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 — 



zncl + 6 zno 4-12 ho. 



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

 By 500° all water is driven oflf, and there remains zncl + 6 

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

 general expression is 



zw c/ 4- 6 zw o 4- 3ho -f 3 HO 4- 3ho + 3 ho 



and comparing some similar chlorides, there is, 



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



2 zn cl -{- 6z?i o — basic chloride of zinc dry. 

 S u cl -^ 6 no — strong muriatic acid. 



4 zn cl -{• 6 zn o -\- 12 ho — hydrated oxychloride of zinc. 



5 H c/ 4- 6 ho 4- 12 ho — muriatic acid with a constant 



boiling point. 



• Another oxychloride, having the composition 

 zw c/ 4- 9 zw o 4- 15 ho 

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

 may best be considered as 



(zn cZ 4- 6 z« o 4- 13 h o) 4- 3 (zn o ho), 

 giving ultimately 



(zw c/ 4- 6 z;2 o 4- 3 ho 4- 3 {zno 4- 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 



