zn o + 15 ho 



which dried and exposed to air, absorbs 6 ho. Hence it 

 may best be considered as 



(zn cl + 6 zn o + 12 h o) + 3 (zn o ho), 



giving ultimately 



(zn cl -f- 6 zn o + 3 ho -f 3 (zno + ho) 



Mr. Petrie then read the following Report, from the 

 Committee of Antiquities : — 



At a meeting of the council, on Monday last, the Presi- 

 dent read the following letter, which he received from Mr. 

 Drummond, the Under Secretary of State. 



Dublin Castle, May 19, 1838. 

 " My dear Sir, 



" I am informed, that in levelling a 

 mound in the Phoenix Park, on the eastern flank of the 



